SBSPSS/Utils/Parser Generator/SOURCE/yycflex.cpp

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2000-12-08 21:40:33 +01:00
/************************************************************
yycflex.cpp
This file can be freely modified for the generation of
custom code.
Copyright (c) 1999 Bumble-Bee Software Ltd.
************************************************************/
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <limits.h>
#include "clex.h"
int yyflexer::yylex()
{
while (1) {
int state = 1 + yystart;
if (yyeol) {
state++;
}
// yymore
if (yymoreflg) {
yymoreflg = 0; // clear flag
}
else {
yyleng = 0;
yyoldeol = yyeol;
}
int oldleng = yyleng;
// look for a string
do {
// get input character (look ahead character)
int ch = yyinput();
yyassert(ch >= 0 && ch <= UCHAR_MAX || ch == EOF);
if (ch == EOF) {
break;
}
// check for possible overflow
if (yyleng == yytext_size) {
do {
if (yytextgrow) {
if (yytext_size != 0) {
int size = yytext_size * 2;
if (size / 2 == yytext_size) { // overflow check
if (yysettextsize(size)) {
break;
}
}
}
else {
if (yysettextsize(100)) {
break;
}
}
}
yytextoverflow();
exit(EXIT_FAILURE);
}
while (0);
}
// look for a transition
do {
int index = yystate[state].base + ch;
if (index >= 0 && index < yytransitionmax) {
if (yytransition[index].check == state) {
state = yytransition[index].next;
break; // found a transition
}
}
state = yystate[state].def;
if (state < 0) {
if (ch >= 0 && ch <= 0xff) {
state = -state;
}
else {
state = 0;
}
break; // default transition
}
}
while (state != 0);
int leng = yyleng; // slightly more efficient
yytext[leng] = (char)ch;
yystatebuf[leng] = state;
leng++;
yyleng = leng;
}
while (state != 0 && (yystate[state].def != 0 || yystate[state].base != 0));
// now find a match
if (yyleng > oldleng) {
int rejectmatch = 0;
while (1) {
int match = yystate[yystatebuf[yyleng - 1]].match;
if (rejectmatch != 0) {
if (match < 0) {
int index = -match;
do {
match = yymatch[index++];
}
while (match > 0 && match <= rejectmatch);
}
else {
if (match == rejectmatch) {
match = 0;
}
}
rejectmatch = 0;
}
else {
if (match < 0) {
match = yymatch[-match];
}
}
if (match > 0) {
// check for backup
if (yybackup[match]) {
while (yyleng > oldleng) {
int index = yystate[yystatebuf[yyleng - 1]].match;
if (index < 0) {
if (yyback(&yymatch[-index], -match)) {
break; // found an expression
}
}
yyleng--;
yyunput((unsigned char)yytext[yyleng]);
}
}
yytext[yyleng] = '\0';
#ifdef YYDEBUG
yydmatch(match);
#endif
yyrejectflg = 0; // clear flag
int rejectleng = yyleng;
if (yyleng > 0) {
yyeol = (unsigned char)(yytext[yyleng - 1] == '\n');
}
else {
yyeol = yyoldeol;
}
// perform user action
int token = yyaction(match);
if (yyreturnflg) {
return token;
}
if (!yyrejectflg) {
break;
}
if (rejectleng == yyleng) {
rejectmatch = match;
}
}
else if (yyleng > oldleng + 1) {
yyleng--;
yyunput((unsigned char)yytext[yyleng]);
}
else {
yyeol = (unsigned char)(yytext[0] == '\n');
yyoutput(yytext[0]); // non-matched character
break;
}
}
}
else {
yyassert(yyleng == oldleng);
// handles <<EOF>> rules
int index = 0;
int match = yystate[state].match;
if (match < 0) {
index = -match;
match = yymatch[index++];
}
while (match > 0) {
yytext[yyleng] = '\0';
#ifdef YYDEBUG
yydmatch(match);
#endif
yyrejectflg = 0; // clear flag
// perform user action
int token = yyaction(match);
if (yyreturnflg) {
return token;
}
if (!yyrejectflg) {
break;
}
if (index == 0) {
break;
}
match = yymatch[index++];
}
if (yywrap()) {
yyoldeol = 1;
yyeol = 1;
yystart = 0;
return 0; // eof reached
}
}
}
}