Data formats — JSON & YAML

JSON::Fast, JSON::Tiny and YAMLish under Raku++ — parsing, generating, round-tripping.

The everyday serialization modules work unmodified. Every example below runs under Raku++ with the pinned module sources; the output shown is verified against both the interpreter and Rakudo at build time.

JSON::Fast #

The de-facto standard JSON module. from-json gives you plain hashes and arrays; to-json goes the other way (:sorted-keys makes output deterministic, :!pretty keeps it on one line).

use JSON::Fast;

my $config = from-json(q:to/END/);
    { "server": { "port": 8080, "tls": false },
      "backends": ["alpha", "beta"] }
    END

say $config<server><port>;
say $config<backends>.join(', ');
say to-json({ ok => True, n => 42 }, :sorted-keys, :!pretty);

8080
alpha, beta
{"n":42,"ok":true}

JSON::Tiny #

The lighter alternative — a grammar-driven parser in a few hundred lines. Both directions work: from-json parses with a real Raku grammar, and to-json \u-escapes anything outside printable ASCII, exactly like Rakudo.

use JSON::Tiny;

my $parsed = from-json('{"name": "raku", "level": [1, 2.5, true]}');
say $parsed<name>;
say $parsed<level>[1];
say to-json(["four", "héllo"]);

raku
2.5
[ "four", "h\u00e9llo" ]

YAMLish #

YAML in pure Raku. load-yaml parses one document; save-yaml emits one.

use YAMLish;

my $doc = load-yaml(q:to/END/);
    name: rakupp
    langs:
      - Raku
      - C++
    END

say $doc<name>;
say $doc<langs>.elems;

rakupp
2