lex 755 145 6 202604 5301433760 7457 0ustar pcjdiskd00_o-̀\ `-:D$4 `vQP`[̀rUWVS}` l E19}5\E09E tNB9|u95ha(hahaP:jP5\y\` C\M e[^_US022902|Y؃d2P:jP5l .y l j525` y ` j525dxd=02ul @02 l ` \\02` d]UUd-%sUWVSuV9Vrj[V_ F[F19,cU <ߋV9Vr j V_ F FVSwPs`C9,c~ U <uC9~PvPhV2` V9Vrj V'_ F FC9,cbV9Vr j]V_ F]Fe[^_State #%d is non-accepting - US]=82t \a<t \a<uh\c=`>tYSh5)v` S5)+u 5))H9Hr j PF_)P @]%s: Dangerous trailing context in rule at line %d UWVS}9] |uMH U)4}tLL:<uA}u;92Mff%@t)45Ah_h `v` B9~C9] }e[^_ associated rule line numbers: %dUWVS}E 10 h0c\9\|e )d )`hd`99lt@9~9~ cFlC9\}VlPclh'W}_9P؅}C$)ȃuO9Orj WR_ G GlhFW)_ C9~O9Or j W_ G GP[^_ out-transitions: jam-transitions: EOF UVS]M 19,c~!@Y}؋B9,chS_PS19,c~ %B9,chS=_PSUs9sr j S"_ C C[^consistency check failed in epsclosure()UWVSM U=xuj5X i`xE1E9]U4p <|^G9=X AX X P:jPur Ej5X 5`r ``4p  ct EMUuC9]lE9})`M4T =p }<G9=X AX X P:jPu'r Ej5X 5`r ``p  ctEUMT <t[EU9X AX X P:jPuq Ej5X 5`q `MU]h p <G9=X AX X P:jPu'q Ej5X 5`q ``p  ctEMUT <t[EM9 X AX X P:jPup Ej5X 5`p `UM]E9}E9}8`Up <} }hVjE9}~ˋMU UMMU Ee[^_U22P:jP5( o ( j525= %d ) yy_c = yy_meta[yy_c];yy_current_state = yy_nxt[yy_base[yy_current_state] + yy_c];Uuh,\h-6h"#h`-=-t4,2Ph-_h- hp h-Ðyy_ec[*yy_cp]*yy_cpyy_ec[*++yy_cp]*++yy_cpwhile ( (yy_current_state = yy_nxt[yy_current_state][%s]) > 0 )++yy_cp;yy_current_state = -yy_current_state;register const struct yy_trans_info *yy_trans_info; register YY_CHAR yy_c; for ( yy_c = %s; (yy_trans_info = &yy_current_state[yy_c])->yy_verify == yy_c; yy_c = %s )yy_current_state += yy_trans_info->yy_nxt;dowhile ( yy_base[yy_current_state] != %d ); while ( yy_current_state != %d ); UVS.=)t..=)t.=)Sh.Q=\c~Ah" `9 `rj h `_ `  `h/D=\c~ hp.  `9 `rj h `C_ `  `h/=)h"hA/hv/Sh/]h/Vh/B=\c~ h"vh/i=\c~A `9 `rj h `{_ `  `Ehp hph 0h" jh/ hp  =?t5?h#05H]hO0<_=82u =?uhn u h h e[^(*yy_cp ? yy_ec[*yy_cp] : %d)(*yy_cp ? *yy_cp : %d)if ( *yy_cp )yy_current_state = yy_nxt[yy_current_state][%s];yy_current_state += yy_current_state[%s].yy_nxt;yy_current_state = yy_NUL_trans[yy_current_state];*yy_state_ptr++ = yy_current_state;US]t;=D2u2=)t 5)h2 5)h3Pu_ #.=)t.PP_t@=D2t7=)u=)uh,3 h" =)tPh:3=)tPhk3. PtB=D2t9hpR  h;)? h3,  =)u =)t(=82t h3 register YY_CHAR *yy_cp = yy_c_buf_p;yy_is_jam = (yy_current_state == 0);yy_current_state = yy_nxt[yy_current_state][%d]; yy_is_jam = (yy_current_state <= 0);register int yy_c = %d; yy_trans_info = &yy_current_state[yy_c];yy_is_jam = (yy_trans_info->yy_verify != yy_c);%dyy_is_jam = (yy_base[yy_current_state] == %d); yy_is_jam = (yy_current_state == %d); if ( ! yy_is_jam )UVS1=\c~ =82t hg5B  `9 `rj h `]_ `  `=D2th3h5v=)t5)h5~_h5M=)tO5)h 6V_hA/h"6h/hK6zh5)h{6]S_ S=82t h3A5=?t5?h~65H]h6_tt=)u =)tb `9 `rj h `_ `  `h6h"hp e[^ + (yy_bp[-1] == '\n' ? 1 : 0)yy_current_state = yy_start_state_list[yy_start%s];yy_current_state = yy_start;if ( yy_bp[-1] == '\n' )++yy_current_state;yy_state_ptr = yy_state_buf;U=)t 8=P t8Ph8Vh9=P t&h;9hT9q =82thh9Uh3HÐyy_accliststate # %d accepts: [%d], Meta-Equivalence Classes: yy_meta%d = %d yy_baseyy_defyy_nxtyy_chkUWVS(Cj525ETc\c=82E]T]< \a4-@Phy:=,2~P_ 9-|?8c<t Dc<u8c=H]<8c46C9-}3-@Ph:=,2~PB_ 9-|,Dc<uTcDc4.6C9-}Y3e[^_UVSu] =)=\cu huT8=)u =)t5\chT5)8_ hT5) _)$ t hT5)]_t hU=P2a)h5Ah1Uh `踩_5)5)hRUh `蚩_hsUh `舩_=`>t. `9 `rjbh `j_ `b `=ct/ `9 `rjdh `3_ `d `=?t/ `9 `rjIh `_ `I `=P]t/ `9 `rjih `ä_ `i `=Au/ `9 `rjLh `苤_ `L `= 2t/ `9 `rjph `S_ `p `=l2t/ `9 `rjsh `_ `s `=t/ `9 `rjth `_ `t `=d2t/ `9 `rjTh `諣_ `T `=P2t/ `9 `rjvh `s_ `v `=,cu0 `9 `rj8h `8_ `8 `hUh ` _=)t- `9 `rjfh `_ `f `=)t/ `9 `rjFh `跢_ `F `=)t/ `9 `rjeh `_ `e `=-t/ `9 `rjmh `G_ `m `5<Ut5<hUh `_  `9 `rj h `_ `  `5)542hUh `賥_52525,2hUh `菥_(HPhUh `v_ =\cu hU4=)u =)t5\chUh `9_ h&Vh `%_=P thLVh ` _5)5AhoVh `_5Pc5(chVh `Τ_=02uhVh `賤_A5la5ha02 l `   P52RhVh `p_5(hWh `X_ 5c5$ch8Wh `:_=)t&5,25paVh^Wh `_ 5,25x2-]4p52,2x2PhrWh `ˣ_5)5A5-hWh `解_x2paP52x2IPhWh `u_5TchWh `]_ 5\2h Xh `E_ 5@c5x2h"Xh `'_=)t$5,c5,c5pahCXh `_=-t$5pa5,c5IhhXh `͢_5c5)5, hXh `詢_5P:hXh `葢_ VhXh `~_ u軡_%s: Assuming use of deprecated -c flag is really intended to be -C -C flag must be given separatelyunknown -C option '%c'-S flag must be given separatelyunknown flag '%c'full table and -Cm don't make sense togetherfull table and -I are (currently) incompatiblefull table and -F are mutually exclusivewcould not create %slex.backtrackcould not create lex.backtrackrcan't open skeleton file %s/tmp/flexXXXXXXcan't open temporary action file %sUWVSP]?l2d2(2P2))c 2`>82\>8 t2?)-A1,cU A0U 8-0x&ƻ~3E>9EM$$egggggggggggHfgg,gggPgggpgggggggggggggggggggggg f0ffgggg`ggggggg|ggggggg`>5Ahbh `C_ t h\b u#)-)C<3u3t,hLchbcI_)uhpc  )02A! )hc5<_$u5<hcL =0uGc c c c h*_0hLc50u_`au50hc @c(Lc(42,22c, P:Pc(cpa)t ))c$c\2 c\cP IL X2)L]=)tEDY9,c|J@YT:C9,c},cX:+9,c|@YX:C9,c}`e[^_#define FLEX_DEBUG#define YY_CHAR unsigned char#define YY_CHAR charfatal parse errorUh=ct hk_=,cu hkhk_h `qthkj=,t!h@Y[pa)7=)t5,ch@YhX:® pa ,cpa,c@Y@Y@Y}أ)=)tyÐU)jhs4cj5)^Aj5)I)j5)4T j5)p j5) h j5) cj5))j5)H XcdjjdL:j5Xc))(jj(Aj5)kIj5)V2j5)AIj5),`2j5)c2djjdl j52` j52dhajh\X Ajh8cj5AwDc2 jh Yda2jh;( j52&/ }t <1t$<2t281s2E12E1)yG9} Å}Ce[^_ } ; U=t ~#hLsՖ_)t ÐU `9 `rj h `_ `  `)=) ~7 `9 `rj h `詌_ `  `)t %s: %s Uu5Ahth `U_jÐ%s: fatal internal error, %s Uu5Ah@th ` _jÐUj_EEP_PK@ÐUSu uS_ S?USu uS谘_ S%xUEPhuu襘_E# line %d "%s" U=(t"=At5(5X2h0uu_ %5dU=t  ~3 `9 `rj,h `_ `, `=t uh `hpuŎ_. `9 `rj,h `螊_ `, `t uhuu_ÐU=t  ~3 `9 `rj,h `N_ `, `1=t uh `hpu%_. `9 `rj,h `_ `, `t uhuuG_Ð%dUUEEPhvR_EUWVSuFPиH9$ w|x|x|x|x|x|x|x|x|x|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx0xt 5(hg~5`a_ } tE(L:= 2t)4hq~h `軄_ I(L:~fh~5`a~_~#Sh~h~h~5`a\_Vh~h5`a>_h5`a+_5`ae[^UVSu] uFt?S)4) A9~4c9}e[^bad state type in mark_beginning_as_normal()US]H tQuBT <u7p <t 4h <t4 hԀ]UWVSu} u*t$hVSWSe[^_UuiPÐUS])T <u p <thNPShh5SPOá)4S,؋]UWVSu} uhVPWV )T <up <u c<uS4] )T <u!p <u c<u S4(hVPVpơ)S4J)e[^_UVSu)T <up <u VR hVSSVe[^UWVS}] CPW7E}uWPP;h9]~$WVPPC9]VuoPWelje[^_input rules are too complicated (>= %d NFA states)US]42 )9 42)=|~Ph'P:j5)54c 4cj5)5Ap Aj5)5)U )j5)5T : T j5)5p  p j5)5h  h j5)5 c cj5)5) )j5)5H  H 424c)AT p h  c) ( H  ) |5u (c%=)th@YhX:؅u,cP42]found too many transitions in mkxtion()UUM p <u ÐT <u h <th:ÐPch  too many rules (> %d)!U( Xc9 (|DP:XcdXcjP5L:, L:j5Xc5) )=(~hhn() X2 multiple <> rules for start condition %scase YY_STATE_EOF(%s): US9Hc|kcI<t`24h\k5 cI`24h5`at|_ C9Hc}5`a]UE(2PBUSu uSL_ S"%s", line %d: %s Uu5X25(huh `{_ÐUout of memoryyacc stack overflowsyntax errorYY_FATAL_ERROR( "flex scanner jammed" )ECHO; YY_BREAK INITIALunknown error processing section 1bad start condition list'^' operator results in sub-optimal performancewarning - all start conditions already have <> rulesunrecognized ruleundeclared start condition %s%s: warning - trailing context rule at line %d made variable because of preceding '|' action trailing context used twicebad iteration valuesiteration value must be positivenegative range in character classUWVSEhX}_$hX}_(=$tu h $ ,=(=048D]@2$2 ,M=0} 4ME}(9Eu+5(M+ $M}E}S5$_$S5(_(=$tuh~(EM$E}M9E A}}~x=$2}Fa$2} $2$2xOG $29 Pu1$2=2=A]=@2 @2M=$2}`$2} $2=u}9=t8uM9Hu8| =$298uX}#5(@w_5$2w_1@2}"ttohӈ@2?}x  T:65c5H25<25AV`)=Hc9=)W5c)cI4Sc )UI}) Hc9 )~=P P = 2h^L65c5H25<25AV)=Hc9=)5c)cA4c )UA}) Hc9 )~U65c5H25<25AV)=A9=)K)2<u%5cI4 )I) A9 )~=P P = 2h^65c5H25<25AVP)=A9=)a)2<u%5cA4< )A) A9 )~Hc)=A9=)<I5c)<uHcHc) A9 )~҃=Hcuhhȉh\]"KIt8HcHcc=Ih `rn_h2<2=h2t*=<2u!(@Pv8A =T2=H26h]=)t#h]hAa=T:tV=h2t =<2t05X25Ahh `m_h>h `m_h2<2)=h2u T2 <2T2H2h4 j P54  65A=)=h2t=<2uA=T2=H2h26vl=)th]A )=h2t h2 T2 <2T2)6*65Ah2vR#h2v h2v:h2~9~~}hyrv5A~uvjv Pvvv5h2~hv5AEjvvO A*h2~ hFHPvgPv=usBgd j Pf5d g=)t=5,c5,ch@YhX:d ` 4l  \ PT2d Pz=Au%j` 4l =\

@~>Z6%6vf!>9~~h;=P]t:~@~~Zv%F>@~>Z6k%N )>9#5)vd)9 )~1=At=lQ9~%A lQv5A=P]t>@~>Z6%6vfd1=At=lQ9>%A lQv5A]AlQdA9=P]t>@~>Z6R%T26PvAhAe[^_wwyC;<5CB3CCC21C4x/ww IxEFHJXYVUWKMLKQPQQSSSTchgiidddabx![Zkmloqrs__`____&#"&&,*-,,)))() ;<8uuu76721?2/.wwGHUvvvNORcfeddd!kjop___\___&#&&*+++*(  9:@uu77A?vvdd\\__&&'++  uvdd__&&+ dd__&&]^]^$% >     !"#$%&'( !"#$%&'()*+   +U~[ZYIBhl4(x_wd'/+qP {R-NSVOgZceQ`\OdLIhEMMMmFJG+5#H3/'s9=AEINUoON@9Q?0"7gLRZNKQ %2?LYfs '.:AMZgt~#/;AMS_flq}TTUUVVWWT XXT YYZZ[[\\]]T^^YY__``aaT%bb%%cdTTTTTeTTfgThTTTTTTTijTTTTTklmTnTooonpTTTTTTqTTTTTTTTTjTTrsTtjTuTTvTwwwTTxTTTyTTzTT{TT|}}T}~~~TTTTTTTTTTTTTeTTfTTTTTTThTTTTTiiTTTTTTklTmTnoooTpTTqTTTTTTuvTvTwwwxTyzT{T}}}T~~~TTTTTTTTTTTTTTTTTTiiTTooTTwwT~~TTTTTTTTi TooTww~~TTTTiiooww~~TTooww~~TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT./0//...1.............222222222222222222....3433.5.6.....7.......888888888888888888...:;::<=>>`S>a?U@ARSRRRSRRhbwij`[aB>CDCC<\=E]>>bU>?U@AUFdhxedfRij^eQfB>KKLKKKKKKKKKKKKKKKKKKKMMMMMMMMMMMMNMMMMOKKKTTUTTTTTTTTTVTTTTWTTTTXXXXXXXXXXXXXXXXXXTTT[zz}}P\{{]~~ON^kklkkmkkknkkkkokkkkkkkppppppppppppqpppprsktwMLKJIxHGFEDCBA.@=< ;&9876!"!!54  21                  -()((/+>*//////!"!!()((?&# ??????9999999999999GGGGGGGGGGGGGIIIIIIIIIIIIIQQQQQQQQQQQQQUUUUUUUUUUUUUZZZZZZZZZZZZZ_____________cccccccccccccggggggggggggguuuuuuuuuuuuuyyyyyyyyyyyyy|||||||||||||  Tv   v         YYPJ$JHH$%%%%%%%%%%%%%''TT'',,TT,,0TTT03TTT3T:TTT:-TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTEAbI AbeEe===HG # #!"nFi !"$n#$++++>>E+////i$3333+D''''RRR??CB'A@='%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%((((::::;9:CCCC87C(65(,,,,4:,2C,,61-+6666*6666666%6BB#BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB   .  ..      !!!!((((///////UUUUUUUUUUUUUVVVVVVVVVVVVVWWWWWWWWWWWWWXXXXXXXXXXXXXYYYYYYYYYYYYYZZZZZZZZZZZZZ[[[[[[[[[[[[[\\\\\\\\\\\\\]]]]]]]]]]]]]^^^^^^^^^^^^^_____________`````````````aaaaaaaaaaaaabbbbbbbbbbbbbcccccccccccccdddddddddddddeeeefffffffffffffgggggggggggghhhhiiiiiiiiiiijjjjjjjjjjjjkkkkkkkkkkkkklllllllllllmmmmmmmmmmmmmnnnnnnnnnnooooppppppppppppqqqqrrrrrrrrrrrrsssssssssssstttttttttttuuuuuuuvvvvvvvvvvvvww~wwxxxxxxxxxxxxxyy{yyuyyyyyyyzzrzzqzzzzzzz{{of{{{{]{{{{||W||||||||||}}P}}}}}}}ON}~~IG~~@?751- TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTwarning - %%used/%%unused have been deprecateddynamic memory failure building %t tableunrecognized '%' directiveillegal characterincomplete name definitionunrecognized %used/%unused constructbad row in translation table%s%%%% end of prolog undefined {name}bad start condition namemissing quotebad character inside {}'smissing }bad name in {}'s YY_BREAK EOF encountered inside an actionflex scanner jammedfatal flex scanner internal error--no action foundUWVSDž==u =u < `=u  `=Dt55DNh@5,DHߋ  uANf4TxH0X LpHjDž 5j5 25L2@_eX2h `Dž L h `hDž'Dž'h'X2,cuPC_,u h1<19,c~,C9,cD +hZ 5L2h\]H_@ huX25j5 25L2)?_X2U 5j5 25L2>_5j5 25L2>_X25j5 25L2>_5L2SG_0߹ЍX| + t + uKƄ+Ph\]+@=@u h-X2eX2'5L2tt2)h5L2聩t?hhX2D DžhǾ5L2% ,D u'"L2,D uDžCHK=L2) 2HX25L2h5`a;_ h5`a;_X2!h5`a;_1} L29%%Dž<tQh5`a{;_ )a < " H_=L2) 2WHG{ H_=L2) 2WHG$^ <% > \>HK=L2) 2H<\>  L 5L2h\]tC_h\]t2lao02@Ph\]S0\]ЍX~5L2\]PI K[ 5L2h\]B_ 2ƀ[]h]]ƅu h5L2j) 0ЍX|5L23P Ky5L2j( L2oL2+X2 L>8H_=L2) 2WHG>5L2h\]A_h 費^L2g"h%fX2"`H_=L2) 2WHGgH_=L2) 2WHG)2-L2mH_=L2) 2WHG-^L2]85L2詨2,h3}hMҹX2}hW讹hM蒹X2<5L2h5`a5_ 5L2<82z5L2h5`aj5_ 5L2ġI8 :X25L2h5`a$5_ =<tu5`ahh4_Dž5L2h5`a4_ <5L2h5`a4_ <x5L2h5`aj4_ !P5L2h5`aB4_ #(X25L2h5`a4_ =<5`ahh4_5L2h5`a3_ 5L2h5`a3_ hs65L2٥%2%5L2蹥%25j5 25L23_h `h3_ `9 `rj h `._ `  `j2_+5L2NHD@L9w=5L25Q=L2.t txK:X t!L2 IyAz=X55D 5L25=L2D@L=L2Ph `h1_ `9 `rj h `l-_ `  `j0_[^_fatal flex scanner internal error--end of buffer missedfatal error - scanner input buffer overflowread() in flex scanner failedUVSDZ L2IL@B9vJh `hO0_ `9 `rj h `j,_ `  `j/_5+5L219} AC@9|DxtLD@ )H= ~ SLh `h/_ `9 `rj h `+_ `  `j._PDPP5S/_P5_ L}Jh `ho/_ `9 `rj h `J+_ `  `jo._=Lu/uD@D@1ۉ L LDBBDRBL2؍e[^UVSL2 x uA5L295>tNEEfUS]t-(h S0(_u$Sh荘< `(]symbol table memory allocation failedUWVS}uWƋUtsWC1_t4[uj+_Åu hxkUtC%C{U S USU1e[^_Ujeh`cu ju1PDÐUjeh`cu@ÐUVSu] uV4tsVo0_u [ue[^UWVS]u 11;tHG<uȍe[^_name defined twiceUS]jehtaju dPSΓPmt h]Ujehtau@ Ð0#define %s %d start condition %s declared twiceUWVS]޿dt5AShf<+_ A5)95A()P:jP5A7 Aj5)5I Ij5)52 2j5)5I Ij5)5`2˚ `2j5)5c谚 cSf A`2jeh@QjPtShu肨h} AAha AI2u 4Ie[^_Ujeh@uF@ÐUWVSDžMIpa)9}uhu SMIMI9 )}t5tlM9 d>t`uQE=)t6 )Pu ǍM9~btS+PSu{ 9}lj`uMI9~[MIU+U9|uu uiuu u uhu 5pauRhW4,?u 5paPM9|uu u  [^_UWVSx2pa-)=-t 5pah.h)8 I =pa=I,2x2@927'95x21۹9 pa|l=pa=daȋ=-t<.~". ~CA9 pa}Sh,2@P5IF95x2T[^_USAAP:jP58c> 8cj5A5Dc# Dch@jDcS$_]UWVS} ~$=- -+pa\  Cpa9A}BDc|uރ<uЃ}  G=\ upa DcDc9tt:u9u9{؍e[^_UAPj5Dc#_-\ x2=-tA.9pa|J.)@9pa}pa)UVS5,2F5H]--pa9A}-8c5T]4Dc5H]49pa|-8c Dc-5H]4B9pa}ߋ5-5?H]( 5-4B pa9pa| 44x B9pa}e[^U WVSx21ۋ5x25papa92+2 2P:jP5da蘏 da9pa|G da}<u2;C2}>End Marker*Something Weird* - tok: %d val: %d US=)tÃtuI)=L u!hT/L =L u L 1ۃ=d2=$t#(@Phbh `/_ $^q[/;( "$<?>Bj}{lLQ 3  `9  `r  ` `  `9  `rj h `_s `  `ch `hf_h `hi_  `9  `r j 1 `  `h `hle_=L ~$oh\]hp 2޸[9$52hu=2|2 `Pu52hyX  `9  `r2Ph `H_t ` 2 `]52h52hh `_3hhh `_52Shh `_؋]UVS)u1҃<)t)B8uӅt4)ЃKue[^US)=)tЃ;uhV_]U=,u,Ð<<SL$ T$\$̀} أ4[ÐVSt$ \$T$t'Ѐ:t@8u)PRV Su[^' : can't load library 'Incompatible version. Too many libraries. No such library. Permission denied. Exec format error. Unspecified error. ) ( UWVSl$|$T=TPV>̀} ى 44jh0huj9$\thjh:jh.jh"jh-jhA jhUj̀򐐋H %t 93D$ځ%9u 9}D$T$t;jh0hujujhjd̀򐐃>L[^_]þT=Tt.jhiphl0hoj>u֐1۸̀[^_]/lib/libc.so.4Jump table 4.1<<<<<<<<<<<<<<<<<<<<<<<<<<@(#)ccl.c 5.2 (Berkeley) 6/18/90@(#)dfa.c 5.2 (Berkeley) 6/18/90@(#)ecs.c 5.2 (Berkeley) 6/18/90@(#)gen.c 5.2 (Berkeley) 6/18/90static const short int %s[%d] = { 0, static const long int %s[%d] = { 0, static const yy_state_type %s[%d] = { 0, static const %s %s[%d] = { 0, static const YY_CHAR %s[%d] = { 0, @(#) Copyright (c) 1990 The Regents of the University of California. All rights reserved. @(#)main.c 5.3 (Berkeley) 6/18/902.3`P@(#)misc.c 5.3 (Berkeley) 2/26/91@(#)nfa.c 5.2 (Berkeley) 6/18/90@(#)parse.y 5.2 (Berkeley) 6/18/90 G:# M ,KD+A @NH23O.C>9=8%J0 6*4< " ""&1')-7;?F1I5///LEE!!!(B$"  FEDC:86543-10)'$/.&       ^ <."([  ^ $|/*+?{^>,$")],}-]}}  ")*+5.3  !#$%3 ,4-/2(0'1&@(#) Copyright (c) 1989 The Regents of the University of California. @(#) All rights reserved. @(#) $Header: /usr/fsys/odin/a/vern/flex/RCS/scan.l,v 2.8 90/05/26 16:53:23 vern Exp $ (LBL)@(#)sym.c 5.2 (Berkeley) 6/18/90@(#)tblcmp.c 5.2 (Berkeley) 6/18/90@(#)yylex.c 5.2 (Berkeley) 6/18/900`,<_v4README 644 145 6 2067 5301433653 7563 0ustar pcjdiskThis is blex, Lex from the Berkeley distribution. It contains source from the BSD distribution. See the file COPYING for details. Your legal responsibilites are yours. I did this because I had run into some incompatibilities between gnu flex and stuff I needed to compile. Several other people on c.o.l were having problems with flex as well, so I decided to upload this binary. This version seems to work better with the byacc that is on tsx-11 (sources/usr.bin/byacc.lzh) than with bison -y. I used byacc to do the initial compilation. If you want to build it yourself: grab the sources from agate.berkeley.edu:/pub/386BSD/386bsd-0.1/filesystem/usr/src/usr.bin/lex/. Modify pathnames.h to point to wherever you want the lex.skel to reside. (Mine is in /usr/local/lib/lex.skel.) Copy initscan.c to scan.c. Yacc -d parse.y. Compile all source files except initscan.c to object format. Link all the object files into the lex binary. Lex scan.l, rebuild scan.c, and relink. Hope this helps someone...if you have questions, bugs, etc., mail: ifai645@ccwf.cc.utexas.eduCOPYING 644 145 6 5164 5227640025 7737 0ustar pcjdiskFlex carries the copyright used for BSD software, slightly modified because it originated at the Lawrence Berkeley (not Livermore!) Laboratory, which operates under a contract with the Department of Energy: /*- * Copyright (c) 1991 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * Vern Paxson of Lawrence Berkeley Laboratory. * * The United States Government has rights in this work pursuant * to contract no. DE-AC03-76SF00098 between the United States * Department of Energy and the University of California. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)COPYING 5.2 (Berkeley) 4/12/91 */ This basically says "do whatever you please with this software except remove this notice". Note that the "flex.skel" scanner skeleton carries no copyright notice. You are free to do whatever you please with scanners generated using flex; for them, you are not even bound by the above copyright. usr/local/lib/lex.skel 644 0 0 45412 5300775040 13223 0ustar rootroot/* A lexical scanner generated by flex */ /* scanner skeleton version: * * $Header: flex/RCS/flex.skel,v 2.13 90/05/26 17:24:13 vern Exp $ * * @(#)lex.skel 5.5 (Berkeley) 5/6/91 */ #define FLEX_SCANNER #include #include #ifdef __STDC__ #define YY_USE_PROTOS #endif /* cfront 1.2 defines "c_plusplus" instead of "__cplusplus" */ #ifdef c_plusplus #ifndef __cplusplus #define __cplusplus #endif #endif #ifdef __cplusplus #include /* use prototypes in function declarations */ #define YY_USE_PROTOS #endif #ifdef YY_USE_PROTOS #define YY_PROTO(proto) proto #else #define YY_PROTO(proto) () #endif /* amount of stuff to slurp up with each read */ #ifndef YY_READ_BUF_SIZE #define YY_READ_BUF_SIZE 8192 #endif /* returned upon end-of-file */ #define YY_END_TOK 0 /* copy whatever the last rule matched to the standard output */ /* cast to (char *) is because for 8-bit chars, yytext is (unsigned char *) */ /* this used to be an fputs(), but since the string might contain NUL's, * we now use fwrite() */ #define ECHO (void) fwrite( (char *) yytext, yyleng, 1, yyout ) /* gets input and stuffs it into "buf". number of characters read, or YY_NULL, * is returned in "result". */ #define YY_INPUT(buf,result,max_size) \ if ( (result = read( fileno(yyin), (char *) buf, max_size )) < 0 ) \ YY_FATAL_ERROR( "read() in flex scanner failed" ); #define YY_NULL 0 /* no semi-colon after return; correct usage is to write "yyterminate();" - * we don't want an extra ';' after the "return" because that will cause * some compilers to complain about unreachable statements. */ #define yyterminate() return ( YY_NULL ) /* report a fatal error */ /* The funky do-while is used to turn this macro definition into * a single C statement (which needs a semi-colon terminator). * This avoids problems with code like: * * if ( something_happens ) * YY_FATAL_ERROR( "oops, the something happened" ); * else * everything_okay(); * * Prior to using the do-while the compiler would get upset at the * "else" because it interpreted the "if" statement as being all * done when it reached the ';' after the YY_FATAL_ERROR() call. */ #define YY_FATAL_ERROR(msg) \ do \ { \ (void) fputs( msg, stderr ); \ (void) putc( '\n', stderr ); \ exit( 1 ); \ } \ while ( 0 ) /* default yywrap function - always treat EOF as an EOF */ #define yywrap() 1 /* enter a start condition. This macro really ought to take a parameter, * but we do it the disgusting crufty way forced on us by the ()-less * definition of BEGIN */ #define BEGIN yy_start = 1 + 2 * /* action number for EOF rule of a given start state */ #define YY_STATE_EOF(state) (YY_END_OF_BUFFER + state + 1) /* special action meaning "start processing a new file" */ #define YY_NEW_FILE \ do \ { \ yy_init_buffer( yy_current_buffer, yyin ); \ yy_load_buffer_state(); \ } \ while ( 0 ) /* default declaration of generated scanner - a define so the user can * easily add parameters */ #define YY_DECL int yylex YY_PROTO(( void )) /* code executed at the end of each rule */ #define YY_BREAK break; #define YY_END_OF_BUFFER_CHAR 0 #ifndef YY_BUF_SIZE #define YY_BUF_SIZE (YY_READ_BUF_SIZE * 2) /* size of default input buffer */ #endif typedef struct yy_buffer_state *YY_BUFFER_STATE; %% section 1 definitions go here /* done after the current pattern has been matched and before the * corresponding action - sets up yytext */ #define YY_DO_BEFORE_ACTION \ yytext = yy_bp; \ %% code to fiddle yytext and yyleng for yymore() goes here yy_hold_char = *yy_cp; \ *yy_cp = '\0'; \ yy_c_buf_p = yy_cp; #define EOB_ACT_CONTINUE_SCAN 0 #define EOB_ACT_END_OF_FILE 1 #define EOB_ACT_LAST_MATCH 2 /* return all but the first 'n' matched characters back to the input stream */ #define yyless(n) \ do \ { \ /* undo effects of setting up yytext */ \ *yy_cp = yy_hold_char; \ yy_c_buf_p = yy_cp = yy_bp + n; \ YY_DO_BEFORE_ACTION; /* set up yytext again */ \ } \ while ( 0 ) #define unput(c) yyunput( c, yytext ) struct yy_buffer_state { FILE *yy_input_file; YY_CHAR *yy_ch_buf; /* input buffer */ YY_CHAR *yy_buf_pos; /* current position in input buffer */ /* size of input buffer in bytes, not including room for EOB characters*/ int yy_buf_size; /* number of characters read into yy_ch_buf, not including EOB characters */ int yy_n_chars; int yy_eof_status; /* whether we've seen an EOF on this buffer */ #define EOF_NOT_SEEN 0 /* "pending" happens when the EOF has been seen but there's still * some text process */ #define EOF_PENDING 1 #define EOF_DONE 2 }; static YY_BUFFER_STATE yy_current_buffer; /* we provide macros for accessing buffer states in case in the * future we want to put the buffer states in a more general * "scanner state" */ #define YY_CURRENT_BUFFER yy_current_buffer /* yy_hold_char holds the character lost when yytext is formed */ static YY_CHAR yy_hold_char; static int yy_n_chars; /* number of characters read into yy_ch_buf */ #ifndef YY_USER_ACTION #define YY_USER_ACTION #endif #ifndef YY_USER_INIT #define YY_USER_INIT #endif extern YY_CHAR *yytext; extern int yyleng; extern FILE *yyin, *yyout; YY_CHAR *yytext; int yyleng; FILE *yyin = (FILE *) 0, *yyout = (FILE *) 0; %% data tables for the DFA go here /* these variables are all declared out here so that section 3 code can * manipulate them */ /* points to current character in buffer */ static YY_CHAR *yy_c_buf_p = (YY_CHAR *) 0; static int yy_init = 1; /* whether we need to initialize */ static int yy_start = 0; /* start state number */ /* flag which is used to allow yywrap()'s to do buffer switches * instead of setting up a fresh yyin. A bit of a hack ... */ static int yy_did_buffer_switch_on_eof; static yy_state_type yy_get_previous_state YY_PROTO(( void )); static yy_state_type yy_try_NUL_trans YY_PROTO(( yy_state_type current_state )); static int yy_get_next_buffer YY_PROTO(( void )); static void yyunput YY_PROTO(( YY_CHAR c, YY_CHAR *buf_ptr )); void yyrestart YY_PROTO(( FILE *input_file )); void yy_switch_to_buffer YY_PROTO(( YY_BUFFER_STATE new_buffer )); void yy_load_buffer_state YY_PROTO(( void )); YY_BUFFER_STATE yy_create_buffer YY_PROTO(( FILE *file, int size )); void yy_delete_buffer YY_PROTO(( YY_BUFFER_STATE b )); void yy_init_buffer YY_PROTO(( YY_BUFFER_STATE b, FILE *file )); #define yy_new_buffer yy_create_buffer #ifdef __cplusplus static int yyinput YY_PROTO(( void )); #else static int input YY_PROTO(( void )); #endif YY_DECL { register yy_state_type yy_current_state; register YY_CHAR *yy_cp, *yy_bp; register int yy_act; %% user's declarations go here if ( yy_init ) { YY_USER_INIT; if ( ! yy_start ) yy_start = 1; /* first start state */ if ( ! yyin ) yyin = stdin; if ( ! yyout ) yyout = stdout; if ( yy_current_buffer ) yy_init_buffer( yy_current_buffer, yyin ); else yy_current_buffer = yy_create_buffer( yyin, YY_BUF_SIZE ); yy_load_buffer_state(); yy_init = 0; } while ( 1 ) /* loops until end-of-file is reached */ { %% yymore()-related code goes here yy_cp = yy_c_buf_p; /* support of yytext */ *yy_cp = yy_hold_char; /* yy_bp points to the position in yy_ch_buf of the start of the * current run. */ yy_bp = yy_cp; %% code to set up and find next match goes here yy_find_action: %% code to find the action number goes here YY_DO_BEFORE_ACTION; YY_USER_ACTION; do_action: /* this label is used only to access EOF actions */ %% debug code goes here switch ( yy_act ) { %% actions go here case YY_END_OF_BUFFER: { /* amount of text matched not including the EOB char */ int yy_amount_of_matched_text = yy_cp - yytext - 1; /* undo the effects of YY_DO_BEFORE_ACTION */ *yy_cp = yy_hold_char; /* note that here we test for yy_c_buf_p "<=" to the position * of the first EOB in the buffer, since yy_c_buf_p will * already have been incremented past the NUL character * (since all states make transitions on EOB to the end- * of-buffer state). Contrast this with the test in yyinput(). */ if ( yy_c_buf_p <= &yy_current_buffer->yy_ch_buf[yy_n_chars] ) /* this was really a NUL */ { yy_state_type yy_next_state; yy_c_buf_p = yytext + yy_amount_of_matched_text; yy_current_state = yy_get_previous_state(); /* okay, we're now positioned to make the * NUL transition. We couldn't have * yy_get_previous_state() go ahead and do it * for us because it doesn't know how to deal * with the possibility of jamming (and we * don't want to build jamming into it because * then it will run more slowly) */ yy_next_state = yy_try_NUL_trans( yy_current_state ); yy_bp = yytext + YY_MORE_ADJ; if ( yy_next_state ) { /* consume the NUL */ yy_cp = ++yy_c_buf_p; yy_current_state = yy_next_state; goto yy_match; } else { %% code to do backtracking for compressed tables and set up yy_cp goes here goto yy_find_action; } } else switch ( yy_get_next_buffer() ) { case EOB_ACT_END_OF_FILE: { yy_did_buffer_switch_on_eof = 0; if ( yywrap() ) { /* note: because we've taken care in * yy_get_next_buffer() to have set up yytext, * we can now set up yy_c_buf_p so that if some * total hoser (like flex itself) wants * to call the scanner after we return the * YY_NULL, it'll still work - another YY_NULL * will get returned. */ yy_c_buf_p = yytext + YY_MORE_ADJ; yy_act = YY_STATE_EOF((yy_start - 1) / 2); goto do_action; } else { if ( ! yy_did_buffer_switch_on_eof ) YY_NEW_FILE; } } break; case EOB_ACT_CONTINUE_SCAN: yy_c_buf_p = yytext + yy_amount_of_matched_text; yy_current_state = yy_get_previous_state(); yy_cp = yy_c_buf_p; yy_bp = yytext + YY_MORE_ADJ; goto yy_match; case EOB_ACT_LAST_MATCH: yy_c_buf_p = &yy_current_buffer->yy_ch_buf[yy_n_chars]; yy_current_state = yy_get_previous_state(); yy_cp = yy_c_buf_p; yy_bp = yytext + YY_MORE_ADJ; goto yy_find_action; } break; } default: #ifdef FLEX_DEBUG printf( "action # %d\n", yy_act ); #endif YY_FATAL_ERROR( "fatal flex scanner internal error--no action found" ); } } } /* yy_get_next_buffer - try to read in a new buffer * * synopsis * int yy_get_next_buffer(); * * returns a code representing an action * EOB_ACT_LAST_MATCH - * EOB_ACT_CONTINUE_SCAN - continue scanning from current position * EOB_ACT_END_OF_FILE - end of file */ static int yy_get_next_buffer() { register YY_CHAR *dest = yy_current_buffer->yy_ch_buf; register YY_CHAR *source = yytext - 1; /* copy prev. char, too */ register int number_to_move, i; int ret_val; if ( yy_c_buf_p > &yy_current_buffer->yy_ch_buf[yy_n_chars + 1] ) YY_FATAL_ERROR( "fatal flex scanner internal error--end of buffer missed" ); /* try to read more data */ /* first move last chars to start of buffer */ number_to_move = yy_c_buf_p - yytext; for ( i = 0; i < number_to_move; ++i ) *(dest++) = *(source++); if ( yy_current_buffer->yy_eof_status != EOF_NOT_SEEN ) /* don't do the read, it's not guaranteed to return an EOF, * just force an EOF */ yy_n_chars = 0; else { int num_to_read = yy_current_buffer->yy_buf_size - number_to_move - 1; if ( num_to_read > YY_READ_BUF_SIZE ) num_to_read = YY_READ_BUF_SIZE; else if ( num_to_read <= 0 ) YY_FATAL_ERROR( "fatal error - scanner input buffer overflow" ); /* read in more data */ YY_INPUT( (&yy_current_buffer->yy_ch_buf[number_to_move]), yy_n_chars, num_to_read ); } if ( yy_n_chars == 0 ) { if ( number_to_move == 1 ) { ret_val = EOB_ACT_END_OF_FILE; yy_current_buffer->yy_eof_status = EOF_DONE; } else { ret_val = EOB_ACT_LAST_MATCH; yy_current_buffer->yy_eof_status = EOF_PENDING; } } else ret_val = EOB_ACT_CONTINUE_SCAN; yy_n_chars += number_to_move; yy_current_buffer->yy_ch_buf[yy_n_chars] = YY_END_OF_BUFFER_CHAR; yy_current_buffer->yy_ch_buf[yy_n_chars + 1] = YY_END_OF_BUFFER_CHAR; /* yytext begins at the second character in yy_ch_buf; the first * character is the one which preceded it before reading in the latest * buffer; it needs to be kept around in case it's a newline, so * yy_get_previous_state() will have with '^' rules active */ yytext = &yy_current_buffer->yy_ch_buf[1]; return ( ret_val ); } /* yy_get_previous_state - get the state just before the EOB char was reached * * synopsis * yy_state_type yy_get_previous_state(); */ static yy_state_type yy_get_previous_state() { register yy_state_type yy_current_state; register YY_CHAR *yy_cp; %% code to get the start state into yy_current_state goes here for ( yy_cp = yytext + YY_MORE_ADJ; yy_cp < yy_c_buf_p; ++yy_cp ) { %% code to find the next state goes here } return ( yy_current_state ); } /* yy_try_NUL_trans - try to make a transition on the NUL character * * synopsis * next_state = yy_try_NUL_trans( current_state ); */ #ifdef YY_USE_PROTOS static yy_state_type yy_try_NUL_trans( register yy_state_type yy_current_state ) #else static yy_state_type yy_try_NUL_trans( yy_current_state ) register yy_state_type yy_current_state; #endif { register int yy_is_jam; %% code to find the next state, and perhaps do backtracking, goes here return ( yy_is_jam ? 0 : yy_current_state ); } #ifdef YY_USE_PROTOS static void yyunput( YY_CHAR c, register YY_CHAR *yy_bp ) #else static void yyunput( c, yy_bp ) YY_CHAR c; register YY_CHAR *yy_bp; #endif { register YY_CHAR *yy_cp = yy_c_buf_p; /* undo effects of setting up yytext */ *yy_cp = yy_hold_char; if ( yy_cp < yy_current_buffer->yy_ch_buf + 2 ) { /* need to shift things up to make room */ register int number_to_move = yy_n_chars + 2; /* +2 for EOB chars */ register YY_CHAR *dest = &yy_current_buffer->yy_ch_buf[yy_current_buffer->yy_buf_size + 2]; register YY_CHAR *source = &yy_current_buffer->yy_ch_buf[number_to_move]; while ( source > yy_current_buffer->yy_ch_buf ) *--dest = *--source; yy_cp += dest - source; yy_bp += dest - source; yy_n_chars = yy_current_buffer->yy_buf_size; if ( yy_cp < yy_current_buffer->yy_ch_buf + 2 ) YY_FATAL_ERROR( "flex scanner push-back overflow" ); } if ( yy_cp > yy_bp && yy_cp[-1] == '\n' ) yy_cp[-2] = '\n'; *--yy_cp = c; /* note: the formal parameter *must* be called "yy_bp" for this * macro to now work correctly */ YY_DO_BEFORE_ACTION; /* set up yytext again */ } #ifdef __cplusplus static int yyinput() #else static int input() #endif { int c; YY_CHAR *yy_cp = yy_c_buf_p; *yy_cp = yy_hold_char; if ( *yy_c_buf_p == YY_END_OF_BUFFER_CHAR ) { /* yy_c_buf_p now points to the character we want to return. * If this occurs *before* the EOB characters, then it's a * valid NUL; if not, then we've hit the end of the buffer. */ if ( yy_c_buf_p < &yy_current_buffer->yy_ch_buf[yy_n_chars] ) /* this was really a NUL */ *yy_c_buf_p = '\0'; else { /* need more input */ yytext = yy_c_buf_p; ++yy_c_buf_p; switch ( yy_get_next_buffer() ) { case EOB_ACT_END_OF_FILE: { if ( yywrap() ) { yy_c_buf_p = yytext + YY_MORE_ADJ; return ( EOF ); } YY_NEW_FILE; #ifdef __cplusplus return ( yyinput() ); #else return ( input() ); #endif } break; case EOB_ACT_CONTINUE_SCAN: yy_c_buf_p = yytext + YY_MORE_ADJ; break; case EOB_ACT_LAST_MATCH: #ifdef __cplusplus YY_FATAL_ERROR( "unexpected last match in yyinput()" ); #else YY_FATAL_ERROR( "unexpected last match in input()" ); #endif } } } c = *yy_c_buf_p; yy_hold_char = *++yy_c_buf_p; return ( c ); } #ifdef YY_USE_PROTOS void yyrestart( FILE *input_file ) #else void yyrestart( input_file ) FILE *input_file; #endif { yy_init_buffer( yy_current_buffer, input_file ); yy_load_buffer_state(); } #ifdef YY_USE_PROTOS void yy_switch_to_buffer( YY_BUFFER_STATE new_buffer ) #else void yy_switch_to_buffer( new_buffer ) YY_BUFFER_STATE new_buffer; #endif { if ( yy_current_buffer == new_buffer ) return; if ( yy_current_buffer ) { /* flush out information for old buffer */ *yy_c_buf_p = yy_hold_char; yy_current_buffer->yy_buf_pos = yy_c_buf_p; yy_current_buffer->yy_n_chars = yy_n_chars; } yy_current_buffer = new_buffer; yy_load_buffer_state(); /* we don't actually know whether we did this switch during * EOF (yywrap()) processing, but the only time this flag * is looked at is after yywrap() is called, so it's safe * to go ahead and always set it. */ yy_did_buffer_switch_on_eof = 1; } #ifdef YY_USE_PROTOS void yy_load_buffer_state( void ) #else void yy_load_buffer_state() #endif { yy_n_chars = yy_current_buffer->yy_n_chars; yytext = yy_c_buf_p = yy_current_buffer->yy_buf_pos; yyin = yy_current_buffer->yy_input_file; yy_hold_char = *yy_c_buf_p; } #ifdef YY_USE_PROTOS YY_BUFFER_STATE yy_create_buffer( FILE *file, int size ) #else YY_BUFFER_STATE yy_create_buffer( file, size ) FILE *file; int size; #endif { YY_BUFFER_STATE b; b = (YY_BUFFER_STATE) malloc( sizeof( struct yy_buffer_state ) ); if ( ! b ) YY_FATAL_ERROR( "out of dynamic memory in yy_create_buffer()" ); b->yy_buf_size = size; /* yy_ch_buf has to be 2 characters longer than the size given because * we need to put in 2 end-of-buffer characters. */ b->yy_ch_buf = (YY_CHAR *) malloc( (unsigned) (b->yy_buf_size + 2) ); if ( ! b->yy_ch_buf ) YY_FATAL_ERROR( "out of dynamic memory in yy_create_buffer()" ); yy_init_buffer( b, file ); return ( b ); } #ifdef YY_USE_PROTOS void yy_delete_buffer( YY_BUFFER_STATE b ) #else void yy_delete_buffer( b ) YY_BUFFER_STATE b; #endif { if ( b == yy_current_buffer ) yy_current_buffer = (YY_BUFFER_STATE) 0; free( (char *) b->yy_ch_buf ); free( (char *) b ); } #ifdef YY_USE_PROTOS void yy_init_buffer( YY_BUFFER_STATE b, FILE *file ) #else void yy_init_buffer( b, file ) YY_BUFFER_STATE b; FILE *file; #endif { b->yy_input_file = file; /* we put in the '\n' and start reading from [1] so that an * initial match-at-newline will be true. */ b->yy_ch_buf[0] = '\n'; b->yy_n_chars = 1; /* we always need two end-of-buffer characters. The first causes * a transition to the end-of-buffer state. The second causes * a jam in that state. */ b->yy_ch_buf[1] = YY_END_OF_BUFFER_CHAR; b->yy_ch_buf[2] = YY_END_OF_BUFFER_CHAR; b->yy_buf_pos = &b->yy_ch_buf[1]; b->yy_eof_status = EOF_NOT_SEEN; } usr/man/man1/flexdoc.1 644 145 6 200165 5001441717 12665 0ustar pcjdisk.\" Copyright (c) 1991 The Regents of the University of California. .\" All rights reserved. .\" .\" new copyright; att/bsd/shared .\" This code is derived from software contributed to Berkeley by .\" Vern Paxson of Lawrence Berkeley Laboratory. .\" .\" The United States Government has rights in this work pursuant .\" to contract no. DE-AC03-76SF00098 between the United States .\" Department of Energy and the University of California. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)flexdoc.1 5.2 (Berkeley) 4/12/91 .\" .TH FLEX 1 "April 12, 1991" .SH NAME flex - fast lexical analyzer generator .SH SYNOPSIS .B flex .B [-bcdfinpstvFILT8 -C[efmF] -Sskeleton] .I [filename ...] .SH DESCRIPTION .I flex is a tool for generating .I scanners: programs which recognized lexical patterns in text. .I flex reads the given input files, or its standard input if no file names are given, for a description of a scanner to generate. The description is in the form of pairs of regular expressions and C code, called .I rules. flex generates as output a C source file, .B lex.yy.c, which defines a routine .B yylex(). This file is compiled and linked with the .B -lfl library to produce an executable. When the executable is run, it analyzes its input for occurrences of the regular expressions. Whenever it finds one, it executes the corresponding C code. .SH SOME SIMPLE EXAMPLES .LP First some simple examples to get the flavor of how one uses .I flex. The following .I flex input specifies a scanner which whenever it encounters the string "username" will replace it with the user's login name: .nf %% username printf( "%s", getlogin() ); .fi By default, any text not matched by a .I flex scanner is copied to the output, so the net effect of this scanner is to copy its input file to its output with each occurrence of "username" expanded. In this input, there is just one rule. "username" is the .I pattern and the "printf" is the .I action. The "%%" marks the beginning of the rules. .LP Here's another simple example: .nf int num_lines = 0, num_chars = 0; %% \\n ++num_lines; ++num_chars; . ++num_chars; %% main() { yylex(); printf( "# of lines = %d, # of chars = %d\\n", num_lines, num_chars ); } .fi This scanner counts the number of characters and the number of lines in its input (it produces no output other than the final report on the counts). The first line declares two globals, "num_lines" and "num_chars", which are accessible both inside .B yylex() and in the .B main() routine declared after the second "%%". There are two rules, one which matches a newline ("\\n") and increments both the line count and the character count, and one which matches any character other than a newline (indicated by the "." regular expression). .LP A somewhat more complicated example: .nf /* scanner for a toy Pascal-like language */ %{ /* need this for the call to atof() below */ #include %} DIGIT [0-9] ID [a-z][a-z0-9]* %% {DIGIT}+ { printf( "An integer: %s (%d)\\n", yytext, atoi( yytext ) ); } {DIGIT}+"."{DIGIT}* { printf( "A float: %s (%d)\\n", yytext, atof( yytext ) ); } if|then|begin|end|procedure|function { printf( "A keyword: %s\\n", yytext ); } {ID} printf( "An identifier: %s\\n", yytext ); "+"|"-"|"*"|"/" printf( "An operator: %s\\n", yytext ); "{"[^}\\n]*"}" /* eat up one-line comments */ [ \\t\\n]+ /* eat up whitespace */ . printf( "Unrecognized character: %s\\n", yytext ); %% main( argc, argv ) int argc; char **argv; { ++argv, --argc; /* skip over program name */ if ( argc > 0 ) yyin = fopen( argv[0], "r" ); else yyin = stdin; yylex(); } .fi This is the beginnings of a simple scanner for a language like Pascal. It identifies different types of .I tokens and reports on what it has seen. .LP The details of this example will be explained in the following sections. .SH FORMAT OF THE INPUT FILE The .I flex input file consists of three sections, separated by a line with just .B %% in it: .nf definitions %% rules %% user code .fi The .I definitions section contains declarations of simple .I name definitions to simplify the scanner specification, and declarations of .I start conditions, which are explained in a later section. .LP Name definitions have the form: .nf name definition .fi The "name" is a word beginning with a letter or an underscore ('_') followed by zero or more letters, digits, '_', or '-' (dash). The definition is taken to begin at the first non-white-space character following the name and continuing to the end of the line. The definition can subsequently be referred to using "{name}", which will expand to "(definition)". For example, .nf DIGIT [0-9] ID [a-z][a-z0-9]* .fi defines "DIGIT" to be a regular expression which matches a single digit, and "ID" to be a regular expression which matches a letter followed by zero-or-more letters-or-digits. A subsequent reference to .nf {DIGIT}+"."{DIGIT}* .fi is identical to .nf ([0-9])+"."([0-9])* .fi and matches one-or-more digits followed by a '.' followed by zero-or-more digits. .LP The .I rules section of the .I flex input contains a series of rules of the form: .nf pattern action .fi where the pattern must be unindented and the action must begin on the same line. .LP See below for a further description of patterns and actions. .LP Finally, the user code section is simply copied to .B lex.yy.c verbatim. It is used for companion routines which call or are called by the scanner. The presence of this section is optional; if it is missing, the second .B %% in the input file may be skipped, too. .LP In the definitions and rules sections, any .I indented text or text enclosed in .B %{ and .B %} is copied verbatim to the output (with the %{}'s removed). The %{}'s must appear unindented on lines by themselves. .LP In the rules section, any indented or %{} text appearing before the first rule may be used to declare variables which are local to the scanning routine and (after the declarations) code which is to be executed whenever the scanning routine is entered. Other indented or %{} text in the rule section is still copied to the output, but its meaning is not well-defined and it may well cause compile-time errors (this feature is present for .I POSIX compliance; see below for other such features). .LP In the definitions section, an unindented comment (i.e., a line beginning with "/*") is also copied verbatim to the output up to the next "*/". Also, any line in the definitions section beginning with '#' is ignored, though this style of comment is deprecated and may go away in the future. .SH PATTERNS The patterns in the input are written using an extended set of regular expressions. These are: .nf x match the character 'x' . any character except newline [xyz] a "character class"; in this case, the pattern matches either an 'x', a 'y', or a 'z' [abj-oZ] a "character class" with a range in it; matches an 'a', a 'b', any letter from 'j' through 'o', or a 'Z' [^A-Z] a "negated character class", i.e., any character but those in the class. In this case, any character EXCEPT an uppercase letter. [^A-Z\\n] any character EXCEPT an uppercase letter or a newline r* zero or more r's, where r is any regular expression r+ one or more r's r? zero or one r's (that is, "an optional r") r{2,5} anywhere from two to five r's r{2,} two or more r's r{4} exactly 4 r's {name} the expansion of the "name" definition (see above) "[xyz]\\"foo" the literal string: [xyz]"foo \\X if X is an 'a', 'b', 'f', 'n', 'r', 't', or 'v', then the ANSI-C interpretation of \\x. Otherwise, a literal 'X' (used to escape operators such as '*') \\123 the character with octal value 123 \\x2a the character with hexadecimal value 2a (r) match an r; parentheses are used to override precedence (see below) rs the regular expression r followed by the regular expression s; called "concatenation" r|s either an r or an s r/s an r but only if it is followed by an s. The s is not part of the matched text. This type of pattern is called as "trailing context". ^r an r, but only at the beginning of a line r$ an r, but only at the end of a line. Equivalent to "r/\\n". r an r, but only in start condition s (see below for discussion of start conditions) r same, but in any of start conditions s1, s2, or s3 <> an end-of-file <> an end-of-file when in start condition s1 or s2 .fi The regular expressions listed above are grouped according to precedence, from highest precedence at the top to lowest at the bottom. Those grouped together have equal precedence. For example, .nf foo|bar* .fi is the same as .nf (foo)|(ba(r*)) .fi since the '*' operator has higher precedence than concatenation, and concatenation higher than alternation ('|'). This pattern therefore matches .I either the string "foo" .I or the string "ba" followed by zero-or-more r's. To match "foo" or zero-or-more "bar"'s, use: .nf foo|(bar)* .fi and to match zero-or-more "foo"'s-or-"bar"'s: .nf (foo|bar)* .fi .LP Some notes on patterns: .IP - A negated character class such as the example "[^A-Z]" above .I will match a newline unless "\\n" (or an equivalent escape sequence) is one of the characters explicitly present in the negated character class (e.g., "[^A-Z\\n]"). This is unlike how many other regular expression tools treat negated character classes, but unfortunately the inconsistency is historically entrenched. Matching newlines means that a pattern like [^"]* can match an entire input (overflowing the scanner's input buffer) unless there's another quote in the input. .IP - A rule can have at most one instance of trailing context (the '/' operator or the '$' operator). The start condition, '^', and "<>" patterns can only occur at the beginning of a pattern, and, as well as with '/' and '$', cannot be grouped inside parentheses. A '^' which does not occur at the beginning of a rule or a '$' which does not occur at the end of a rule loses its special properties and is treated as a normal character. .IP The following are illegal: .nf foo/bar$ foobar .fi Note that the first of these, can be written "foo/bar\\n". .IP The following will result in '$' or '^' being treated as a normal character: .nf foo|(bar$) foo|^bar .fi If what's wanted is a "foo" or a bar-followed-by-a-newline, the following could be used (the special '|' action is explained below): .nf foo | bar$ /* action goes here */ .fi A similar trick will work for matching a foo or a bar-at-the-beginning-of-a-line. .SH HOW THE INPUT IS MATCHED When the generated scanner is run, it analyzes its input looking for strings which match any of its patterns. If it finds more than one match, it takes the one matching the most text (for trailing context rules, this includes the length of the trailing part, even though it will then be returned to the input). If it finds two or more matches of the same length, the rule listed first in the .I flex input file is chosen. .LP Once the match is determined, the text corresponding to the match (called the .I token) is made available in the global character pointer .B yytext, and its length in the global integer .B yyleng. The .I action corresponding to the matched pattern is then executed (a more detailed description of actions follows), and then the remaining input is scanned for another match. .LP If no match is found, then the .I default rule is executed: the next character in the input is considered matched and copied to the standard output. Thus, the simplest legal .I flex input is: .nf %% .fi which generates a scanner that simply copies its input (one character at a time) to its output. .SH ACTIONS Each pattern in a rule has a corresponding action, which can be any arbitrary C statement. The pattern ends at the first non-escaped whitespace character; the remainder of the line is its action. If the action is empty, then when the pattern is matched the input token is simply discarded. For example, here is the specification for a program which deletes all occurrences of "zap me" from its input: .nf %% "zap me" .fi (It will copy all other characters in the input to the output since they will be matched by the default rule.) .LP Here is a program which compresses multiple blanks and tabs down to a single blank, and throws away whitespace found at the end of a line: .nf %% [ \\t]+ putchar( ' ' ); [ \\t]+$ /* ignore this token */ .fi .LP If the action contains a '{', then the action spans till the balancing '}' is found, and the action may cross multiple lines. .I flex knows about C strings and comments and won't be fooled by braces found within them, but also allows actions to begin with .B %{ and will consider the action to be all the text up to the next .B %} (regardless of ordinary braces inside the action). .LP An action consisting solely of a vertical bar ('|') means "same as the action for the next rule." See below for an illustration. .LP Actions can include arbitrary C code, including .B return statements to return a value to whatever routine called .B yylex(). Each time .B yylex() is called it continues processing tokens from where it last left off until it either reaches the end of the file or executes a return. Once it reaches an end-of-file, however, then any subsequent call to .B yylex() will simply immediately return, unless .B yyrestart() is first called (see below). .LP Actions are not allowed to modify yytext or yyleng. .LP There are a number of special directives which can be included within an action: .IP - .B ECHO copies yytext to the scanner's output. .IP - .B BEGIN followed by the name of a start condition places the scanner in the corresponding start condition (see below). .IP - .B REJECT directs the scanner to proceed on to the "second best" rule which matched the input (or a prefix of the input). The rule is chosen as described above in "How the Input is Matched", and .B yytext and .B yyleng set up appropriately. It may either be one which matched as much text as the originally chosen rule but came later in the .I flex input file, or one which matched less text. For example, the following will both count the words in the input and call the routine special() whenever "frob" is seen: .nf int word_count = 0; %% frob special(); REJECT; [^ \\t\\n]+ ++word_count; .fi Without the .B REJECT, any "frob"'s in the input would not be counted as words, since the scanner normally executes only one action per token. Multiple .B REJECT's are allowed, each one finding the next best choice to the currently active rule. For example, when the following scanner scans the token "abcd", it will write "abcdabcaba" to the output: .nf %% a | ab | abc | abcd ECHO; REJECT; .|\\n /* eat up any unmatched character */ .fi (The first three rules share the fourth's action since they use the special '|' action.) .B REJECT is a particularly expensive feature in terms scanner performance; if it is used in .I any of the scanner's actions it will slow down .I all of the scanner's matching. Furthermore, .B REJECT cannot be used with the .I -f or .I -F options (see below). .IP Note also that unlike the other special actions, .B REJECT is a .I branch; code immediately following it in the action will .I not be executed. .IP - .B yymore() tells the scanner that the next time it matches a rule, the corresponding token should be .I appended onto the current value of .B yytext rather than replacing it. For example, given the input "mega-kludge" the following will write "mega-mega-kludge" to the output: .nf %% mega- ECHO; yymore(); kludge ECHO; .fi First "mega-" is matched and echoed to the output. Then "kludge" is matched, but the previous "mega-" is still hanging around at the beginning of .B yytext so the .B ECHO for the "kludge" rule will actually write "mega-kludge". The presence of .B yymore() in the scanner's action entails a minor performance penalty in the scanner's matching speed. .IP - .B yyless(n) returns all but the first .I n characters of the current token back to the input stream, where they will be rescanned when the scanner looks for the next match. .B yytext and .B yyleng are adjusted appropriately (e.g., .B yyleng will now be equal to .I n ). For example, on the input "foobar" the following will write out "foobarbar": .nf %% foobar ECHO; yyless(3); [a-z]+ ECHO; .fi An argument of 0 to .B yyless will cause the entire current input string to be scanned again. Unless you've changed how the scanner will subsequently process its input (using .B BEGIN, for example), this will result in an endless loop. .IP - .B unput(c) puts the character .I c back onto the input stream. It will be the next character scanned. The following action will take the current token and cause it to be rescanned enclosed in parentheses. .nf { int i; unput( ')' ); for ( i = yyleng - 1; i >= 0; --i ) unput( yytext[i] ); unput( '(' ); } .fi Note that since each .B unput() puts the given character back at the .I beginning of the input stream, pushing back strings must be done back-to-front. .IP - .B input() reads the next character from the input stream. For example, the following is one way to eat up C comments: .nf %% "/*" { register int c; for ( ; ; ) { while ( (c = input()) != '*' && c != EOF ) ; /* eat up text of comment */ if ( c == '*' ) { while ( (c = input()) == '*' ) ; if ( c == '/' ) break; /* found the end */ } if ( c == EOF ) { error( "EOF in comment" ); break; } } } .fi (Note that if the scanner is compiled using .B C++, then .B input() is instead referred to as .B yyinput(), in order to avoid a name clash with the .B C++ stream by the name of .I input.) .IP - .B yyterminate() can be used in lieu of a return statement in an action. It terminates the scanner and returns a 0 to the scanner's caller, indicating "all done". Subsequent calls to the scanner will immediately return unless preceded by a call to .B yyrestart() (see below). By default, .B yyterminate() is also called when an end-of-file is encountered. It is a macro and may be redefined. .SH THE GENERATED SCANNER The output of .I flex is the file .B lex.yy.c, which contains the scanning routine .B yylex(), a number of tables used by it for matching tokens, and a number of auxiliary routines and macros. By default, .B yylex() is declared as follows: .nf int yylex() { ... various definitions and the actions in here ... } .fi (If your environment supports function prototypes, then it will be "int yylex( void )".) This definition may be changed by redefining the "YY_DECL" macro. For example, you could use: .nf #undef YY_DECL #define YY_DECL float lexscan( a, b ) float a, b; .fi to give the scanning routine the name .I lexscan, returning a float, and taking two floats as arguments. Note that if you give arguments to the scanning routine using a K&R-style/non-prototyped function declaration, you must terminate the definition with a semi-colon (;). .LP Whenever .B yylex() is called, it scans tokens from the global input file .I yyin (which defaults to stdin). It continues until it either reaches an end-of-file (at which point it returns the value 0) or one of its actions executes a .I return statement. In the former case, when called again the scanner will immediately return unless .B yyrestart() is called to point .I yyin at the new input file. ( .B yyrestart() takes one argument, a .B FILE * pointer.) In the latter case (i.e., when an action executes a return), the scanner may then be called again and it will resume scanning where it left off. .LP By default (and for purposes of efficiency), the scanner uses block-reads rather than simple .I getc() calls to read characters from .I yyin. The nature of how it gets its input can be controlled by redefining the .B YY_INPUT macro. YY_INPUT's calling sequence is "YY_INPUT(buf,result,max_size)". Its action is to place up to .I max_size characters in the character array .I buf and return in the integer variable .I result either the number of characters read or the constant YY_NULL (0 on Unix systems) to indicate EOF. The default YY_INPUT reads from the global file-pointer "yyin". .LP A sample redefinition of YY_INPUT (in the definitions section of the input file): .nf %{ #undef YY_INPUT #define YY_INPUT(buf,result,max_size) \\ result = ((buf[0] = getchar()) == EOF) ? YY_NULL : 1; %} .fi This definition will change the input processing to occur one character at a time. .LP You also can add in things like keeping track of the input line number this way; but don't expect your scanner to go very fast. .LP When the scanner receives an end-of-file indication from YY_INPUT, it then checks the .B yywrap() function. If .B yywrap() returns false (zero), then it is assumed that the function has gone ahead and set up .I yyin to point to another input file, and scanning continues. If it returns true (non-zero), then the scanner terminates, returning 0 to its caller. .LP The default .B yywrap() always returns 1. Presently, to redefine it you must first "#undef yywrap", as it is currently implemented as a macro. As indicated by the hedging in the previous sentence, it may be changed to a true function in the near future. .LP The scanner writes its .B ECHO output to the .I yyout global (default, stdout), which may be redefined by the user simply by assigning it to some other .B FILE pointer. .SH START CONDITIONS .I flex provides a mechanism for conditionally activating rules. Any rule whose pattern is prefixed with "" will only be active when the scanner is in the start condition named "sc". For example, .nf [^"]* { /* eat up the string body ... */ ... } .fi will be active only when the scanner is in the "STRING" start condition, and .nf \\. { /* handle an escape ... */ ... } .fi will be active only when the current start condition is either "INITIAL", "STRING", or "QUOTE". .LP Start conditions are declared in the definitions (first) section of the input using unindented lines beginning with either .B %s or .B %x followed by a list of names. The former declares .I inclusive start conditions, the latter .I exclusive start conditions. A start condition is activated using the .B BEGIN action. Until the next .B BEGIN action is executed, rules with the given start condition will be active and rules with other start conditions will be inactive. If the start condition is .I inclusive, then rules with no start conditions at all will also be active. If it is .I exclusive, then .I only rules qualified with the start condition will be active. A set of rules contingent on the same exclusive start condition describe a scanner which is independent of any of the other rules in the .I flex input. Because of this, exclusive start conditions make it easy to specify "mini-scanners" which scan portions of the input that are syntactically different from the rest (e.g., comments). .LP If the distinction between inclusive and exclusive start conditions is still a little vague, here's a simple example illustrating the connection between the two. The set of rules: .nf %s example %% foo /* do something */ .fi is equivalent to .nf %x example %% foo /* do something */ .fi .LP The default rule (to .B ECHO any unmatched character) remains active in start conditions. .LP .B BEGIN(0) returns to the original state where only the rules with no start conditions are active. This state can also be referred to as the start-condition "INITIAL", so .B BEGIN(INITIAL) is equivalent to .B BEGIN(0). (The parentheses around the start condition name are not required but are considered good style.) .LP .B BEGIN actions can also be given as indented code at the beginning of the rules section. For example, the following will cause the scanner to enter the "SPECIAL" start condition whenever .I yylex() is called and the global variable .I enter_special is true: .nf int enter_special; %x SPECIAL %% if ( enter_special ) BEGIN(SPECIAL); blahblahblah ...more rules follow... .fi .LP To illustrate the uses of start conditions, here is a scanner which provides two different interpretations of a string like "123.456". By default it will treat it as as three tokens, the integer "123", a dot ('.'), and the integer "456". But if the string is preceded earlier in the line by the string "expect-floats" it will treat it as a single token, the floating-point number 123.456: .nf %{ #include %} %s expect %% expect-floats BEGIN(expect); [0-9]+"."[0-9]+ { printf( "found a float, = %f\\n", atof( yytext ) ); } \\n { /* that's the end of the line, so * we need another "expect-number" * before we'll recognize any more * numbers */ BEGIN(INITIAL); } [0-9]+ { printf( "found an integer, = %d\\n", atoi( yytext ) ); } "." printf( "found a dot\\n" ); .fi Here is a scanner which recognizes (and discards) C comments while maintaining a count of the current input line. .nf %x comment %% int line_num = 1; "/*" BEGIN(comment); [^*\\n]* /* eat anything that's not a '*' */ "*"+[^*/\\n]* /* eat up '*'s not followed by '/'s */ \\n ++line_num; "*"+"/" BEGIN(INITIAL); .fi Note that start-conditions names are really integer values and can be stored as such. Thus, the above could be extended in the following fashion: .nf %x comment foo %% int line_num = 1; int comment_caller; "/*" { comment_caller = INITIAL; BEGIN(comment); } ... "/*" { comment_caller = foo; BEGIN(comment); } [^*\\n]* /* eat anything that's not a '*' */ "*"+[^*/\\n]* /* eat up '*'s not followed by '/'s */ \\n ++line_num; "*"+"/" BEGIN(comment_caller); .fi One can then implement a "stack" of start conditions using an array of integers. (It is likely that such stacks will become a full-fledged .I flex feature in the future.) Note, though, that start conditions do not have their own name-space; %s's and %x's declare names in the same fashion as #define's. .SH MULTIPLE INPUT BUFFERS Some scanners (such as those which support "include" files) require reading from several input streams. As .I flex scanners do a large amount of buffering, one cannot control where the next input will be read from by simply writing a .B YY_INPUT which is sensitive to the scanning context. .B YY_INPUT is only called when the scanner reaches the end of its buffer, which may be a long time after scanning a statement such as an "include" which requires switching the input source. .LP To negotiate these sorts of problems, .I flex provides a mechanism for creating and switching between multiple input buffers. An input buffer is created by using: .nf YY_BUFFER_STATE yy_create_buffer( FILE *file, int size ) .fi which takes a .I FILE pointer and a size and creates a buffer associated with the given file and large enough to hold .I size characters (when in doubt, use .B YY_BUF_SIZE for the size). It returns a .B YY_BUFFER_STATE handle, which may then be passed to other routines: .nf void yy_switch_to_buffer( YY_BUFFER_STATE new_buffer ) .fi switches the scanner's input buffer so subsequent tokens will come from .I new_buffer. Note that .B yy_switch_to_buffer() may be used by yywrap() to sets things up for continued scanning, instead of opening a new file and pointing .I yyin at it. .nf void yy_delete_buffer( YY_BUFFER_STATE buffer ) .fi is used to reclaim the storage associated with a buffer. .LP .B yy_new_buffer() is an alias for .B yy_create_buffer(), provided for compatibility with the C++ use of .I new and .I delete for creating and destroying dynamic objects. .LP Finally, the .B YY_CURRENT_BUFFER macro returns a .B YY_BUFFER_STATE handle to the current buffer. .LP Here is an example of using these features for writing a scanner which expands include files (the .B <> feature is discussed below): .nf /* the "incl" state is used for picking up the name * of an include file */ %x incl %{ #define MAX_INCLUDE_DEPTH 10 YY_BUFFER_STATE include_stack[MAX_INCLUDE_DEPTH]; int include_stack_ptr = 0; %} %% include BEGIN(incl); [a-z]+ ECHO; [^a-z\\n]*\\n? ECHO; [ \\t]* /* eat the whitespace */ [^ \\t\\n]+ { /* got the include file name */ if ( include_stack_ptr >= MAX_INCLUDE_DEPTH ) { fprintf( stderr, "Includes nested too deeply" ); exit( 1 ); } include_stack[include_stack_ptr++] = YY_CURRENT_BUFFER; yyin = fopen( yytext, "r" ); if ( ! yyin ) error( ... ); yy_switch_to_buffer( yy_create_buffer( yyin, YY_BUF_SIZE ) ); BEGIN(INITIAL); } <> { if ( --include_stack_ptr < 0 ) { yyterminate(); } else yy_switch_to_buffer( include_stack[include_stack_ptr] ); } .fi .SH END-OF-FILE RULES The special rule "<>" indicates actions which are to be taken when an end-of-file is encountered and yywrap() returns non-zero (i.e., indicates no further files to process). The action must finish by doing one of four things: .IP - the special .B YY_NEW_FILE action, if .I yyin has been pointed at a new file to process; .IP - a .I return statement; .IP - the special .B yyterminate() action; .IP - or, switching to a new buffer using .B yy_switch_to_buffer() as shown in the example above. .LP <> rules may not be used with other patterns; they may only be qualified with a list of start conditions. If an unqualified <> rule is given, it applies to .I all start conditions which do not already have <> actions. To specify an <> rule for only the initial start condition, use .nf <> .fi .LP These rules are useful for catching things like unclosed comments. An example: .nf %x quote %% ...other rules for dealing with quotes... <> { error( "unterminated quote" ); yyterminate(); } <> { if ( *++filelist ) { yyin = fopen( *filelist, "r" ); YY_NEW_FILE; } else yyterminate(); } .fi .SH MISCELLANEOUS MACROS The macro .bd YY_USER_ACTION can be redefined to provide an action which is always executed prior to the matched rule's action. For example, it could be #define'd to call a routine to convert yytext to lower-case. .LP The macro .B YY_USER_INIT may be redefined to provide an action which is always executed before the first scan (and before the scanner's internal initializations are done). For example, it could be used to call a routine to read in a data table or open a logging file. .LP In the generated scanner, the actions are all gathered in one large switch statement and separated using .B YY_BREAK, which may be redefined. By default, it is simply a "break", to separate each rule's action from the following rule's. Redefining .B YY_BREAK allows, for example, C++ users to #define YY_BREAK to do nothing (while being very careful that every rule ends with a "break" or a "return"!) to avoid suffering from unreachable statement warnings where because a rule's action ends with "return", the .B YY_BREAK is inaccessible. .SH INTERFACING WITH YACC One of the main uses of .I flex is as a companion to the .I yacc parser-generator. .I yacc parsers expect to call a routine named .B yylex() to find the next input token. The routine is supposed to return the type of the next token as well as putting any associated value in the global .B yylval. To use .I flex with .I yacc, one specifies the .B -d option to .I yacc to instruct it to generate the file .B y.tab.h containing definitions of all the .B %tokens appearing in the .I yacc input. This file is then included in the .I flex scanner. For example, if one of the tokens is "TOK_NUMBER", part of the scanner might look like: .nf %{ #include "y.tab.h" %} %% [0-9]+ yylval = atoi( yytext ); return TOK_NUMBER; .fi .SH TRANSLATION TABLE In the name of POSIX compliance, .I flex supports a .I translation table for mapping input characters into groups. The table is specified in the first section, and its format looks like: .nf %t 1 abcd 2 ABCDEFGHIJKLMNOPQRSTUVWXYZ 52 0123456789 6 \\t\\ \\n %t .fi This example specifies that the characters 'a', 'b', 'c', and 'd' are to all be lumped into group #1, upper-case letters in group #2, digits in group #52, tabs, blanks, and newlines into group #6, and .I no other characters will appear in the patterns. The group numbers are actually disregarded by .I flex; .B %t serves, though, to lump characters together. Given the above table, for example, the pattern "a(AA)*5" is equivalent to "d(ZQ)*0". They both say, "match any character in group #1, followed by zero-or-more pairs of characters from group #2, followed by a character from group #52." Thus .B %t provides a crude way for introducing equivalence classes into the scanner specification. .LP Note that the .B -i option (see below) coupled with the equivalence classes which .I flex automatically generates take care of virtually all the instances when one might consider using .B %t. But what the hell, it's there if you want it. .SH OPTIONS .I flex has the following options: .TP .B -b Generate backtracking information to .I lex.backtrack. This is a list of scanner states which require backtracking and the input characters on which they do so. By adding rules one can remove backtracking states. If all backtracking states are eliminated and .B -f or .B -F is used, the generated scanner will run faster (see the .B -p flag). Only users who wish to squeeze every last cycle out of their scanners need worry about this option. (See the section on PERFORMANCE CONSIDERATIONS below.) .TP .B -c is a do-nothing, deprecated option included for POSIX compliance. .IP .B NOTE: in previous releases of .I flex .B -c specified table-compression options. This functionality is now given by the .B -C flag. To ease the the impact of this change, when .I flex encounters .B -c, it currently issues a warning message and assumes that .B -C was desired instead. In the future this "promotion" of .B -c to .B -C will go away in the name of full POSIX compliance (unless the POSIX meaning is removed first). .TP .B -d makes the generated scanner run in .I debug mode. Whenever a pattern is recognized and the global .B yy_flex_debug is non-zero (which is the default), the scanner will write to .I stderr a line of the form: .nf --accepting rule at line 53 ("the matched text") .fi The line number refers to the location of the rule in the file defining the scanner (i.e., the file that was fed to flex). Messages are also generated when the scanner backtracks, accepts the default rule, reaches the end of its input buffer (or encounters a NUL; at this point, the two look the same as far as the scanner's concerned), or reaches an end-of-file. .TP .B -f specifies (take your pick) .I full table or .I fast scanner. No table compression is done. The result is large but fast. This option is equivalent to .B -Cf (see below). .TP .B -i instructs .I flex to generate a .I case-insensitive scanner. The case of letters given in the .I flex input patterns will be ignored, and tokens in the input will be matched regardless of case. The matched text given in .I yytext will have the preserved case (i.e., it will not be folded). .TP .B -n is another do-nothing, deprecated option included only for POSIX compliance. .TP .B -p generates a performance report to stderr. The report consists of comments regarding features of the .I flex input file which will cause a loss of performance in the resulting scanner. Note that the use of .I REJECT and variable trailing context (see the BUGS section in flex(1)) entails a substantial performance penalty; use of .I yymore(), the .B ^ operator, and the .B -I flag entail minor performance penalties. .TP .B -s causes the .I default rule (that unmatched scanner input is echoed to .I stdout) to be suppressed. If the scanner encounters input that does not match any of its rules, it aborts with an error. This option is useful for finding holes in a scanner's rule set. .TP .B -t instructs .I flex to write the scanner it generates to standard output instead of .B lex.yy.c. .TP .B -v specifies that .I flex should write to .I stderr a summary of statistics regarding the scanner it generates. Most of the statistics are meaningless to the casual .I flex user, but the first line identifies the version of .I flex, which is useful for figuring out where you stand with respect to patches and new releases, and the next two lines give the date when the scanner was created and a summary of the flags which were in effect. .TP .B -F specifies that the .ul fast scanner table representation should be used. This representation is about as fast as the full table representation .ul (-f), and for some sets of patterns will be considerably smaller (and for others, larger). In general, if the pattern set contains both "keywords" and a catch-all, "identifier" rule, such as in the set: .nf "case" return TOK_CASE; "switch" return TOK_SWITCH; ... "default" return TOK_DEFAULT; [a-z]+ return TOK_ID; .fi then you're better off using the full table representation. If only the "identifier" rule is present and you then use a hash table or some such to detect the keywords, you're better off using .ul -F. .IP This option is equivalent to .B -CF (see below). .TP .B -I instructs .I flex to generate an .I interactive scanner. Normally, scanners generated by .I flex always look ahead one character before deciding that a rule has been matched. At the cost of some scanning overhead, .I flex will generate a scanner which only looks ahead when needed. Such scanners are called .I interactive because if you want to write a scanner for an interactive system such as a command shell, you will probably want the user's input to be terminated with a newline, and without .B -I the user will have to type a character in addition to the newline in order to have the newline recognized. This leads to dreadful interactive performance. .IP If all this seems to confusing, here's the general rule: if a human will be typing in input to your scanner, use .B -I, otherwise don't; if you don't care about squeezing the utmost performance from your scanner and you don't want to make any assumptions about the input to your scanner, use .B -I. .IP Note, .B -I cannot be used in conjunction with .I full or .I fast tables, i.e., the .B -f, -F, -Cf, or .B -CF flags. .TP .B -L instructs .I flex not to generate .B #line directives. Without this option, .I flex peppers the generated scanner with #line directives so error messages in the actions will be correctly located with respect to the original .I flex input file, and not to the fairly meaningless line numbers of .B lex.yy.c. (Unfortunately .I flex does not presently generate the necessary directives to "retarget" the line numbers for those parts of .B lex.yy.c which it generated. So if there is an error in the generated code, a meaningless line number is reported.) .TP .B -T makes .I flex run in .I trace mode. It will generate a lot of messages to .I stdout concerning the form of the input and the resultant non-deterministic and deterministic finite automata. This option is mostly for use in maintaining .I flex. .TP .B -8 instructs .I flex to generate an 8-bit scanner, i.e., one which can recognize 8-bit characters. On some sites, .I flex is installed with this option as the default. On others, the default is 7-bit characters. To see which is the case, check the verbose .B (-v) output for "equivalence classes created". If the denominator of the number shown is 128, then by default .I flex is generating 7-bit characters. If it is 256, then the default is 8-bit characters and the .B -8 flag is not required (but may be a good idea to keep the scanner specification portable). Feeding a 7-bit scanner 8-bit characters will result in infinite loops, bus errors, or other such fireworks, so when in doubt, use the flag. Note that if equivalence classes are used, 8-bit scanners take only slightly more table space than 7-bit scanners (128 bytes, to be exact); if equivalence classes are not used, however, then the tables may grow up to twice their 7-bit size. .TP .B -C[efmF] controls the degree of table compression. .IP .B -Ce directs .I flex to construct .I equivalence classes, i.e., sets of characters which have identical lexical properties (for example, if the only appearance of digits in the .I flex input is in the character class "[0-9]" then the digits '0', '1', ..., '9' will all be put in the same equivalence class). Equivalence classes usually give dramatic reductions in the final table/object file sizes (typically a factor of 2-5) and are pretty cheap performance-wise (one array look-up per character scanned). .IP .B -Cf specifies that the .I full scanner tables should be generated - .I flex should not compress the tables by taking advantages of similar transition functions for different states. .IP .B -CF specifies that the alternate fast scanner representation (described above under the .B -F flag) should be used. .IP .B -Cm directs .I flex to construct .I meta-equivalence classes, which are sets of equivalence classes (or characters, if equivalence classes are not being used) that are commonly used together. Meta-equivalence classes are often a big win when using compressed tables, but they have a moderate performance impact (one or two "if" tests and one array look-up per character scanned). .IP A lone .B -C specifies that the scanner tables should be compressed but neither equivalence classes nor meta-equivalence classes should be used. .IP The options .B -Cf or .B -CF and .B -Cm do not make sense together - there is no opportunity for meta-equivalence classes if the table is not being compressed. Otherwise the options may be freely mixed. .IP The default setting is .B -Cem, which specifies that .I flex should generate equivalence classes and meta-equivalence classes. This setting provides the highest degree of table compression. You can trade off faster-executing scanners at the cost of larger tables with the following generally being true: .nf slowest & smallest -Cem -Cm -Ce -C -C{f,F}e -C{f,F} fastest & largest .fi Note that scanners with the smallest tables are usually generated and compiled the quickest, so during development you will usually want to use the default, maximal compression. .IP .B -Cfe is often a good compromise between speed and size for production scanners. .IP .B -C options are not cumulative; whenever the flag is encountered, the previous -C settings are forgotten. .TP .B -Sskeleton_file overrides the default skeleton file from which .I flex constructs its scanners. You'll never need this option unless you are doing .I flex maintenance or development. .SH PERFORMANCE CONSIDERATIONS The main design goal of .I flex is that it generate high-performance scanners. It has been optimized for dealing well with large sets of rules. Aside from the effects of table compression on scanner speed outlined above, there are a number of options/actions which degrade performance. These are, from most expensive to least: .nf REJECT pattern sets that require backtracking arbitrary trailing context '^' beginning-of-line operator yymore() .fi with the first three all being quite expensive and the last two being quite cheap. .LP .B REJECT should be avoided at all costs when performance is important. It is a particularly expensive option. .LP Getting rid of backtracking is messy and often may be an enormous amount of work for a complicated scanner. In principal, one begins by using the .B -b flag to generate a .I lex.backtrack file. For example, on the input .nf %% foo return TOK_KEYWORD; foobar return TOK_KEYWORD; .fi the file looks like: .nf State #6 is non-accepting - associated rule line numbers: 2 3 out-transitions: [ o ] jam-transitions: EOF [ \\001-n p-\\177 ] State #8 is non-accepting - associated rule line numbers: 3 out-transitions: [ a ] jam-transitions: EOF [ \\001-` b-\\177 ] State #9 is non-accepting - associated rule line numbers: 3 out-transitions: [ r ] jam-transitions: EOF [ \\001-q s-\\177 ] Compressed tables always backtrack. .fi The first few lines tell us that there's a scanner state in which it can make a transition on an 'o' but not on any other character, and that in that state the currently scanned text does not match any rule. The state occurs when trying to match the rules found at lines 2 and 3 in the input file. If the scanner is in that state and then reads something other than an 'o', it will have to backtrack to find a rule which is matched. With a bit of headscratching one can see that this must be the state it's in when it has seen "fo". When this has happened, if anything other than another 'o' is seen, the scanner will have to back up to simply match the 'f' (by the default rule). .LP The comment regarding State #8 indicates there's a problem when "foob" has been scanned. Indeed, on any character other than a 'b', the scanner will have to back up to accept "foo". Similarly, the comment for State #9 concerns when "fooba" has been scanned. .LP The final comment reminds us that there's no point going to all the trouble of removing backtracking from the rules unless we're using .B -f or .B -F, since there's no performance gain doing so with compressed scanners. .LP The way to remove the backtracking is to add "error" rules: .nf %% foo return TOK_KEYWORD; foobar return TOK_KEYWORD; fooba | foob | fo { /* false alarm, not really a keyword */ return TOK_ID; } .fi .LP Eliminating backtracking among a list of keywords can also be done using a "catch-all" rule: .nf %% foo return TOK_KEYWORD; foobar return TOK_KEYWORD; [a-z]+ return TOK_ID; .fi This is usually the best solution when appropriate. .LP Backtracking messages tend to cascade. With a complicated set of rules it's not uncommon to get hundreds of messages. If one can decipher them, though, it often only takes a dozen or so rules to eliminate the backtracking (though it's easy to make a mistake and have an error rule accidentally match a valid token. A possible future .I flex feature will be to automatically add rules to eliminate backtracking). .LP .I Variable trailing context (where both the leading and trailing parts do not have a fixed length) entails almost the same performance loss as .I REJECT (i.e., substantial). So when possible a rule like: .nf %% mouse|rat/(cat|dog) run(); .fi is better written: .nf %% mouse/cat|dog run(); rat/cat|dog run(); .fi or as .nf %% mouse|rat/cat run(); mouse|rat/dog run(); .fi Note that here the special '|' action does .I not provide any savings, and can even make things worse (see .B BUGS in flex(1)). .LP Another area where the user can increase a scanner's performance (and one that's easier to implement) arises from the fact that the longer the tokens matched, the faster the scanner will run. This is because with long tokens the processing of most input characters takes place in the (short) inner scanning loop, and does not often have to go through the additional work of setting up the scanning environment (e.g., .B yytext) for the action. Recall the scanner for C comments: .nf %x comment %% int line_num = 1; "/*" BEGIN(comment); [^*\\n]* "*"+[^*/\\n]* \\n ++line_num; "*"+"/" BEGIN(INITIAL); .fi This could be sped up by writing it as: .nf %x comment %% int line_num = 1; "/*" BEGIN(comment); [^*\\n]* [^*\\n]*\\n ++line_num; "*"+[^*/\\n]* "*"+[^*/\\n]*\\n ++line_num; "*"+"/" BEGIN(INITIAL); .fi Now instead of each newline requiring the processing of another action, recognizing the newlines is "distributed" over the other rules to keep the matched text as long as possible. Note that .I adding rules does .I not slow down the scanner! The speed of the scanner is independent of the number of rules or (modulo the considerations given at the beginning of this section) how complicated the rules are with regard to operators such as '*' and '|'. .LP A final example in speeding up a scanner: suppose you want to scan through a file containing identifiers and keywords, one per line and with no other extraneous characters, and recognize all the keywords. A natural first approach is: .nf %% asm | auto | break | ... etc ... volatile | while /* it's a keyword */ .|\\n /* it's not a keyword */ .fi To eliminate the back-tracking, introduce a catch-all rule: .nf %% asm | auto | break | ... etc ... volatile | while /* it's a keyword */ [a-z]+ | .|\\n /* it's not a keyword */ .fi Now, if it's guaranteed that there's exactly one word per line, then we can reduce the total number of matches by a half by merging in the recognition of newlines with that of the other tokens: .nf %% asm\\n | auto\\n | break\\n | ... etc ... volatile\\n | while\\n /* it's a keyword */ [a-z]+\\n | .|\\n /* it's not a keyword */ .fi One has to be careful here, as we have now reintroduced backtracking into the scanner. In particular, while .I we know that there will never be any characters in the input stream other than letters or newlines, .I flex can't figure this out, and it will plan for possibly needing backtracking when it has scanned a token like "auto" and then the next character is something other than a newline or a letter. Previously it would then just match the "auto" rule and be done, but now it has no "auto" rule, only a "auto\\n" rule. To eliminate the possibility of backtracking, we could either duplicate all rules but without final newlines, or, since we never expect to encounter such an input and therefore don't how it's classified, we can introduce one more catch-all rule, this one which doesn't include a newline: .nf %% asm\\n | auto\\n | break\\n | ... etc ... volatile\\n | while\\n /* it's a keyword */ [a-z]+\\n | [a-z]+ | .|\\n /* it's not a keyword */ .fi Compiled with .B -Cf, this is about as fast as one can get a .I flex scanner to go for this particular problem. .LP A final note: .I flex is slow when matching NUL's, particularly when a token contains multiple NUL's. It's best to write rules which match .I short amounts of text if it's anticipated that the text will often include NUL's. .SH INCOMPATIBILITIES WITH LEX AND POSIX .I flex is a rewrite of the Unix .I lex tool (the two implementations do not share any code, though), with some extensions and incompatibilities, both of which are of concern to those who wish to write scanners acceptable to either implementation. At present, the POSIX .I lex draft is very close to the original .I lex implementation, so some of these incompatibilities are also in conflict with the POSIX draft. But the intent is that except as noted below, .I flex as it presently stands will ultimately be POSIX conformant (i.e., that those areas of conflict with the POSIX draft will be resolved in .I flex's favor). Please bear in mind that all the comments which follow are with regard to the POSIX .I draft standard of Summer 1989, and not the final document (or subsequent drafts); they are included so .I flex users can be aware of the standardization issues and those areas where .I flex may in the near future undergo changes incompatible with its current definition. .LP .I flex is fully compatible with .I lex with the following exceptions: .IP - .I lex does not support exclusive start conditions (%x), though they are in the current POSIX draft. .IP - When definitions are expanded, .I flex encloses them in parentheses. With lex, the following: .nf NAME [A-Z][A-Z0-9]* %% foo{NAME}? printf( "Found it\\n" ); %% .fi will not match the string "foo" because when the macro is expanded the rule is equivalent to "foo[A-Z][A-Z0-9]*?" and the precedence is such that the '?' is associated with "[A-Z0-9]*". With .I flex, the rule will be expanded to "foo([A-Z][A-Z0-9]*)?" and so the string "foo" will match. Note that because of this, the .B ^, $, , /, and .B <> operators cannot be used in a .I flex definition. .IP The POSIX draft interpretation is the same as .I flex's. .IP - To specify a character class which matches anything but a left bracket (']'), in .I lex one can use "[^]]" but with .I flex one must use "[^\\]]". The latter works with .I lex, too. .IP - The undocumented .I lex scanner internal variable .B yylineno is not supported. (The variable is not part of the POSIX draft.) .IP - The .B input() routine is not redefinable, though it may be called to read characters following whatever has been matched by a rule. If .B input() encounters an end-of-file the normal .B yywrap() processing is done. A ``real'' end-of-file is returned by .B input() as .I EOF. .IP Input is instead controlled by redefining the .B YY_INPUT macro. .IP The .I flex restriction that .B input() cannot be redefined is in accordance with the POSIX draft, but .B YY_INPUT has not yet been accepted into the draft. .IP - .B output() is not supported. Output from the .B ECHO macro is done to the file-pointer .I yyout (default .I stdout). .IP The POSIX draft mentions that an .B output() routine exists but currently gives no details as to what it does. .IP - The .I lex .B %r (generate a Ratfor scanner) option is not supported. It is not part of the POSIX draft. .IP - If you are providing your own yywrap() routine, you must include a "#undef yywrap" in the definitions section (section 1). Note that the "#undef" will have to be enclosed in %{}'s. .IP The POSIX draft specifies that yywrap() is a function and this is unlikely to change; so .I flex users are warned that .B yywrap() is likely to be changed to a function in the near future. .IP - After a call to .B unput(), .I yytext and .I yyleng are undefined until the next token is matched. This is not the case with .I lex or the present POSIX draft. .IP - The precedence of the .B {} (numeric range) operator is different. .I lex interprets "abc{1,3}" as "match one, two, or three occurrences of 'abc'", whereas .I flex interprets it as "match 'ab' followed by one, two, or three occurrences of 'c'". The latter is in agreement with the current POSIX draft. .IP - The precedence of the .B ^ operator is different. .I lex interprets "^foo|bar" as "match either 'foo' at the beginning of a line, or 'bar' anywhere", whereas .I flex interprets it as "match either 'foo' or 'bar' if they come at the beginning of a line". The latter is in agreement with the current POSIX draft. .IP - To refer to yytext outside of the scanner source file, the correct definition with .I flex is "extern char *yytext" rather than "extern char yytext[]". This is contrary to the current POSIX draft but a point on which .I flex will not be changing, as the array representation entails a serious performance penalty. It is hoped that the POSIX draft will be emended to support the .I flex variety of declaration (as this is a fairly painless change to require of .I lex users). .IP - .I yyin is .I initialized by .I lex to be .I stdin; .I flex, on the other hand, initializes .I yyin to NULL and then .I assigns it to .I stdin the first time the scanner is called, providing .I yyin has not already been assigned to a non-NULL value. The difference is subtle, but the net effect is that with .I flex scanners, .I yyin does not have a valid value until the scanner has been called. .IP - The special table-size declarations such as .B %a supported by .I lex are not required by .I flex scanners; .I flex ignores them. .IP - The name .bd FLEX_SCANNER is #define'd so scanners may be written for use with either .I flex or .I lex. .LP The following .I flex features are not included in .I lex or the POSIX draft standard: .nf yyterminate() <> YY_DECL #line directives %{}'s around actions yyrestart() comments beginning with '#' (deprecated) multiple actions on a line .fi This last feature refers to the fact that with .I flex you can put multiple actions on the same line, separated with semi-colons, while with .I lex, the following .nf foo handle_foo(); ++num_foos_seen; .fi is (rather surprisingly) truncated to .nf foo handle_foo(); .fi .I flex does not truncate the action. Actions that are not enclosed in braces are simply terminated at the end of the line. .SH DIAGNOSTICS .I reject_used_but_not_detected undefined or .I yymore_used_but_not_detected undefined - These errors can occur at compile time. They indicate that the scanner uses .B REJECT or .B yymore() but that .I flex failed to notice the fact, meaning that .I flex scanned the first two sections looking for occurrences of these actions and failed to find any, but somehow you snuck some in (via a #include file, for example). Make an explicit reference to the action in your .I flex input file. (Note that previously .I flex supported a .B %used/%unused mechanism for dealing with this problem; this feature is still supported but now deprecated, and will go away soon unless the author hears from people who can argue compellingly that they need it.) .LP .I flex scanner jammed - a scanner compiled with .B -s has encountered an input string which wasn't matched by any of its rules. .LP .I flex input buffer overflowed - a scanner rule matched a string long enough to overflow the scanner's internal input buffer (16K bytes by default - controlled by .B YY_BUF_SIZE in "flex.skel". Note that to redefine this macro, you must first .B #undefine it). .LP .I scanner requires -8 flag - Your scanner specification includes recognizing 8-bit characters and you did not specify the -8 flag (and your site has not installed flex with -8 as the default). .LP .I too many %t classes! - You managed to put every single character into its own %t class. .I flex requires that at least one of the classes share characters. .SH DEFICIENCIES / BUGS See flex(1). .SH "SEE ALSO" .LP flex(1), lex(1), yacc(1), sed(1), awk(1). .LP M. E. Lesk and E. Schmidt, .I LEX - Lexical Analyzer Generator .SH AUTHOR Vern Paxson, with the help of many ideas and much inspiration from Van Jacobson. Original version by Jef Poskanzer. The fast table representation is a partial implementation of a design done by Van Jacobson. The implementation was done by Kevin Gong and Vern Paxson. .LP Thanks to the many .I flex beta-testers, feedbackers, and contributors, especially Casey Leedom, benson@odi.com, Frederic Brehm, Nick Christopher, Jason Coughlin, Scott David Daniels, Leo Eskin, Chris Faylor, Eric Goldman, Eric Hughes, Jeffrey R. Jones, Kevin B. Kenny, Ronald Lamprecht, Greg Lee, Craig Leres, Mohamed el Lozy, Jim Meyering, Marc Nozell, Esmond Pitt, Jef Poskanzer, Jim Roskind, Dave Tallman, Frank Whaley, Ken Yap, and those whose names have slipped my marginal mail-archiving skills but whose contributions are appreciated all the same. .LP Thanks to Keith Bostic, John Gilmore, Craig Leres, Bob Mulcahy, Rich Salz, and Richard Stallman for help with various distribution headaches. .LP Thanks to Esmond Pitt and Earle Horton for 8-bit character support; to Benson Margulies and Fred Burke for C++ support; to Ove Ewerlid for the basics of support for NUL's; and to Eric Hughes for the basics of support for multiple buffers. .LP Work is being done on extending .I flex to generate scanners in which the state machine is directly represented in C code rather than tables. These scanners may well be substantially faster than those generated using -f or -F. If you are working in this area and are interested in comparing notes and seeing whether redundant work can be avoided, contact Ove Ewerlid (ewerlid@mizar.DoCS.UU.SE). .LP This work was primarily done when I was at the Real Time Systems Group at the Lawrence Berkeley Laboratory in Berkeley, CA. Many thanks to all there for the support I received. .LP Send comments to: .nf Vern Paxson Computer Science Department 4126 Upson Hall Cornell University Ithaca, NY 14853-7501 vern@cs.cornell.edu decvax!cornell!vern .fi usr/man/man1/lex.1 644 145 6 53725 5047312533 12024 0ustar pcjdisk.\" Copyright (c) 1990 The Regents of the University of California. .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)lex.1 5.13 (Berkeley) 7/24/91 .\" .Dd July 24, 1991 .Dt LEX 1 .Os .Sh NAME .Nm lex .Nd fast lexical analyzer generator .Sh SYNOPSIS .Nm lex .Oo .Op Fl bcdfinpstvFILT8 .Fl C Ns Ns Op Cm efmF .Fl S Ns Ns Ar skeleton .Oc .Op Ar .Sh DESCRIPTION .Nm Lex is a tool for generating .Ar scanners : programs which recognized lexical patterns in text. .Nm Lex reads the given input files, or its standard input if no file names are given, for a description of a scanner to generate. The description is in the form of pairs of regular expressions and C code, called .Em rules . .Nm Lex generates as output a C source file, .Pa lex.yy.c , which defines a routine .Fn yylex . This file is compiled and linked with the .Fl lfl library to produce an executable. When the executable is run, it analyzes its input for occurrences of the regular expressions. Whenever it finds one, it executes the corresponding C code. .Pp For full documentation, see .Em Lexdoc . This manual entry is intended for use as a quick reference. .Sh OPTIONS .Nm Lex has the following options: .Bl -tag -width Ds .It Fl b Generate backtracking information to .Va lex.backtrack . This is a list of scanner states which require backtracking and the input characters on which they do so. By adding rules one can remove backtracking states. If all backtracking states are eliminated and .Fl f or .Fl F is used, the generated scanner will run faster. .It Fl c is a do-nothing, deprecated option included for .Tn POSIX compliance. .Pp .Ar NOTE : in previous releases of .Nm Lex .Op Fl c specified table-compression options. This functionality is now given by the .Fl C flag. To ease the the impact of this change, when .Nm lex encounters .Fl c, it currently issues a warning message and assumes that .Fl C was desired instead. In the future this "promotion" of .Fl c to .Fl C will go away in the name of full .Tn POSIX compliance (unless the .Tn POSIX meaning is removed first). .It Fl d Makes the generated scanner run in .Ar debug mode. Whenever a pattern is recognized and the global .Va yy_Lex_debug is non-zero (which is the default), the scanner will write to .Li stderr a line of the form: .Pp .Dl --accepting rule at line 53 ("the matched text") .Pp The line number refers to the location of the rule in the file defining the scanner (i.e., the file that was fed to lex). Messages are also generated when the scanner backtracks, accepts the default rule, reaches the end of its input buffer (or encounters a .Tn NUL ; the two look the same as far as the scanner's concerned), or reaches an end-of-file. .It Fl f Specifies (take your pick) .Em full table or .Em fast scanner . No table compression is done. The result is large but fast. This option is equivalent to .Fl Cf (see below). .It Fl i Instructs .Nm lex to generate a .Em case-insensitive scanner. The case of letters given in the .Nm lex input patterns will be ignored, and tokens in the input will be matched regardless of case. The matched text given in .Va yytext will have the preserved case (i.e., it will not be folded). .It Fl n Is another do-nothing, deprecated option included only for .Tn POSIX compliance. .It Fl p Generates a performance report to stderr. The report consists of comments regarding features of the .Nm lex input file which will cause a loss of performance in the resulting scanner. .It Fl s Causes the .Ar default rule (that unmatched scanner input is echoed to .Ar stdout ) to be suppressed. If the scanner encounters input that does not match any of its rules, it aborts with an error. .It Fl t Instructs .Nm lex to write the scanner it generates to standard output instead of .Pa lex.yy.c . .It Fl v Specifies that .Nm lex should write to .Li stderr a summary of statistics regarding the scanner it generates. .It Fl F Specifies that the .Em fast scanner table representation should be used. This representation is about as fast as the full table representation .Pq Fl f , and for some sets of patterns will be considerably smaller (and for others, larger). See .Em Lexdoc for details. .Pp This option is equivalent to .Fl CF (see below). .It Fl I Instructs .Nm lex to generate an .Em interactive scanner, that is, a scanner which stops immediately rather than looking ahead if it knows that the currently scanned text cannot be part of a longer rule's match. Again, see .Em Lexdoc for details. .Pp Note, .Fl I cannot be used in conjunction with .Em full or .Em fast tables , i.e., the .Fl f , F , Cf , or .Fl CF flags. .It Fl L Instructs .Nm lex not to generate .Li #line directives in .Pa lex.yy.c . The default is to generate such directives so error messages in the actions will be correctly located with respect to the original .Nm lex input file, and not to the fairly meaningless line numbers of .Pa lex.yy.c . .It Fl T Makes .Nm lex run in .Em trace mode. It will generate a lot of messages to .Li stdout concerning the form of the input and the resultant non-deterministic and deterministic finite automata. This option is mostly for use in maintaining .Nm lex . .It Fl 8 Instructs .Nm lex to generate an 8-bit scanner. On some sites, this is the default. On others, the default is 7-bit characters. To see which is the case, check the verbose .Pq Fl v output for "equivalence classes created". If the denominator of the number shown is 128, then by default .Nm lex is generating 7-bit characters. If it is 256, then the default is 8-bit characters. .It Fl C Ns Op Cm efmF Controls the degree of table compression. The default setting is .Fl Cem . .Pp .Bl -tag -width Ds .It Fl C A lone .Fl C specifies that the scanner tables should be compressed but neither equivalence classes nor meta-equivalence classes should be used. .It Fl \&Ce Directs .Nm lex to construct .Em equivalence classes , i.e., sets of characters which have identical lexical properties. Equivalence classes usually give dramatic reductions in the final table/object file sizes (typically a factor of 2-5) and are pretty cheap performance-wise (one array look-up per character scanned). .It Fl \&Cf Specifies that the .Em full scanner tables should be generated - .Nm lex should not compress the tables by taking advantages of similar transition functions for different states. .It Fl \&CF Specifies that the alternate fast scanner representation (described in .Em Lexdoc ) should be used. .It Fl \&Cm Directs .Nm lex to construct .Em meta-equivalence classes , which are sets of equivalence classes (or characters, if equivalence classes are not being used) that are commonly used together. Meta-equivalence classes are often a big win when using compressed tables, but they have a moderate performance impact (one or two "if" tests and one array look-up per character scanned). .It Fl Cem (Default) Generate both equivalence classes and meta-equivalence classes. This setting provides the highest degree of table compression. .El .Pp Faster-executing scanners can be traded off at the cost of larger tables with the following generally being true: .Bd -ragged -offset center slowest & smallest -Cem -Cm -Ce -C -C{f,F}e -C{f,F} fastest & largest .Ed .Pp .Fl C options are not cumulative; whenever the flag is encountered, the previous -C settings are forgotten. .Pp The options .Fl \&Cf or .Fl \&CF and .Fl \&Cm do not make sense together - there is no opportunity for meta-equivalence classes if the table is not being compressed. Otherwise the options may be freely mixed. .It Fl S Ns Ar skeleton_file Overrides the default skeleton file from which .Nm lex constructs its scanners. Useful for .Nm lex maintenance or development. .El .Sh SUMMARY OF LEX REGULAR EXPRESSIONS The patterns in the input are written using an extended set of regular expressions. These are: .Pp .Bl -tag -width 10n -compact .It Li x Match the character 'x'. .It Li \&. Any character except newline. .It Op Li xyz A "character class"; in this case, the pattern matches either an 'x', a 'y', or a 'z'. .It Op Li abj-oZ A "character class" with a range in it; matches an 'a', a 'b', any letter from 'j' through 'o', or a 'Z'. .It Op Li ^A-Z A "negated character class", i.e., any character but those in the class. In this case, any character .Em except an uppercase letter. .It Op Li ^A-Z\en Any character .Em except an uppercase letter or a newline. .It Li r* Zero or more r's, where r is any regular expression. .It Li r+ One or more r's. .It Li r? Zero or one r's (that is, "an optional r"). .It Li r{2,5} Anywhere from two to five r's. .It Li r{2,} Two or more r's. .It Li r{4} Exactly 4 r's. .It Li {name} The expansion of the "name" definition (see above). .It Xo .Oo Li xyz Oc Ns Li "\e\&\*qfoo" .Xc The literal string: [xyz]\*qfoo. .It Li \&\eX If X is an 'a', 'b', 'f', 'n', 'r', 't', or 'v', then the .Tn ANSI-C interpretation of \ex. Otherwise, a literal 'X' (used to escape operators such as '*'). .It Li \&\e123 The character with octal value 123. .It Li \&\ex2a The character with hexadecimal value 2a. .It Li (r) Match an r; parentheses are used to override precedence (see below). .It Li rs The regular expression r followed by the regular expression s; called "concatenation". .It Li rs Either an r or an s. .It Li r/s An r but only if it is followed by an s. The s is not part of the matched text. This type of pattern is called as "trailing context". .It Li \&^r An r, but only at the beginning of a line. .It Li r$ An r, but only at the end of a line. Equivalent to "r/\en". .It Li r An r, but only in start condition s (see below for discussion of start conditions). .It Li r Same, but in any of start conditions s1, s2, or s3. .It Li <> An end-of-file. .It Li <> An end-of-file when in start condition s1 or s2. .El The regular expressions listed above are grouped according to precedence, from highest precedence at the top to lowest at the bottom. Those grouped together have equal precedence. .Pp Some notes on patterns: .Pp Negated character classes .Ar match newlines unless "\en" (or an equivalent escape sequence) is one of the characters explicitly present in the negated character class (e.g., " [^A-Z\en] "). .Pp A rule can have at most one instance of trailing context (the '/' operator or the '$' operator). The start condition, '^', and "<>" patterns can only occur at the beginning of a pattern, and, as well as with '/' and '$', cannot be grouped inside parentheses. The following are all illegal: .Pp .Bd -literal -offset indent foo/bar$ foo(bar$) foo^bar foobar .Ed .Sh SUMMARY OF SPECIAL ACTIONS In addition to arbitrary C code, the following can appear in actions: .Bl -tag -width Fl .It Ic ECHO Copies .Va yytext to the scanner's output. .It Ic BEGIN Followed by the name of a start condition places the scanner in the corresponding start condition. .It Ic REJECT Directs the scanner to proceed on to the "second best" rule which matched the input (or a prefix of the input). .Va yytext and .Va yyleng are set up appropriately. Note that .Ic REJECT is a particularly expensive feature in terms scanner performance; if it is used in .Em any of the scanner's actions it will slow down .Em all of the scanner's matching. Furthermore, .Ic REJECT cannot be used with the .Fl f or .Fl F options. .Pp Note also that unlike the other special actions, .Ic REJECT is a .Em branch ; code immediately following it in the action will .Em not be executed. .It Fn yymore tells the scanner that the next time it matches a rule, the corresponding token should be .Em appended onto the current value of .Va yytext rather than replacing it. .It Fn yyless \&n returns all but the first .Ar n characters of the current token back to the input stream, where they will be rescanned when the scanner looks for the next match. .Va yytext and .Va yyleng are adjusted appropriately (e.g., .Va yyleng will now be equal to .Ar n ) . .It Fn unput c puts the character .Ar c back onto the input stream. It will be the next character scanned. .It Fn input reads the next character from the input stream (this routine is called .Fn yyinput if the scanner is compiled using .Em C \&+\&+ ) . .It Fn yyterminate can be used in lieu of a return statement in an action. It terminates the scanner and returns a 0 to the scanner's caller, indicating "all done". .Pp By default, .Fn yyterminate is also called when an end-of-file is encountered. It is a macro and may be redefined. .It Ic YY_NEW_FILE is an action available only in <> rules. It means "Okay, I've set up a new input file, continue scanning". .It Fn yy_create_buffer file size takes a .Ic FILE pointer and an integer .Ar size . It returns a YY_BUFFER_STATE handle to a new input buffer large enough to accomodate .Ar size characters and associated with the given file. When in doubt, use .Ar YY_BUF_SIZE for the size. .It Fn yy_switch_to_buffer new_buffer switches the scanner's processing to scan for tokens from the given buffer, which must be a YY_BUFFER_STATE. .It Fn yy_delete_buffer buffer deletes the given buffer. .El .Sh VALUES AVAILABLE TO THE USER .Bl -tag -width Fl .It Va char \&*yytext holds the text of the current token. It may not be modified. .It Va int yyleng holds the length of the current token. It may not be modified. .It Va FILE \&*yyin is the file which by default .Nm lex reads from. It may be redefined but doing so only makes sense before scanning begins. Changing it in the middle of scanning will have unexpected results since .Nm lex buffers its input. Once scanning terminates because an end-of-file has been seen, .Fn "void yyrestart" "FILE *new_file" may be called to point .Va yyin at the new input file. .It Va FILE \&*yyout is the file to which .Ar ECHO actions are done. It can be reassigned by the user. .It Va YY_CURRENT_BUFFER returns a YY_BUFFER_STATE handle to the current buffer. .El .Sh MACROS THE USER CAN REDEFINE .Bl -tag -width Fl .It Va YY_DECL controls how the scanning routine is declared. By default, it is "int yylex()", or, if prototypes are being used, "int yylex(void)". This definition may be changed by redefining the "YY_DECL" macro. Note that if you give arguments to the scanning routine using a K&R-style/non-prototyped function declaration, you must terminate the definition with a semi-colon (;). .It Va YY_INPUT The nature of how the scanner gets its input can be controlled by redefining the YY_INPUT macro. YY_INPUT's calling sequence is "YY_INPUT(buf,result,max_size)". Its action is to place up to .Ar max _size characters in the character array .Ar buf and return in the integer variable .Ar result either the number of characters read or the constant YY_NULL (0 on Unix systems) to indicate EOF. The default YY_INPUT reads from the global file-pointer "yyin". A sample redefinition of YY_INPUT (in the definitions section of the input file): .Bd -literal -offset indent %{ #undef YY_INPUT #define YY_INPUT(buf,result,max_size) \e result = ((buf[0] = getchar()) == EOF) ? YY_NULL : 1; %} .Ed .It Va YY_INPUT When the scanner receives an end-of-file indication from YY_INPUT, it then checks the .Fn yywrap function. If .Fn yywrap returns false (zero), then it is assumed that the function has gone ahead and set up .Va yyin to point to another input file, and scanning continues. If it returns true (non-zero), then the scanner terminates, returning 0 to its caller. .It Va yywrap The default .Fn yywrap always returns 1. Presently, to redefine it you must first "#undef yywrap", as it is currently implemented as a macro. It is likely that .Fn yywrap will soon be defined to be a function rather than a macro. .It Va YY_USER_ACTION can be redefined to provide an action which is always executed prior to the matched rule's action. .It Va YY_USER_INIT The macro .Va YY _USER_INIT may be redefined to provide an action which is always executed before the first scan. .It Va YY_BREAK In the generated scanner, the actions are all gathered in one large switch statement and separated using .Va YY _BREAK , which may be redefined. By default, it is simply a "break", to separate each rule's action from the following rule's. .El .Sh FILES .Bl -tag -width lex.backtrack -compact .It Pa lex.skel skeleton scanner. .It Pa lex.yy.c generated scanner (called .Pa lexyy.c on some systems). .It Pa lex.backtrack backtracking information for .Fl b .It Pa flag (called .Pa lex.bck on some systems). .El .Sh SEE ALSO .Xr lex 1 , .Xr yacc 1 , .Xr sed 1 , .Xr awk 1 . .Rs .%T "lexdoc" .Re .Rs .%A M. E. Lesk .%A E. Schmidt .%T "LEX \- Lexical Analyzer Generator" .Re .Sh DIAGNOSTICS .Bl -tag -width Fl .It Li reject_used_but_not_detected undefined or .It Li yymore_used_but_not_detected undefined These errors can occur at compile time. They indicate that the scanner uses .Ic REJECT or .Fn yymore but that .Nm lex failed to notice the fact, meaning that .Nm lex scanned the first two sections looking for occurrences of these actions and failed to find any, but somehow you snuck some in via a #include file, for example . Make an explicit reference to the action in your .Nm lex input file. Note that previously .Nm lex supported a .Li %used/%unused mechanism for dealing with this problem; this feature is still supported but now deprecated, and will go away soon unless the author hears from people who can argue compellingly that they need it. .It Li lex scanner jammed a scanner compiled with .Fl s has encountered an input string which wasn't matched by any of its rules. .It Li lex input buffer overflowed a scanner rule matched a string long enough to overflow the scanner's internal input buffer 16K bytes - controlled by .Va YY_BUF_MAX in .Pa lex.skel . .It Li scanner requires \&\-8 flag Your scanner specification includes recognizing 8-bit characters and you did not specify the -8 flag and your site has not installed lex with -8 as the default . .It Li too many \&%t classes! You managed to put every single character into its own %t class. .Nm Lex requires that at least one of the classes share characters. .El .Sh HISTORY A .Nm lex appeared in .At v6 . The version this man page describes is derived from code contributed by Vern Paxson. .Sh AUTHOR Vern Paxson, with the help of many ideas and much inspiration from Van Jacobson. Original version by Jef Poskanzer. .Pp See .%T "Lexdoc" for additional credits and the address to send comments to. .Sh BUGS .Pp Some trailing context patterns cannot be properly matched and generate warning messages ("Dangerous trailing context"). These are patterns where the ending of the first part of the rule matches the beginning of the second part, such as "zx*/xy*", where the 'x*' matches the 'x' at the beginning of the trailing context. (Note that the .Tn POSIX draft states that the text matched by such patterns is undefined.) .Pp For some trailing context rules, parts which are actually fixed-length are not recognized as such, leading to the abovementioned performance loss. In particular, parts using '\&|' or {n} (such as "foo{3}") are always considered variable-length. .Pp Combining trailing context with the special '\&|' action can result in .Em fixed trailing context being turned into the more expensive .Em variable trailing context. This happens in the following example: .Bd -literal -offset indent %% abc \&| xyz/def .Ed .Pp Use of .Fn unput invalidates yytext and yyleng. .Pp Use of .Fn unput to push back more text than was matched can result in the pushed-back text matching a beginning-of-line ('^') rule even though it didn't come at the beginning of the line (though this is rare!). .Pp Pattern-matching of .Tn NUL Ns 's is substantially slower than matching other characters. .Pp .Nm Lex does not generate correct #line directives for code internal to the scanner; thus, bugs in .Pa lex.skel yield bogus line numbers. .Pp Due to both buffering of input and read-ahead, you cannot intermix calls to .Aq Pa stdio.h routines, such as, for example, .Fn getchar , with .Nm lex rules and expect it to work. Call .Fn input instead. .Pp The total table entries listed by the .Fl v flag excludes the number of table entries needed to determine what rule has been matched. The number of entries is equal to the number of .Tn DFA states if the scanner does not use .Ic REJECT , and somewhat greater than the number of states if it does. .Pp .Ic REJECT cannot be used with the .Fl f or .Fl F options. .Pp Some of the macros, such as .Fn yywrap , may in the future become functions which live in the .Fl lfl library. This will doubtless break a lot of code, but may be required for .Tn POSIX Ns \-compliance . .Pp The .Nm lex internal algorithms need documentation.