Zig ULID

See ULID spec for more information about ULIDs.

This implements some functions for working with ULIDs in zig. You can use it by copying ulid.zig to your source code, or by adding it as a zigmod dependency:

- type: git
  path: https://github.com/leroycep/zig-ulid

Developed with Zig version 0.8.0-dev.1028+287f640cc.

Based on ulid-rs by dylanhart.

• now
• encodeBase32
• decodeBase32
• cmp
• eq
• MonotonicFactory

fn now() ulid

Generates a ulid using std.time.milliTimestamp() and the thread-local cryptographic psuedo random number generator.

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

pub fn main() void {
    const generated_ulid = ulid.encode();
    std.log.info("Generated ulid: {s}", .{generated_ulid.encodeBase32()});
}

fn encodeBase32(ulid) [26]u8

Converts a ulid to it's base32 encoding.

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

test "encode" {
    const value = ulid.fromBytes([1]u8{ 0x41 } ** 16);
    const encoded = ulid.encodeBase32(value);
    std.testing.expectEqualStrings("21850M2GA1850M2GA1850M2GA1", &encoded);
}

fn decodeBase32([]u8) !ulid

Parses a base32 encoded ULID.

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

test "decode" {
    const string = "21850M2GA1850M2GA1850M2GA1";
    const decoded = try ulid.decodeBase32(string);
    std.testing.expectEqualStrings(&([1]u8{ 0x41 } ** 16), &decoded);
}

fn cmp(ulid, ulid) std.math.Order

Compare two ULIDs.

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

pub fn main() !void {
    const value1 = try ulid.decodeBase32("01EWJ2BNFTSB4CPJP2C9291V9Q");
    const value2 = try ulid.decodeBase32("01EWJ2CXQHDBB7K18P6GZGPQ9C");
    switch (value1.cmp(value2)) {
        .lt => std.log.info("{s} < {s}", .{&value1.encodeBase32(), &value2.encodeBase32()}),
        .eq => std.log.info("{s} = {s}", .{&value1.encodeBase32(), &value2.encodeBase32()}),
        .gt => std.log.info("{s} > {s}", .{&value1.encodeBase32(), &value2.encodeBase32()}),
    }
}

fn eq(ulid, ulid) bool

Check if two ULIDs are equal.

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

pub fn main() void {
    const value1 = ulid.decode("01EWJ2BNFTSB4CPJP2C9291V9Q");
    const value2 = ulid.decode("01EWJ2CXQHDBB7K18P6GZGPQ9C");
    if (value1.eq(value2)) {
        std.log.info("{s} = {s}", .{&value1.encodeBase32(), &value2.encodeBase32()}),
    } else {
        std.log.info("{s} =/= {s}", .{&value1.encodeBase32(), &value2.encodeBase32()}),
    }
}

MonotonicFactory struct

Creates a ULID factory that ensures that each ulid generated is greater than the last.

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

test "Monotonic ULID factory: sequential output always increases" {
    var ulid_factory = try ulid.MonotonicFactory.init();
    
    var value1 = ulid_factory.now();
    var value2 = ulid_factory.now();
    
    std.testing.expect(ulid.cmp(value2, value1) == .gt);
}