waffpi / zig-yaml

YAML parser for Zig

zig-yaml

YAML parser for Zig

What is it?

This lib is meant to serve as a basic (or maybe not?) YAML parser for Zig. It will strive to be YAML 1.2 compatible but one step at a time.

This is very much a work-in-progress, so expect things to break on a regular basis. Oh, I'd love to get the community involved in helping out with this btw! Feel free to fork and submit patches, enhancements, and of course issues.

Basic usage

The parser currently understands a few YAML primitives such as:

• explicit documents (---, ...)
• mappings (:)
• sequences (-, [, ])

In fact, if you head over to examples/ dir, you will find YAML examples that have been tested against this parser. You can also have a look at end-to-end test inputs in test/ directory.

If you want to use the parser as a library, add it as a package the usual way, and then:

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

const source =
    \\names: [ John Doe, MacIntosh, Jane Austin ]
    \\numbers:
    \\  - 10
    \\  - -8
    \\  - 6
    \\nested:
    \\  some: one
    \\  wick: john doe
    \\finally: [ 8.17,
    \\           19.78      , 17 ,
    \\           21 ]
;

1. For untyped, raw representation of YAML, use Yaml.load:

var untyped = try yaml.Yaml.load(std.testing.allocator, source);
defer untyped.deinit();

try std.testing.expectEqual(untyped.docs.items.len, 1);

const map = untyped.docs.items[0].map;
try std.testing.expect(map.contains("names"));
try std.testing.expectEqual(map.get("names").?.list.len, 3);

2. For typed representation of YAML, use Yaml.parse:

const Simple = struct {
    names: []const []const u8,
    numbers: []const i16,
    nested: struct {
        some: []const u8,
        wick: []const u8,
    },
    finally: [4]f16,
};

const simple = try untyped.parse(Simple);
try std.testing.expectEqual(simple.names.len, 3);

3. To convert Yaml structure back into text representation, use Yaml.stringify:

try untyped.stringify(std.io.getStdOut().writer());

which should write the following output to standard output when run:

names: [ John Doe, MacIntosh, Jane Austin  ]
numbers: [ 10, -8, 6  ]
nested:
    some: one
    wick: john doe
finally: [ 8.17, 19.78, 17, 21  ]