NeoYAML

A Pharo Smalltalk adapter library that converts between YAML text and the same object shapes (Dictionary, Array/OrderedCollection, Association, scalars) that NeoJSON's NeoJSONWriter/NeoJSONReader use — in both directions, via NeoYAMLWriter and NeoYAMLReader.

Both the YAML writer and reader are implemented from scratch, with no external YAML library dependency — NeoYAML depends only on NeoJSON itself.

Requirements

Smalltalk	Version
Pharo	12.0, 13.0

The only dependency is NeoJSON, which the baseline loads for you.

Installation

Metacello new
  baseline: 'NeoYAML';
  repository: 'github://newapplesho/NeoYAML:main/src';
  load.

To work from a local checkout instead, point the repository at it: 'tonel://', '<repository root>/src'.

Usage

NeoYAMLWriter writeJSON: '{"name":"Pharo","tags":["smalltalk","yaml"]}'.

produces:

name: Pharo
tags:
  - smalltalk
  - yaml

NeoYAMLWriter write: anObject converts an already-parsed NeoJSON-shaped object (Dictionary, Array/OrderedCollection, Association, or a scalar) directly, without going through JSON text.

The other direction:

NeoYAMLReader fromString: 'name: Pharo' , String lf , 'tags:' , String lf , '  - smalltalk'.

produces a Dictionary equivalent to what NeoJSONReader would build from the corresponding JSON — NeoYAMLReader covers exactly the block-style subset NeoYAMLWriter emits (see ROADMAP.md for what's out of scope).

The same conversions are reachable from NeoJSON's own classes, so you do not have to name NeoYAMLWriter/NeoYAMLReader:

NeoJSONWriter toYAML: aDictionary.
NeoJSONReader fromYAML: 'key: value'.
NeoJSONObject fromYAML: 'name: Pharo'.   "message-style access: obj name"

For more examples — multi-line strings, multi-document streams, round-tripping, and a method summary — see docs/usage.md.

Documentation

• Usage — multi-line strings, multi-document streams, round-tripping, and a method summary
• Architecture — the scan / parse / construct pipeline and the read/write flows (日本語)
• Parser — how syntactic analysis is implemented (日本語)
• Development — building and testing the library in Pharo
• Roadmap — done, planned, and out of scope

Packages

Package	Role
NeoYAML-Core	NeoYAMLWriter (object → YAML text); NeoYAMLReader, a thin facade over the two packages below; NeoYAMLConstructor, turning a node tree into the final Dictionary/Array/scalar shapes
NeoYAML-Core-Scan	NeoYAMLScanner — turns YAML source text into blank-line-preserving physical line records
NeoYAML-Core-Parse	NeoYAMLParser/NeoYAMLNode — the parse stage, building an untyped node tree
BaselineOfNeoYAML	Metacello baseline
NeoYAML-Tests	SUnit tests

fixtures/ holds standalone .yaml files read from disk by NeoYAMLFixtureTest, covering the disk-read path alongside the inline string literals NeoYAMLReaderTest/NeoYAMLWriterTest use. It lives outside src/ since Tonel does not define any handling for non-.st files inside a package directory.

Development

This is a Pharo / Tonel project. With a local Pharo image (make setup):

make load    # load/reload the project into the image
make test    # run the test suite (pattern NeoYAML.*)
make ui      # open the Pharo GUI

See docs/development.md for the full workflow.