🐶 purs-puppy

An LR parser generator for PureScript.

Puppy turns a grammar into a PureScript parser. You write the grammar and what each rule means; Puppy works out the parsing table and writes a module.

npm install --save-dev purs-puppy

Puppy assumes your project is organised with spago. Grammars use the .pursy extension and live under src:

puppy -p my-package

That finds every grammar under the package's src and writes each one's parser module beside it. A single grammar can be named directly:

puppy src/Foo/Parser.pursy -m Foo.Parser

A generated module depends on puppy-runtime and nothing else of Puppy's. The generator is not needed to build or run what it produced.

puppy-runtime is not in the PureScript registry yet, so for now name it as an extra package pointing at the subdirectory it lives in:

workspace:
  extraPackages:
    puppy-runtime:
      git: https://github.com/katsujukou/puppy.git
      ref: v0.1.0
      subdir: puppy-runtime

Read the documentation for the grammar language, the shape of what Puppy generates, and how to read a conflict report.