Example for how to return a string?

[binoculars]

Hi, I'm having trouble returning a string / []const u8. Can you provide an example?

[jjrv]

Currently this is easy in wasm:

const std = @import("std");
const zbind = @import("zbind");

const API = struct {
	pub fn get_allocator() std.mem.Allocator {
		return std.heap.page_allocator;
	}

	pub fn concat(allocator: std.mem.Allocator, a: []const u8, b: []const u8) []const u8 {
		return std.fmt.allocPrint(allocator, "{s}{s}", .{a, b}) catch @panic("OOM");
	}
};

pub fn main() void {}

comptime {
	zbind.init(API);
}

import { get_allocator, concat } from './test';

console.log(concat(get_allocator(), 'abc', 'def').toString());

However on Node it'd need to copy the memory to JS heap. The current slice it returns can be passed to another Zig function, but the memory isn't readable by JS. Haven't decided the semantics yet, how to handle passing slices between called functions quickly without copying, versus passing between languages. Maybe zbind should provide an allocator that allocates in the JS heap, which both can then access quickly.