symbol.c

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

struct S_symbol_ { string name; S_symbol next; };

static S_symbol mksymbol(string name, S_symbol next) {
    S_symbol s = checked_malloc(sizeof(*s));
    s->name = name;
    s->next = next;
    return s;
}

#define SIZE 109

static S_symbol hashtable[SIZE];

static unsigned int hash(char* s0) {
    unsigned int h = 0;
    char* s;
    for(s = s0; *s; s++) {
        h = h * 65599 + *s;
    }
    return h;
}

static int streq(string a, string b) {
    return !strcmp(a, b);
}

S_symbol S_Symbol(string name) {
    int index = hash(name) % SIZE;
    S_symbol syms = hashtable[index], sym;
    for(sym = syms; sym; sym = sym->next) {
        if(streq(sym->name, name)) return sym;
    }
    sym = mksymbol(name, syms);
    hashtable[index]=sym;
    return sym;
}

string S_name(S_symbol sym) {
    return sym->name;
}

S_table S_empty(void) {
    return TAB_empty();
}

void S_enter(S_table t, S_symbol sym, void* value) {
    TAB_enter(t, sym, value);
}

void *S_look(S_table t, S_symbol sym) {
    return TAB_look(t, sym);
}

static struct S_symbol_ marksym = { "<mark>", 0};

void S_beginScope(S_table t) {
    S_enter(t, &marksym, NULL);
}

void S_endScope(S_table t) {
    S_symbol s;
    do {
        s = TAB_pop(t);
    } while(s != &marksym);
}

void S_dump(S_table t, void (*show)(S_symbol sym, void* bindng)) {
    TAB_dump(t, (void (*)(void*, void*)) show);
}