adding the rest of vern's files

examples/README

@@ -0,0 +1,15 @@
+This directory contains some examples of what you can do with
+flex. These files are not tested regularly so you might have to tinker
+a bit before they work for you. Updates, new files and patches are welcome.
+
+	- debflex.awk, an awk script for anotating flex debug output.
+	  It presently only works with gawk and mawk, not with "old"
+	  or "new" awk.
+
+	- testxxLexer.l, a sample C++ program that uses flex's scanner
+	  class option ("-+").
+
+	- fastwc/, a subdirectory containing examples of how to use flex
+	  to write progressively higher-performance versions of the Unix
+	  "wc" utility.  This certainly should work with 2.5, but hasn't
+	  been tested.

examples/debflex.awk

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+# Clarify the flex debug trace by substituting first line of each rule.
+# Francois Pinard <[email protected]>, July 1990.
+#
+# Rewritten to process correctly \n's in scanner input.
+# BEGIN section modified to correct a collection of rules.
+# Michal Jaegermann <[email protected]>, December 1993
+#
+# Sample usage:
+#	flex -d PROGRAM.l
+#	gcc -o PROGRAM PROGRAM.c -lfl
+#	PROGRAM 2>&1 | gawk -f debflex.awk PROGRAM.l
+#
+# (VP's note: this script presently does not work with either "old" or
+#  "new" awk; fixes so it does will be welcome)
+
+BEGIN {
+    # Insure proper usage.
+
+    if (ARGC != 2) {
+	print "usage: gawk -f debflex.awk FLEX_SOURCE <DEBUG_OUTPUT";
+	exit (1);
+    }
+
+    # Remove and save the name of flex source.
+
+    source = ARGV[1];
+    ARGC--;
+
+    # Swallow the flex source file.
+
+    line = 0;
+    section = 1;
+    while (getline <source) {
+
+	# Count the lines.
+
+	line++;
+
+	# Count the sections.  When encountering section 3,
+	# break out of the awk BEGIN block.
+
+	if (match ($0, /^%%/)) {
+	    section++;
+	    if (section == 3) {
+		break;
+	    }
+	}
+	else {
+	    # Only the lines in section 2 which do not begin in a
+	    # tab or space might be referred to by the flex debug
+	    # trace.  Save only those lines.
+
+	    if (section == 2 && match ($0, /^[^ \t]/)) {
+		rules[line] = $0;
+	    }
+	}
+    }
+    dashes = "-----------------------------------------------------------";
+    collect = "";
+    line = 0;
+}
+
+# collect complete rule output from a scanner
+$0 !~ /^--/ {
+    collect = collect "\n" $0;
+    next;
+}
+# otherwise we have a new rule - process what we got so far
+{
+    process();
+}
+# and the same thing if we hit EOF
+END {
+    process();
+}
+
+function process() {
+
+    # splitting this way we loose some double dashes and
+    # left parentheses from echoed input - a small price to pay
+    n = split(collect, field, "\n--|[(]");
+
+    # this loop kicks in only when we already collected something
+    for (i = 1; i <= n; i++) {
+	if (0 != line) {
+	    # we do not care for traces of newlines.
+	    if (0 == match(field[i], /\"\n+\"[)]/)) {
+		if (rules[line]) {
+		    text = field[i];
+		    while ( ++i <= n) {
+			text = text field[i];
+		    }
+		    printf("%s:%d: %-8s -- %s\n",
+			   source, line, text, rules[line]);
+		}
+		else {
+		    print;
+		    printf "%s:%d: *** No such rule.\n", source, line;
+		}
+	    }
+	    line = 0;
+	    break;
+	}
+	if ("" != field[i]) {
+	    if ("end of buffer or a NUL)" == field[i]) {
+		print dashes;  # Simplify trace of buffer reloads
+		continue;
+	    }
+	    if (match(field[i], /accepting rule at line /)) {
+		# force interpretation of line as a number
+		line = 0 + substr(field[i], RLENGTH);
+		continue;
+	    }
+	    # echo everything else
+	    printf("--%s\n", field[i]);
+	}
+    }
+    collect = "\n" $0;  # ... and start next trace
+}

examples/manual/ChangeLog

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+Tue Oct  5 21:51:59 1993  Vern Paxson
+
+	* Removed FILTER/ subdirectory.
+
+	* Removed alloca.c.
+
+	* Changed Makefile definition of CC to just "gcc -g", removed
+	  assumption of alloca being present.
+
+	* Added pointer to MISC/fastwc/ to wc.lex.
+
+Tue Jun  8 15:47:39 1993  Gavin Thomas Nicol  (nick at sillybugs)
+
+	* Changed main() in wc.lex extensively. The old version would not
+	  work correctly without the YY_NEW_FILE. (lex handles the older
+	  version OK though).
+
+	* Added a rule to expr.lex to handle whitespace. The old version
+ 	  reported an illegal character.
+
+	* Added -traditional to the gcc flags because the flex definition
+	  for free() clashes with some systems that have old header files.
+
+

examples/manual/Makefile

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+#############################################################
+#
+# Makefile     : Makefile for Flex examples.
+# Author       : G.T.Nicol
+# Last Updated : 1993/10/05
+#
+# If you use bison, you may have to supply an alloca
+#
+#############################################################
+
+CC       = gcc -g
+LEX      = flex -i -I 
+YACC     = bison -d -y
+ALLOCA   =
+
+############################################################
+#
+# DO NOT CHANGE ANYTHING FROM HERE ON !!!!!!!!! 
+#
+############################################################
+
+all: expr front myname eof wc replace user_act string1\
+     string2 yymore numbers dates cat
+
+expr:   expr.y expr.lex
+	$(YACC) expr.y
+	$(LEX)  expr.lex
+	$(CC) -o expr lex.yy.c y.tab.c $(ALLOCA) -ll -lm
+
+front:  front.y front.lex
+	$(YACC) front.y
+	$(LEX)  front.lex
+	$(CC) -o front lex.yy.c y.tab.c $(ALLOCA) -ll -lm
+
+numbers: numbers.lex
+	$(LEX)  numbers.lex
+	$(CC)   lex.yy.c -o numbers
+
+dates: dates.lex
+	$(LEX)  dates.lex
+	$(CC)   lex.yy.c -o dates -ll
+
+yymore: yymore.lex
+	$(LEX)  yymore.lex
+	$(CC)   lex.yy.c -o yymore -ll
+
+string1: string1.lex
+	$(LEX)  string1.lex
+	$(CC)   lex.yy.c -o string1 -ll
+
+string2: string2.lex
+	$(LEX)  string2.lex
+	$(CC)   lex.yy.c -o string2 -ll
+
+myname: myname.lex
+	$(LEX)  myname.lex
+	$(CC)   lex.yy.c -o myname -ll
+
+myname2: myname2.lex
+	$(LEX)  myname2.lex
+	$(CC)   lex.yy.c -o myname2 -ll
+
+eof:    eof_rules.lex
+	$(LEX)  eof_rules.lex
+	$(CC)   lex.yy.c -o eof -ll
+
+wc:     wc.lex
+	$(LEX)  wc.lex
+	$(CC)   lex.yy.c -o wc -ll
+
+cat:    cat.lex
+	$(LEX)  cat.lex
+	$(CC)   lex.yy.c -o cat -ll
+
+replace: replace.lex
+	$(LEX)  replace.lex
+	$(CC)   lex.yy.c -o replace -ll
+
+user_act: expr.y expr.lex
+	$(LEX)  user_act.lex
+	$(CC) -o user_act lex.yy.c -ll 
+
+clean:
+	rm -f *.BAK *.o core *~* *.a 
+	rm -f *.tab.h *.tab.c
+	rm -f myname expr lex.yy.c *.out eof wc yymore
+	rm -f replace front user_act string1 string2
+	rm -f dates numbers cat

examples/manual/README

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+This directory contains the example programs from the manual, and a few 
+other things as well. To make all the programs, simply type "make",
+and assuming you have flex and gcc, all will be well.
+
+To build the programs individually, type
+
+   make program_name
+
+For example:
+
+   make expr
+
+
+The subdirectory FILTER contains a collection of the silly filters
+that have appeared on the Internet over the years. The author of the
+flex manual has included them for fun, but does not guarantee they will
+work with flex, or even work at all.

examples/manual/cat.lex

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+/*
+ * cat.lex: A demonstration of YY_NEW_FILE.
+ */
+
+%{
+#include <stdio.h>
+
+char **names = NULL;
+int  current = 1;
+%}
+
+%%
+<<EOF>> {
+           current += 1;
+           if(names[current] != NULL){
+              yyin = fopen(names[current],"r");
+              if(yyin == NULL){
+                fprintf(stderr,"cat: unable to open %s\n",
+                        names[current]);
+                yyterminate();
+              }
+              YY_NEW_FILE;
+           } else {
+             yyterminate();
+           }
+        }
+%%
+
+int main(int argc, char **argv)
+{
+    if(argc < 2){
+       fprintf(stderr,"Usage: cat files....\n");
+       exit(1);
+    }
+    names = argv;
+
+    yyin = fopen(names[current],"r");
+    if(yyin == NULL){
+      fprintf(stderr,"cat: unable to open %s\n",
+              names[current]);
+      yyterminate();
+    }
+
+    yylex();
+}