begriffs open source - sa-parse/blob - src/lisp_driver.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 #define YYSTYPE LISPSTYPE
   5 #include "lisp.tab.h"
   6 #include "lisp.lex.h"
   7
   8 void sexpr_print(struct sexpr* s, unsigned depth)
   9 {
  10         for (unsigned i = 0; i < depth; i++)
  11                 printf("  ");
  12         switch (s->type)
  13         {
  14                 case SEXPR_ID:
  15                         puts(s->value.id);
  16                         break;
  17                 case SEXPR_NUM:
  18                         printf("%d\n", s->value.num);
  19                         break;
  20                 case SEXPR_PAIR:
  21                         puts(".");
  22                         sexpr_print(s->left, depth+1);
  23                         sexpr_print(s->right, depth+1);
  24                         break;
  25                 case SEXPR_NIL:
  26                         puts("()");
  27                         break;
  28                 default:
  29                         abort();
  30         }
  31 }
  32
  33 int main(void)
  34 {
  35         int i;
  36         struct sexpr *expr;
  37         yyscan_t scanner;
  38
  39         if ((i = lisplex_init(&scanner)) != 0)
  40                 exit(i);
  41
  42         int e = lispparse(&expr, scanner);
  43         printf("Code = %d\n", e);
  44         if (e == 0 /* success */)
  45         {
  46                 sexpr_print(expr, 0);
  47                 sexpr_free(expr);
  48         }
  49
  50         lisplex_destroy(scanner);
  51         return 0;
  52 }