Hm-lang-light NPM

JavaScript fast, lightweight parsers for Hindley-Milner type expressions using Parsimmon for parsers formulation.

Features

Is able to parse all Sanctuary and Fantasy Land type declarations
Only one self-contained dependency
Clear and extensible
Fast combinator parsing
About 1.8k LoC total
More comprehensive tests

Examples

import HMLang from "hm-lang-light"
import _runP  from "hm-lang-light/run-parser"

const runP    = _runP (HMLang)

runP ("declaration")
     ("ap :: Applicative m => m (a -> b) -> m a -> m b")

HMLang.declaration
  .tryParse("reverse :: (Applicative f, Foldable f, Monoid (f a)) => f a -> f a")

// Method -with complex type signature-
runP ("declaration")
     ("traverse :: (Applicative f, Traversable t) => t a ~> (TypeRep f, a -> f b) -> f (t b)")

// Record syntax sugar
runP ("declaration")
     ("hello :: a -> { x :: String, y :: a }")

// `FlexibleContexts` enabled by design, also supporting record syntax
HMLang.constraint
  .parse("M (a -> b) {c :: Int}") // {status: true, ...}

See tests for more examples.