package symbol

import "core:mem"
import "core:strings"

Id :: distinct u32

INVALID :: Id(0)

Table :: struct {
	items:        [dynamic]string,
	lookup:       map[string]Id,
	stored_bytes: int,
	allocator:    mem.Allocator,
}

init_table :: proc(allocator := context.allocator) -> Table {
	table: Table
	table.items.allocator = allocator
	table.lookup.allocator = allocator
	table.allocator = allocator
	return table
}

destroy_table :: proc(table: ^Table) {
	delete(table.lookup)
	for item in table.items {
		delete(item, table.allocator)
	}
	delete(table.items)
}

intern :: proc(table: ^Table, text: string) -> Id {
	if len(text) == 0 {
		return INVALID
	}
	if id, ok := table.lookup[text]; ok {
		return id
	}
	cloned := strings.clone(text, table.allocator)
	id := Id(len(table.items) + 1)
	append(&table.items, cloned)
	table.lookup[cloned] = id
	table.stored_bytes += len(cloned)
	return id
}

resolve :: proc(table: ^Table, id: Id) -> string {
	index := int(id) - 1
	if index < 0 || index >= len(table.items) {
		return ""
	}
	return table.items[index]
}

is_valid :: proc(id: Id) -> bool {
	return id != INVALID
}