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#include "parse.h"
#include "tokens.h"
#include "list.h"
#include "atom.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
void print_list(struct list *list, int level)
{
while (list)
{
struct atom *atom = LIST_GET_ATOM(list);
if (IS_TRUE(list))
{
printf("#t");
}
else if (IS_FALSE(list))
{
printf("#f");
}
else if (IS_NIL(list))
{
printf("nil");
}
else
{
switch (atom->type)
{
case ATOM_SYMBOL:
printf("%.*s", atom->str.len, atom->str.str);
break;
case ATOM_LIST:
printf("(");
print_list(atom->list, level+1);
printf(")");
break;
case ATOM_STR:
printf("\"%.*s\"", atom->str.len, atom->str.str);
break;
case ATOM_INT:
printf("%ld", atom->l);
}
}
if (list->next)
printf(" ");
list = list->next;
}
if (level == 0)
printf("\n");
}
int parse_next(const char *src, int *pos, struct atom **result)
{
struct token token;
int rc;
if ((rc = get_next_token(src, pos, &token)) > 0)
{
switch (token.type)
{
case TOKEN_INT:
*result = atom_new_int(strtol(token.s, NULL, 10));
break;
case TOKEN_STR:
*result = atom_new_str(token.s, token.len);
break;
case TOKEN_SYMBOL:
if (strncmp(token.s, "#t", 2) == 0)
*result = &true_atom;
else if (strncmp(token.s, "#f", 2) == 0)
*result = &false_atom;
else
*result = atom_new_sym(token.s, token.len);
break;
case TOKEN_LPAREN:
{
struct list *l = parse(src, pos);
*result = atom_new_list(l);
break;
}
case TOKEN_RPAREN:
return -2;
case TOKEN_QUOTE:
{
struct atom *quoted = NULL;
parse_next(src, pos, "ed);
struct list *qlist = list_append(NULL,
atom_new_sym("quote", 5));
list_append(qlist, quoted);
*result = atom_new_list(qlist);
break;
}
}
}
return rc;
}
struct list *parse(const char *src, int *pos)
{
int rc;
struct atom *atom;
struct list root, *last = &root;
list_init(last);
while ((rc = parse_next(src, pos, &atom)))
{
if (rc < 0)
break;
last = list_append(last, atom);
}
if (rc < 0 && rc != -2)
return NULL;
return root.next;
}
#ifdef BUILD_TEST
#include "test_util.h"
static const char *test_src_fact =
"(define fact\n"
" ;; Factorial function\n"
" (lambda (n)\n"
" (if (eq n 0)\n"
" 1 ; Factorial of 0 is 1\n"
" (* n (fact (- n 1))))))\n"
"(fact 5) ;; this should evaluate to 120\n";
#define ASSERT_SYM(LIST, SYM) \
ASSERT_TRUE(IS_SYM(LIST)); \
ASSERT_STREQ(SYM, LIST_GET_ATOM(LIST)->str.str)
TEST(test_parse)
{
int pos = 0;
struct list *list;
list = parse(test_src_fact, &pos);
ASSERT_TRUE(list != NULL);
ASSERT_TRUE(IS_LIST(list));
list = LIST_GET_ATOM(list)->list;
ASSERT_TRUE(list != NULL);
ASSERT_SYM(list, "define");
list = list->next;
ASSERT_TRUE(list != NULL);
ASSERT_SYM(list, "fact");
list = list->next;
ASSERT_TRUE(list != NULL);
}
#endif
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