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Subject: v13i039: Public domaind M4 macro processor, Part02/02 Newsgroups: comp.sources.unix Sender: sources Approved: rsalz@uunet.UU.NET Submitted-by: Ozan Yigit <yunexus!oz> Posting-number: Volume 13, Issue 39 Archive-name: m4/part02 #! /bin/sh # This is a shell archive, meaning: # 1. Remove everything above the #! /bin/sh line. # 2. Save the resulting text in a file. # 3. Execute the file with /bin/sh (not csh) to create the files: # ack.m4 # hanoi.m4 # hash.m4 # sqroot.m4 # string.m4 # test.m4 # README # MANIFEST # m4.1 export PATH; PATH=/bin:$PATH echo shar: extracting "'ack.m4'" '(121 characters)' if test -f 'ack.m4' then echo shar: will not over-write existing file "'ack.m4'" else sed 's/^ X//' << \SHAR_EOF > 'ack.m4' Xdefine(DECR,`eval($1-1)') Xdefine(ack, `ifelse($1,0,incr($2),$2,0,`ack(DECR($1),1)', X`ack(DECR($1), ack($1,DECR($2)))')') SHAR_EOF if test 121 -ne "`wc -c < 'ack.m4'`" then echo shar: error transmitting "'ack.m4'" '(should have been 121 characters)' fi fi # end of overwriting check echo shar: extracting "'hanoi.m4'" '(215 characters)' if test -f 'hanoi.m4' then echo shar: will not over-write existing file "'hanoi.m4'" else sed 's/^ X//' << \SHAR_EOF > 'hanoi.m4' Xdefine(DECR,`eval($1-1)') Xdefine(hanoi, `trans(A, B, C, $1)') X Xdefine(moved,`move disk from $1 to $2 X') X Xdefine(trans, `ifelse($4,1,`moved($1,$2)', X `trans($1,$3,$2,DECR($4))moved($1,$2)trans($3,$2,$1,DECR($4))')') SHAR_EOF if test 215 -ne "`wc -c < 'hanoi.m4'`" then echo shar: error transmitting "'hanoi.m4'" '(should have been 215 characters)' fi fi # end of overwriting check echo shar: extracting "'hash.m4'" '(425 characters)' if test -f 'hash.m4' then echo shar: will not over-write existing file "'hash.m4'" else sed 's/^ X//' << \SHAR_EOF > 'hash.m4' Xdnl This probably will not run on any m4 that cannot Xdnl handle char constants in eval. Xdnl Xchangequote(<,>) define(HASHVAL,99) dnl Xdefine(hash,<eval(str(substr($1,1),0)%HASHVAL)>) dnl Xdefine(str, X <ifelse($1,",$2, X <str(substr(<$1>,1),<eval($2+'substr($1,0,1)')>)>) X >) dnl Xdefine(KEYWORD,<$1,hash($1),>) dnl Xdefine(TSTART, X<struct prehash { X char *keyword; X int hashval; X} keytab[] = {>) dnl Xdefine(TEND,< "",0 X};>) dnl SHAR_EOF if test 425 -ne "`wc -c < 'hash.m4'`" then echo shar: error transmitting "'hash.m4'" '(should have been 425 characters)' fi fi # end of overwriting check echo shar: extracting "'sqroot.m4'" '(238 characters)' if test -f 'sqroot.m4' then echo shar: will not over-write existing file "'sqroot.m4'" else sed 's/^ X//' << \SHAR_EOF > 'sqroot.m4' Xdefine(square_root, X `ifelse(eval($1<0),1,negative-square-root, X `square_root_aux($1, 1, eval(($1+1)/2))')') Xdefine(square_root_aux, X `ifelse($3, $2, $3, X $3, eval($1/$2), $3, X `square_root_aux($1, $3, eval(($3+($1/$3))/2))')') SHAR_EOF if test 238 -ne "`wc -c < 'sqroot.m4'`" then echo shar: error transmitting "'sqroot.m4'" '(should have been 238 characters)' fi fi # end of overwriting check echo shar: extracting "'string.m4'" '(204 characters)' if test -f 'string.m4' then echo shar: will not over-write existing file "'string.m4'" else sed 's/^ X//' << \SHAR_EOF > 'string.m4' X Xdefine(string,`integer $1(len(substr($2,1))) Xstr($1,substr($2,1),0) Xdata $1(len(substr($2,1)))/EOS/ X') X Xdefine(str,`ifelse($2,",,data $1(incr($3))/`LET'substr($2,0,1)/ X`str($1,substr($2,1),incr($3))')') SHAR_EOF if test 204 -ne "`wc -c < 'string.m4'`" then echo shar: error transmitting "'string.m4'" '(should have been 204 characters)' fi fi # end of overwriting check echo shar: extracting "'test.m4'" '(7873 characters)' if test -f 'test.m4' then echo shar: will not over-write existing file "'test.m4'" else sed 's/^ X//' << \SHAR_EOF > 'test.m4' X# X# test file for mp (not comprehensive) X# X# include string macros X# Xinclude(string.m4) X# X# create some fortrash strings for an even uglier language X# Xstring(TEXT, "text") Xstring(DATA, "data") Xstring(BEGIN, "begin") Xstring(END, "end") Xstring(IF, "if") Xstring(THEN, "then") Xstring(ELSE, "else") Xstring(CASE, "case") Xstring(REPEAT, "repeat") Xstring(WHILE, "while") Xstring(DEFAULT, "default") Xstring(UNTIL, "until") Xstring(FUNCTION, "function") Xstring(PROCEDURE, "procedure") Xstring(EXTERNAL, "external") Xstring(FORWARD, "forward") Xstring(TYPE, "type") Xstring(VAR, "var") Xstring(CONST, "const") Xstring(PROGRAM, "program") Xstring(INPUT, "input") Xstring(OUTPUT, "output") X# Xdivert(2) Xdiversion #1 Xdivert(3) Xdiversion #2 Xdivert(4) Xdiversion #3 Xdivert(5) Xdiversion #4 Xdivert(0) Xdefine(abc,xxx) Xifdef(`abc',defined,undefined) X# X# v7 m4 does this wrong. The right output is X# this is A vEry lon sEntEnCE X# see m4 documentation for translit. X# Xtranslit(`this is a very long sentence', abcdefg, ABCDEF) X# X# include towers-of-hanoi X# Xinclude(hanoi.m4) X# X# some reasonable set of disks X# Xhanoi(6) X# X# include ackermann's function X# Xinclude(ack.m4) X# X# something like (3,3) will blow away un*x m4. X# Xack(2,3) X# X# include a square_root function for fixed nums X# Xinclude(sqroot.m4) X# X# some square roots. X# Xsquare_root(15) Xsquare_root(100) Xsquare_root(-4) Xsquare_root(21372) X# X# some textual material for enjoyment. X# X[taken from the 'Clemson University Computer Newsletter', X September 1981, pp. 6-7] X XI am a wizard in the magical Kingdom of Transformation and I Xslay dragons for a living. Actually, I am a systems programmer. XOne of the problems with systems programming is explaining to Xnon-computer enthusiasts what that is. All of the terms I use to Xdescribe my job are totally meaningless to them. Usually my response Xto questions about my work is to say as little as possible. For Xinstance, if someone asks what happened at work this week, I say X"Nothing much" and then I change the subject. X XWith the assistance of my brother, a mechanical engineer, I have devised Xan analogy that everyone can understand. The analogy describes the X"Kingdom of Transformation" where travelers wander and are magically Xtransformed. This kingdom is the computer and the travelers are information. XThe purpose of the computer is to change information to a more meaningful Xforma. The law of conservation applies here: The computer never creates Xand never intentionally destroys data. With no further ado, let us travel Xto the Kingdom of Transformation: X XIn a land far, far away, there is a magical kingdom called the Kingdom of XTransformation. A king rules over this land and employs a Council of XWizardry. The main purpose of this kingdom is to provide a way for Xneighboring kingdoms to transform citizens into more useful citizens. This Xis done by allowing the citizens to enter the kingdom at one of its ports Xand to travel any of the many routes in the kingdom. They are magically Xtransformed along the way. The income of the Kingdom of Transformation Xcomes from the many toll roads within its boundaries. X XThe Kingdom of Transformation was created when several kingdoms got Xtogether and discovered a mutual need for new talents and abilities for Xcitizens. They employed CTK, Inc. (Creators of Transformation, Inc.) to Xcreate this kingdom. CTK designed the country, its transportation routes, Xand its laws of transformation, and created the major highway system. X XHazards X======= X XBecause magic is not truly controllable, CTK invariably, but unknowingly, Xcreates dragons. Dragons are huge fire-breathing beasts which sometimes Xinjure or kill travelers. Fortunately, they do not travel, but always Xremain near their den. X XOther hazards also exist which are potentially harmful. As the roads Xbecome older and more weatherbeaten, pot-holes will develop, trees will Xfall on travelers, etc. CTK maintenance men are called to fix these Xproblems. X XWizards X======= X XThe wizards play a major role in creating and maintaining the kingdom but Xget little credit for their work because it is performed secretly. The Xwizards do not wan the workers or travelers to learn their incantations Xbecause many laws would be broken and chaos would result. X XCTK's grand design is always general enough to be applicable in many Xdifferent situations. As a result, it is often difficult to use. The Xfirst duty of the wizards is to tailor the transformation laws so as to be Xmore beneficial and easier to use in their particular environment. X XAfter creation of the kingdom, a major duty of the wizards is to search for Xand kill dragons. If travelers do not return on time or if they return Xinjured, the ruler of the country contacts the wizards. If the wizards Xdetermine that the injury or death occurred due to the traveler's Xnegligence, they provide the traveler's country with additional warnings. XIf not, they must determine if the cause was a road hazard or a dragon. If Xthe suspect a road hazard, they call in a CTK maintenance man to locate the Xhazard and to eliminate it, as in repairing the pothole in the road. If Xthey think that cause was a dragon, then they must find and slay it. X XThe most difficult part of eliminating a dragon is finding it. Sometimes Xthe wizard magically knows where the dragon's lair it, but often the wizard Xmust send another traveler along the same route and watch to see where he Xdisappears. This sounds like a failsafe method for finding dragons (and a Xsuicide mission for thr traveler) but the second traveler does not always Xdisappear. Some dragons eat any traveler who comes too close; others are Xvery picky. X XThe wizards may call in CTK who designed the highway system and Xtransformation laws to help devise a way to locate the dragon. CTK also Xhelps provide the right spell or incantation to slay the dragon. (There is Xno general spell to slay dragons; each dragon must be eliminated with a Xdifferent spell.) X XBecause neither CTK nor wizards are perfect, spells to not always work Xcorrectly. At best, nothing happens when the wrong spell is uttered. At Xworst, the dragon becomes a much larger dragon or multiplies into several Xsmaller ones. In either case, new spells must be found. X XIf all existing dragons are quiet (i.e. have eaten sufficiently), wizards Xhave time to do other things. They hide in castles and practice spells and Xincatations. They also devise shortcuts for travelers and new laws of Xtransformation. X XChanges in the Kingdom X====================== X XAs new transformation kingdoms are created and old ones are maintained, XCTK, Inc. is constantly learning new things. It learns ways to avoid Xcreating some of the dragons that they have previously created. It also Xdiscovers new and better laws of transformation. As a result, CTK will Xperiodically create a new grand design which is far better than the old. XThe wizards determine when is a good time to implement this new design. XThis is when the tourist season is slow or when no important travelers X(VIPs) are to arrive. The kingdom must be closed for the actual Ximplementation and is leter reopened as a new and better place to go. X XA final question you might ask is what happens when the number of tourists Xbecomes too great for the kingdom to handle in a reasonable period of time X(i.e., the tourist lines at the ports are too long). The Kingdom of XTransformation has three options: (1) shorten the paths that a tourist must Xtravel, or (2) convince CTK to develop a faster breed of horses so that the Xtravelers can finish sooner, or (3) annex more territories so that the Xkingdom can handle more travelers. X XThus ends the story of the Kingdom of Transformation. I hope this has Xexplained my job to you: I slay dragons for a living. X X# X#should do an automatic undivert.. X# SHAR_EOF if test 7873 -ne "`wc -c < 'test.m4'`" then echo shar: error transmitting "'test.m4'" '(should have been 7873 characters)' fi fi # end of overwriting check echo shar: extracting "'README'" if test -f 'README' then echo shar: will not over-write existing file "'README'" else cat << \SHAR_EOF > 'README' What you have here is a completely PD implementation of M4. It was originally written for the GNU project. This version was the last version before a major re-write took place. Pd M4 is based on software tools macro, as described in the two tools books by Kernighan and Plauger. Although some serious changes have been made, this version inherits the basic design problems of the original, hence the ugliness of the underlying code. [GNU version of this processor is re-designed in a much cleaner fashion, and is expected to be out before 1988. GNU version also includes an extensive texinfo document.] PDness: This code *is* PD. You (public) have all the rights to the code. [But this also means you (singular) do not have any *extra* rights to the code, hence it is impossible for you to restrict the use and distribution of this code in any way.] Dedication: This posting is a dedication to an old 750 that started out running 4.1BSD and had 1.5 meg, 1 dz11, and 2 Rk07 drives. It was named yetti [sic] by accident, and was managed by the author until its retirement few months ago. [the name yetti now identifies a different machine] Distribution + misc: The distribution includes a small test suite, the sources and a man page. texinfo document is not included. The makefile is pretty simple. See the makefile for configuration options. Try "make time" for some timing comparisons between your un*x m4 and the pd m4. [It should be slighly slower than V7 m4, and slightly faster than SV m4]. Make sure to set MBIN to indicate the location of un*x m4. See the test suite (test.m4) for some additional comments about pd m4 vs un*x m4. Some thoughts: M4 is a neat macro processor but probably a bit outdated by now. It does not need gratuitous additions, or "features", but a complete re-write. As it stands, it is powerful enough for most macro processing needs. We have, for example, used it to build a configuration language for DECNET under VMS. It can be a handy software engineering tool under most circumstances, and can displace a lot of meaningless little hacks written in C, pascal or whatever. [See some net postings for references.] Suggestions for hacking: If you want to hack M4 further, you may wish to implement the SV m4 "trace" facility, and extended (5-char) Comment/Quote definitions. This version also needs some dynamicity for its data structures, and the ability to handle multiple file names in the command line. If you want to add "features", you may wish to first think about implementing the "feature" as an M4 macro. If you really want to elevate this processor into a more state-of the-art tool, than you should probably re-write it. [But I have already done that, so you may wish to wait for the GNU version to get a head start.] Feedback: If you have any important fixes and/or speed improvements, I am much interested, since my new version inherits some code from this version. I am also interested in hearing about any unique applica- tions of M4. I am not interested in gratuitous hacks or "neat" kitchen-sink features. Contact: Usenet: [decvax|ihnp4]!utzoo!yunexus!oz || ...seismo!mnetor!yunexus!oz Bitnet: oz@[yulibra|yuyetti].BITNET Phonet: [416] 736-5257 x 3976 enjoy. oz SHAR_EOF fi # end of overwriting check echo shar: extracting "'MANIFEST'" '(230 characters)' if test -f 'MANIFEST' then echo shar: will not over-write existing file "'MANIFEST'" else sed 's/^ X//' << \SHAR_EOF > 'MANIFEST' Xmdef.h - definitions and structures Xmain.c - this file: driver routines Xeval.c - general macro evaluator Xserv.c - service routines (doxxxx) Xmisc.c - miscellaneous routines Xexpr.c - expression parser Xlook.c - hash table management SHAR_EOF if test 230 -ne "`wc -c < 'MANIFEST'`" then echo shar: error transmitting "'MANIFEST'" '(should have been 230 characters)' fi fi # end of overwriting check echo shar: extracting "'m4.1'" '(9644 characters)' if test -f 'm4.1' then echo shar: will not over-write existing file "'m4.1'" else sed 's/^ X//' << \SHAR_EOF > 'm4.1' X.TH M4 local "30 Aug 1987" X.DA 08 Jan 1986 X.SH NAME Xpd m4 \- macro processor X.SH ORIGIN XMetaSystems X.SH SYNOPSIS X.BI m4 "[ options ]" X.SH DESCRIPTION X.I Pd M4 Xis a un*x M4 look-alike macro processor Xintended as a front end for Ratfor, Pascal, and other languages that do not Xhave a built-in macro processing capability. XPd M4 reads standard input, the processed text is written on the standard output. X.PP XThe options and their effects are as follows: X.TP X\f3\-D\fP\f2name\^\fP[\f3=\fP\f2val\^\fP] XDefines X.I name Xto X.I val Xor to null in X.IR val 's Xabsence. X.TP X.BI \-U name Xundefines X.IR name . X.PP XMacro calls Xhave the form: X.PP X.RS X\fBname\fI(arg1,arg2, .\|.\|., argn)\fR X.RE X.PP XThe X.B ( Xmust immediately follow the name of the macro. XIf the name of a defined macro is not followed by a X.BR ( , Xit is taken to be a call of that macro with no arguments, i.e. name(). XPotential macro names consist of alphabetic letters and digits. X.PP XLeading unquoted blanks, tabs and newlines are ignored while collecting Xarguments. XLeft and right single quotes are used to quote strings. XThe value of a quoted string is the string stripped of the quotes. X.PP XWhen a macro name is recognized, Xits arguments are collected by searching for a matching X.BR ) . XIf fewer arguments are supplied than are in the macro definition, Xthe trailing arguments are taken to be null. XMacro evaluation proceeds normally during the collection of the arguments, Xand any commas or right parentheses Xwhich happen to turn up within the value of a nested Xcall are as effective as those in the original input text. (This is typically Xreferred as X.I inside-out Xmacro expansion.) XAfter argument collection, Xthe value of the macro is pushed back onto the input stream Xand rescanned. X.PP X.I Pd M4 Xmakes available the following built-in macros. XThey may be redefined, but once this is done the original meaning is lost. XTheir values are null unless otherwise stated. X.de MC X.TP 14 X.B \\$1 Xusage: \\fI\\$1\\$2\\fR X.br X.. X.MC define "(name [, val])" Xthe second argument is installed as the value of the macro Xwhose name is the first argument. If there is no second argument, Xthe value is null. XEach occurrence of X.BI $ n Xin the replacement text, Xwhere X.I n Xis a digit, Xis replaced by the X.IR n -th Xargument. XArgument 0 is the name of the macro; Xmissing arguments are replaced by the null string. X.MC defn "(name [, name ...]) Xreturns the quoted definition of its argument(s). Useful in renaming Xmacros. X.MC undefine "(name [, name ...])" Xremoves the definition of the macro(s) named. If there is Xmore than one definition for the named macro, (due to previous use of X.IR pushdef ) Xall definitions are removed. X.MC pushdef "(name [, val])" Xlike X.IR define , Xbut saves any previous definition by stacking the current definition. X.MC popdef "(name [, name ...])" Xremoves current definition of its argument(s), Xexposing the previous one if any. X.MC ifdef "(name, if-def [, ifnot-def])" Xif the first argument is defined, the value is the second argument, Xotherwise the third. XIf there is no third argument, the value is null. XA word indicating the current operating system is predefined. X(e.g. X.I unix Xor X.IR vms ) X.MC shift "(arg, arg, arg, ...)" Xreturns all but its first argument. XThe other arguments are quoted and pushed back with Xcommas in between. XThe quoting nullifies the effect of the extra scan that Xwill subsequently be performed. X.MC changequote "(lqchar, rqchar)" Xchange quote symbols to the first and second arguments. XWith no arguments, the quotes are reset back to the default Xcharacters. (i.e., \*`\|\*'). X.MC changecom "(lcchar, rcchar)" Xchange left and right comment markers from the default X.B # Xand X.BR newline . XWith no arguments, the comment mechanism is reset back to Xthe default characters. XWith one argument, the left marker becomes the argument and Xthe right marker becomes newline. XWith two arguments, both markers are affected. X.MC divert "(divnum)" X.I m4 Xmaintains 10 output streams, Xnumbered 0-9. initially stream 0 is the current stream. XThe X.I divert Xmacro changes the current output stream to its (digit-string) Xargument. XOutput diverted to a stream other than 0 through 9 Xdisappears into bitbucket. X.MC undivert "([divnum [, divnum ...]])" Xcauses immediate output of text from diversions named as Xargument(s), or all diversions if no argument. XText may be undiverted into another diversion. XUndiverting discards the diverted text. At the end of input processing, X.I M4 Xforces an automatic X.IR undivert , Xunless X.I m4wrap Xis defined. X.MC divnum "()" Xreturns the value of the current output stream. X.MC dnl "()" Xreads and discards characters up to and including the next newline. X.MC ifelse "(arg, arg, if-same [, ifnot-same | arg, arg ...])" Xhas three or more arguments. XIf the first argument is the same string as the second, Xthen the value is the third argument. XIf not, and if there are more than four arguments, the process is Xrepeated with arguments 4, 5, 6 and 7. XOtherwise, the value is either the fourth string, or, if it is not present, Xnull. X.MC incr "(num)" Xreturns the value of its argument incremented by 1. XThe value of the argument is calculated Xby interpreting an initial digit-string as a decimal number. X.MC decr "(num)" Xreturns the value of its argument decremented by 1. X.MC eval "(expression)" Xevaluates its argument as a constant expression, using integer arithmetic. XThe evaluation mechanism is very similar to that of X.I cpp X(#if expression). XThe expression can involve only integer constants and character constants, Xpossibly connected by the binary operators X.nf X.ft B X X* / % + - >> << < > X<= >= == != & ^ | && || X X.ft R X.fi Xor the unary operators \fB\- ~ !\fR Xor by the ternary operator \fB ? : \fR. XParentheses may be used for grouping. Octal numbers may be specified as Xin C. X.MC len "(string)" Xreturns the number of characters in its argument. X.MC index "(search-string, string)" Xreturns the position in its first argument where the second argument Xbegins (zero origin), Xor \-1 if the second argument does not occur. X.MC substr "(string, index [, length])" Xreturns a substring of its first argument. XThe second argument is a zero origin Xnumber selecting the first character (internally treated as an expression); Xthe third argument indicates the length of the substring. XA missing third argument is taken to be large enough to extend to Xthe end of the first string. X.MC translit "(source, from [, to])" Xtransliterates the characters in its first argument Xfrom the set given by the second argument to the set given by the third. XIf the third argument is shorter than the second, all extra characters Xin the second argument are deleted from the first argument. If the third Xargument is missing altogether, all characters in the second argument are Xdeleted from the first argument. X.MC include "(filename)" Xreturns the contents of the file named in the argument. X.MC sinclude "(filename)" Xis identical to X.IR include , Xexcept that it Xsays nothing if the file is inaccessible. X.MC paste "(filename)" Xreturns the contents of the file named in the argument without any Xprocessing, unlike X.IR include. X.MC spaste "(filename)" Xis identical to X.IR paste , Xexcept that it says nothing if the file is inaccessible. X.MC syscmd "(command)" Xexecutes the X.SM UNIX Xcommand given in the first argument. XNo value is returned. X.MC sysval "()" Xis the return code from the last call to X.IR syscmd . X.MC maketemp "(string)" Xfills in a string of X.SM XXXXXX Xin its argument with the current process X.SM ID\*S. X.MC m4exit "([exitcode])" Xcauses immediate exit from X.IR m4 . XArgument 1, if given, is the exit code; Xthe default is 0. X.MC m4wrap "(m4-macro-or-built-in)" Xargument 1 will be pushed back at final X.BR EOF ; Xexample: m4wrap(`dumptable()'). X.MC errprint "(str [, str, str, ...])" Xprints its argument(s) on stderr. If there is more than one argument, Xeach argument is separated by a space during the output. X.MC dumpdef "([name, name, ...])" Xprints current names and definitions, Xfor the named items, or for all if no arguments are given. X.dt X.SH AUTHOR XOzan S. Yigit (oz) X.SH BUGS XPd M4 is distributed at the source level, and does not require an expensive Xlicense agreement. X.PP XA sufficiently complex M4 macro set is about as readable Xas X.BR APL . X.PP XAll complex uses of M4 require the ability to program in deep recursion. XPrevious lisp experience is recommended. X.PP XPd M4 is slower than V7 M4. X.SH EXAMPLES X.PP XThe following macro program illustrates the type of things that Xcan be done with M4. X.PP X.RS X.nf X\fBchangequote\fR(<,>) \fBdefine\fR(HASHVAL,99) \fBdnl\fR X\fBdefine\fR(hash,<\fBexpr\fR(str(\fBsubstr\fR($1,1),0)%HASHVAL)>) \fBdnl\fR X\fBdefine\fR(str, X <\fBifelse\fR($1,",$2, X <str(\fBsubstr\fR(<$1>,1),<\fBexpr\fR($2+'\fBsubstr\fR($1,0,1)')>)>) X >) \fBdnl\fR X\fBdefine\fR(KEYWORD,<$1,hash($1),>) \fBdnl\fR X\fBdefine\fR(TSTART, X<struct prehash { X char *keyword; X int hashval; X} keytab[] = {>) \fBdnl\fR X\fBdefine\fR(TEND,< "",0 X};>) \fBdnl\fR X.fi X.RE X.PP XThus a keyword table containing the keyword string and its pre-calculated Xhash value may be generated thus: X.PP X.RS X.nf XTSTART X KEYWORD("foo") X KEYWORD("bar") X KEYWORD("baz") XTEND X.fi X.RE X.PP Xwhich will expand into: X.RS X.nf Xstruct prehash { X char *keyword; X int hashval; X} keytab[] = { X "foo",27, X "bar",12, X "baz",20, X "",0 X}; X.fi X.RE X.PP XPresumably, such a table would speed up the installation of the Xkeywords into a dynamic hash table. (Note that the above macro Xcannot be used with X.IR M4 , Xsince X.B eval Xdoes not handle character constants.) X X.SH SEE ALSO Xcc(1), Xm4(1), Xcpp(1). X.I "The M4 Macro Processor\^" Xby B. W. Kernighan and D. M. Ritchie. X SHAR_EOF if test 9644 -ne "`wc -c < 'm4.1'`" then echo shar: error transmitting "'m4.1'" '(should have been 9644 characters)' fi fi # end of overwriting check # End of shell archive