table.c

#include <stdio.h>
#include "util.h"
#include "table.h"

#define TABSIZE 127

#ifdef __GNUC__
#pragma GCC diagnostic ignored "-Wpointer-to-int-cast"
#endif

typedef struct binder_* binder;
struct binder_ {
    void *key;
    void *value;
    binder next;
    void* prevtop;
};

struct TAB_table_ {
    binder table[TABSIZE];
    void *top;
};

static binder Binder(void *key, void *value, binder next, void *prevtop) {
    binder b = checked_malloc(sizeof(*b));
    b->key = key;
    b->value = value;
    b->next = next;
    b->prevtop = prevtop;
    return b;
}

TAB_table TAB_empty(void) {
    TAB_table t = checked_malloc(sizeof(*t));
    int i;
    t->top = NULL;
    for(i = 0; i < TABSIZE; i++) {
        t->table[i] = NULL;
    }
    return t;
}

void TAB_enter(TAB_table t, void *key, void* value) {
    int index;
    assert(t && key);
    index = ((unsigned)key) % TABSIZE;
    t->table[index] = Binder(key, value, t->table[index], t->top);
    t->top = key;
}

void* TAB_look(TAB_table t, void* key) {
    int index;
    binder b;
    assert(t);
    assert(key);
    index = ((unsigned) key) % TABSIZE;
    for(b = t->table[index]; b; b=b->next) {
        if (b->key == key) {
            return b->value;
        }
    }
    return NULL;
}

void *TAB_pop(TAB_table t) {
    void *k; 
    binder b;
    int index;
    assert(t);
    k = t->top;
    assert(k);
    index = ((unsigned)k) % TABSIZE;
    b = t->table[index];
    assert(b);
    t->table[index] = b->next;
    t->top = b->prevtop;
    return b->key;
}

void TAB_dump(TAB_table t, void (*show)(void* key, void* value)) {
    void* k = t->top;
    int index = ((unsigned)k) % TABSIZE;
    binder b = t->table[index];
    if(b == NULL) return;
    t->table[index] = b->next;
    t->top = b->prevtop;
    show(b->key, b->value);
    TAB_dump(t, show);
    assert(t->top == b->prevtop && t->table[index] == b->next);\
    t->top = k;
    t->table[index] = b;
}