jolt-yaml

YAML parsing and serialization for Jolt, bound to the system libyaml through jolt.ffi and exposed as a clean Clojure API plus a SnakeYAML engine v2 surface for yamlscript compatibility.

Use it

(require '[jolt.yaml :as yaml])

;; Parse a YAML string
(yaml/load "foo: 1\nbar: 2\n")
;; => {"foo" 1, "bar" 2}

;; Keywords opt-in
(yaml/load "hello: world\n" {:keywords true})
;; => {:hello "world"}

;; Multi-document streams
(yaml/load-all "---\na: 1\n---\nb: 2\n")
;; => ({"a" 1} {"b" 2})

;; Serialize Clojure data to YAML
(yaml/dump {:a [1 2 3]})
;; => "a:\n- 1\n- 2\n- 3\n"

clj-yaml compat

(require '[clj-yaml.core :as cy])

;; keywords: true by default (matching clj-yaml)
(cy/parse-string "a: 1\n")
;; => {:a 1}

(cy/generate-string {:hello "world"})

SnakeYAML surface

(require '[jolt.yaml.snakeyaml])

(import '(org.snakeyaml.engine.v2.api LoadSettings)
        '(org.snakeyaml.engine.v2.api.lowlevel Parse))

(let [parser (new Parse (.build (LoadSettings/builder)))
      events (.parseString parser "hello\n")]
  ...)

What's provided

• jolt.yaml — the public API: load, load-all, dump / generate-string.
• jolt.yaml.ffi — low-level libyaml bindings: parser lifecycle, event pump, struct field readers at baked offsets (C offsetof probe, ARM64 macOS 0.2.5).
• jolt.yaml.snakeyaml — org.snakeyaml.engine.v2 classes registered as Jolt host objects: LoadSettings / Parse / all 10 event types with marks.
• clj-yaml.core — clj-commons/clj-yaml compatible API (parse-string, parse-stream, generate-string).

Native dependency

libyaml is declared :jolt/native in deps.edn and loaded before the namespace. On macOS via Homebrew at /opt/homebrew/opt/libyaml/lib/libyaml.dylib; on Linux as libyaml-0.so.2.

Build and test

jolt -M:test   # run the test suite

deps.edn

{:deps {io.github.jolt-lang/yaml {:git/sha "..."}}}