symbol.c

#include "global.h"

#define STRMAX 999 /* size of lexemes array */
#define SYMMAX 100 /* size of symtable */
char lexemes [STRMAX];
int lastchar = -1; /*last used position in lexemes */
struct entry symtable[SYMMAX];
int lastentry = 0; /* last used position in symtable */

int lookup(s)  /* returns position of entry for s */
    char s[];
{
    int p;
    for (p = lastentry; p > 0; p = p - 1)
        if (strcmp( symtable[p].lexptr, s) == 0)
            return p;
    return 0;
}
int insert(s, tok) /* returns position of entry for s */
    char s[];
    int tok;
{
    int len;
    len = strlen(s); /* strlen computes length of s */
    if (lastentry + 1 >= SYMMAX)
        error("symbol table full");
    if (lastchar + len + 1 >= STRMAX)
        error("lexemes array full");
    lastentry = lastentry + 1;
    symtable[lastentry].token = tok;
    symtable[lastentry].lexptr = &lexemes[lastchar + 1];
    lastchar = lastchar + len + 1;
    strcpy(symtable[lastentry].lexptr, s);
    return lastentry;
}