parse.c

来自「这是一个C的源代码」· C语言 代码 · 共 85 行

#include <assert.h>
#include <stdio.h> //for EOF
#include <string.h> //strchr
#include <stdlib.h> //for pbc_malloc, pbc_free
#include "pbc_fops.h"
#include "pbc_parse.h"
#include "pbc_tracker.h"
#include "pbc_memory.h"

void 
token_get_generic (token_t tok, fetch_ops_t fops, void *ctx)
{
  assert (fops);
  assert (ctx);
   char *buf;
   int n = 32;
   int i;
   int c;

skipwhitespace:
   for (;;) {
   c = fops->fops_getc (ctx);
   if (c == EOF) {
       tok->type = token_eof;
       return;
   }
   if (!strchr(" \t\r\n", c)) break;
   }

   if (c == '#') {
   for(;;) {
       c = fops->fops_getc (ctx);
       if (c == EOF) {
       tok->type = token_eof;
       return;
       }
       if (c == '\n') break;
   }
   goto skipwhitespace;
   }

   if (c == '<') {
   c = fops->fops_getc (ctx);
   if (c == '/') {
       tok->type = token_langleslash;
       return;
   }
   fops->fops_ungetc (c, ctx);
   tok->type = token_langle;
   return;
   } else if (c == '>') {
   tok->type = token_rangle;
   return;
   } else {
   tok->type = token_word;
   pbc_free(tok->s);
   buf = (char *) pbc_malloc(n);
   i = 0;
   for (;;) {
       buf[i] = c;
       i++;
       if (i == n) {
       n += 32;
       buf = (char *) pbc_realloc(buf, n);
       }
       c = fops->fops_getc(ctx);
       if (c == EOF || strchr(" \t\r\n</>", c)) break;
   }
   buf[i] = 0;
   fops->fops_ungetc(c, ctx);
   tok->s = buf;
   }
}

void token_init(token_t tok)
{
    tok->type = token_none;
    tok->s = NULL;
}

void token_clear(token_t tok)
{
    pbc_free(tok->s);
}