hm-parser

library0.1.5jsnpmunverified

A parser for Hindley-Milner type signatures, designed as a drop-in replacement for hindley-milner-parser-js but without its babel-polyfill dependency and performance issues. Version 0.1.5 is the latest stable release, with infrequent updates. It supports Haskell-like syntax with JS-specific sugar for methods. Faster and more compatible with modern tooling than the original.

testing

npm install hm-parser

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · HM-PARSER

hm-parser

testingjavascriptv0.1.5

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

parse

✓ import { parse } from 'hm-parser'

✗ import HMP from 'hm-parser'

The package exports a named object with a parse method; default import does not exist.

HMP

✓ import * as HMP from 'hm-parser'

✗ const HMP = require('hm-parser').parse

CommonJS usage: const HMP = require('hm-parser'). Default import is not available; use namespace import.

parse

✓ const { parse } = require('hm-parser')

✗ const parse = require('hm-parser')

CommonJS destructuring is required to get the parse function.

Parses a Hindley-Milner type signature and outputs the AST.

const { parse } = require('hm-parser'); const result = parse('hello :: a -> Maybe a'); console.log(JSON.stringify(result, null, 2)); // { // "name": "hello", // "constraints": [], // "type": { // "type": "function", // "text": "", // "children": [ // { "type": "typevar", "text": "a", "children": [] }, // { "type": "typeConstructor", "text": "Maybe", "children": [ // { "type": "typevar", "text": "a", "children": [] } // ]} // ] // } // }

Debug

Known issues

gotchaThe package does not export a default export; attempting to import it as default will result in undefined.

fix

Use named import or namespace import as shown in imports.

affects: >=0.0.0

gotchaThe parse function expects a string with a type signature; passing malformed input will throw an error.

fix

Ensure input follows Hindley-Milner syntax supported by the parser.

affects: >=0.0.0

gotchaThe package is a drop-in replacement for hindley-milner-parser-js but has a different API: it exports an object with a parse method, not the function directly.

fix

Use const { parse } = require('hm-parser') instead of const parse = require('hindley-milner-parser-js').

affects: >=0.0.0

Errors

Common errors & fixes

TypeError: HMP.parse is not a function

Importing the default export instead of the named export.

fix

Use const { parse } = require('hm-parser') or import { parse } from 'hm-parser'.

Cannot find module 'hm-parser'

Package not installed.

fix

Run npm install hm-parser or yarn add hm-parser.

Unexpected token

Invalid type signature syntax.

fix

Check the input string for correct Hindley-Milner syntax (e.g., 'hello :: a -> Maybe a').

Upgrade

Version history

0.1.5latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

8 hits · last 30 days

node

Resources

githubhttps://github.com/xodio/hm-parser ↗

packagehm-parser ↗

homepagehttps://github.com/xodio/hm-parser#readme ↗