object.c

//
// Created by Fabian Simon on 03.10.23.
//

#include <stdio.h>
#include <string.h>

#include "memory.h"
#include "object.h"
#include "value.h"
#include "vm.h"
#include "table.h"

#define ALLOCATE_OBJ(type, object_type) \
    (type*)allocate_object(sizeof(type), object_type)


static Obj* allocate_object(size_t size, ObjType type) {
    Obj* object = (Obj*) reallocate(NULL, 0, size);
    object->type = type;
    object->next = vm.objects;
    vm.objects = object;

    return object;
}

ObjFunction* new_function() {
    ObjFunction* function = ALLOCATE_OBJ(ObjFunction, OBJ_FUNCTION);
    function->arity = 0;
    function->name = NULL;
    init_chunk(&function->chunk);
    return function;
}

static ObjString* allocate_string(char* chars, int length, uint32_t hash) {
    ObjString* string = ALLOCATE_OBJ(ObjString, OBJ_STRING);
    string->length = length;
    string->chars = chars;
    string->hash = hash;
    table_set(&vm.strings, string, NIL_VAL);
    return string;
}

static uint32_t hash_string(const char* key, int length) {
    uint32_t hash = 2166136261u;
    for (int i = 0; i < length; i++) {
        hash ^= (uint8_t) key[i];
        hash *= 16777619;
    }
    return hash;
}

ObjString* take_string(const char* chars, int length) {
    uint32_t hash = hash_string(chars, length);
    ObjString* interned = table_find_string(&vm.strings, chars, length, hash);

    if (interned != NULL) {
        FREE_ARRAY(char, chars, length+1);
        return interned;
    }

    return allocate_string(chars, length, hash);
}

ObjString* copy_string(const char* chars, int length) {
    uint32_t hash = hash_string(chars, length);
    ObjString* interned = table_find_string(&vm.strings, chars, length, hash);

    if (interned != NULL) return interned;

    char* heap_chars = ALLOCATE(char, length + 1);
    memcpy(heap_chars, chars, length);
    heap_chars[length] = '\0';
    return allocate_string(heap_chars, length, hash);
}

static void print_function(ObjFunction* function) {
    if (function->name == NULL) {
        printf("<script>");
        return;
    }

    printf("<fn %s", function->name->chars);
}

void print_object(Value val) {
    switch (OBJ_TYPE(val)) {
        case OBJ_FUNCTION:
            print_function(AS_FUNCTION(val));
        case OBJ_STRING:
            printf("%s", AS_CSTRING(val));
            break;
    }
}