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%{
#include <stdlib.h>
#include "token.h"
extern int yycolumn, yylength, yyline, yylval;
extern char *stringTable;
extern int stringTableIndices[];
extern int nStringsStored;
extern int nCharsStored;
/* functions */
void ReportError(char *, int, int);
int getStrTableIndex(char *, int, int);
void RemoveQuotes(char *);
%}
/* regular definitions */
id ([a-zA-Z])+
delim [ \t]
ws {delim}+
newline [\n]
%%
{newline} {yyline++; yycolumn=0;}
{ws} {yycolumn+=yyleng;}
"/*"([^*]|[ \t\n]|(\*+([^*/]|[ \t\n])))* {ReportError("comment doesn't terminate",yyline,yycolumn);}
"/*"([^*]|[ \t\n]|(\*+([^*/]|[ \t\n])))*"*"+"/" {yycolumn+=yyleng;};
"&&" {yycolumn+=yyleng; return (ANDnum);}
":=" {yycolumn+=yyleng; return (ASSGNnum);}
[dD][eE][cC][lL][aA][rR][aA][tT][iI][oO][nN][sS] {yycolumn+=yyleng; return (DECLARATIONSnum);}
"." {yycolumn+=yyleng; return (DOTnum);}
[eE][nN][dD][dD][eE][cC][lL][aA][rR][aA][tT][iI][oO][nN][sS] {yycolumn+=yyleng; return (ENDDECLARATIONSnum);}
"=" {yycolumn+=yyleng; return (EQUALnum);}
">" {yycolumn+=yyleng; return (GTnum);}
[iI][nN][tT] {yycolumn+=yyleng; return (INTnum);}
"[" {yycolumn+=yyleng; return (LBRACnum);}
"(" {yycolumn+=yyleng; return (LPARENnum);}
[mM][eE][tT][hH][oO][dD] {yycolumn+=yyleng; return (METHODnum);}
"!=" {yycolumn+=yyleng; return (NEnum);}
"||" {yycolumn+=yyleng; return (ORnum);}
[pP][rR][oO][gG][rR][aA][mM] {yycolumn+=yyleng; return (PROGRAMnum);}
"]" {yycolumn+=yyleng; return (RBRACnum);}
")" {yycolumn+=yyleng; return (RPARENnum);}
";" {yycolumn+=yyleng; return (SEMInum);}
[vV][aA][lL] {yycolumn+=yyleng; return (VALnum);}
[wW][hH][iI][lL][eE] {yycolumn+=yyleng; return (WHILEnum);}
[cC][lL][aA][sS][sS] {yycolumn+=yyleng; return (CLASSnum);}
"," {yycolumn+=yyleng; return (COMMAnum);}
"/" {yycolumn+=yyleng; return (DIVIDEnum);}
[eE][lL][sS][eE] {yycolumn+=yyleng; return (ELSEnum);}
"==" {yycolumn+=yyleng; return (EQnum);}
">=" {yycolumn+=yyleng; return (GEnum);}
[iI][fF] {yycolumn+=yyleng; return (IFnum);}
"{" {yycolumn+=yyleng; return (LBRACEnum);}
"<=" {yycolumn+=yyleng; return (LEnum);}
"<" {yycolumn+=yyleng; return (LTnum);}
"-" {yycolumn+=yyleng; return (MINUSnum);}
"!" {yycolumn+=yyleng; return (NOTnum);}
"+" {yycolumn+=yyleng; return (PLUSnum);}
"}" {yycolumn+=yyleng; return (RBRACEnum);}
[rR][eE][tT][uU][rR][nN] {yycolumn+=yyleng; return (RETURNnum);}
"*" {yycolumn+=yyleng; return (TIMESnum);}
[vV][oO][iI][dD] {yycolumn+=yyleng; return (VOIDnum);}
'(.|[ \t])*' {RemoveQuotes(yytext); yylval = getStrTableIndex(yytext,yyline,yycolumn); yycolumn+=yyleng; return (SCONSTnum);}
'(.|[ \t\n])*' {ReportError("string constant crosses line boundary",yyline,yycolumn); yyline++; yycolumn=0;}
[1-9][0-9]* {yylval = atoi(yytext); yycolumn+=yyleng; return (ICONSTnum);}
[0-9][a-zA-Z0-9]* {ReportError("identifier starting with a digit",yyline,yycolumn); yycolumn+=yyleng;}
[a-zA-Z][a-zA-Z0-9]* {yylval = getStrTableIndex(yytext,yyline,yycolumn); yycolumn+=yyleng; return (IDnum);}
%%
void ReportError(char *message,int line, int column) {
fprintf( stderr, "\nError at line %d, column %d (first char): %s\n\n", line, column, message);
return;
}
int getStrTableIndex(char *string, int line, int column) {
int i;
/* use index array to search table for string*/
for (i=0; i < nStringsStored; i++) {
/* return index if found */
if (strcmp(string, stringTable + stringTableIndices[i]) == 0) {
return stringTableIndices[i];
}
}
/* error if string table is full */
if (nStringsStored == LIMIT1) {
ReportError("can't add string to string table: max character count.",line, column);
return -1;
}
/* error if index table is full */
if (nStringsStored == LIMIT2) {
ReportError("can't add string to string table: max number of unique strings",line, column);
return -1;
}
/* add string to table if not full and return index */
stringTableIndices[i] = nCharsStored;
memcpy(stringTable + stringTableIndices[i],string,strlen(string)+1);
nCharsStored+=strlen(string)+1;
nStringsStored++;
return stringTableIndices[i];
}
/* this lexer detects string constants by their quotes, so yytext includes them
* even though they aren't really part of the string
* so this removes them */
void RemoveQuotes(char *string) {
memmove(string, string+1, strlen(string));
string[strlen(string) - 1] = '\0';
return;
}
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