1 #include <stdio.h>

2 #include <stdlib.h>

3 #include <string.h>

4 #include "sym.h"

5 #include "rbtree.h"

6

7 struct symbol {

8 char *name;

9 int id, arity;

10 };

11

12 static void del_func(struct rbnode *node, void *cls);

13

14 struct rbtree *symbols;

15

16 int init_sym(void)

17 {

18 if(!(symbols = rb_create(RB_KEY_STRING))) {

19 fprintf(stderr, "failed to create symbol table\n");

20 return -1;

21 }

22 rb_set_delete_func(symbols, del_func, 0);

23 return 0;

24 }

25

26 void destroy_sym(void)

27 {

28 rb_free(symbols);

29 }

30

31 int add_sym(const char *name, int id, int arity)

32 {

33 struct symbol *sym;

34

35 if(!(sym = malloc(sizeof *sym)) || !(sym->name = malloc(strlen(name) + 1))) {

36 perror("failed to allocate symbol");

37 free(sym);

38 return -1;

39 }

40 strcpy(sym->name, name);

41 sym->id = id;

42 sym->arity = arity;

43

44 return rb_insert(symbols, sym->name, sym);

45 }

46

47 int sym_lookup(const char *str)

48 {

49 struct rbnode *node;

50

51 if(!(node = rb_find(symbols, (char*)str))) {

52 fprintf(stderr, "undefined symbol: %s\n", str);

53 return -1;

54 }

55 return ((struct symbol*)node->data)->id;

56 }

57

58 int sym_arity(const char *str)

59 {

60 struct rbnode *node;

61

62 if(!(node = rb_find(symbols, (char*)str))) {

63 fprintf(stderr, "undefined symbol: %s\n", str);

64 return -1;

65 }

66 return ((struct symbol*)node->data)->arity;

67 }

68

69 static void del_func(struct rbnode *node, void *cls)

70 {

71 free(((struct symbol*)node->data)->name);

72 free(node->data);

73 }