npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2026 – Pkg Stats / Ryan Hefner

extra-parser

v0.7.1

Published

A functional parser toolkit

Readme

extra-parser

A functional parser toolkit.

Install

npm install --save extra-parser
# or
yarn add extra-parser

API

interface IToken {
  tokenType: string
  value: string
}

interface INode {
  nodeType: string
}

interface ITokenPatternMatch<Token extends IToken> {
  consumed: number
  token: Token
}

interface INodePatternMatch<Node extends INode> {
  consumed: number
  node: Node
}

interface ITokenPattern<Token extends IToken = IToken> {
  (text: string): ITokenPatternMatch<Token> | Falsy
}

interface INodePattern<Token extends IToken = IToken, Node extends INode = INode> {
  (tokens: ReadonlyArray<Token>): INodePatternMatch<Node> | Falsy
}

type MapSequenceToPatterns<
  Sequence extends ReadonlyArray<Token | Node>
, Token extends IToken = IToken
, Node extends INode = INode
> = {
  [Index in keyof Sequence]:
    [Sequence[Index]] extends [infer TokenOrNode]
  ? (
      TokenOrNode extends Token
      ? string
    : TokenOrNode extends Node
      ? INodePattern<Token, TokenOrNode>
    : never
    )
  : never
}

type MapSequenceToMatches<
  Sequence extends ReadonlyArray<Token | Node>
, Token extends IToken = IToken
, Node extends INode = INode
> = {
  [Index in keyof Sequence]:
    [Sequence[Index]] extends [infer TokenOrNode]
  ? (
      TokenOrNode extends IToken
      ? Token
    : TokenOrNode extends INode
      ? INodePatternMatch<TokenOrNode>
    : never
    )
  : never
}

tokenize

function tokenize<Token extends IToken = IToken>(
  patterns: Array<ITokenPattern<Token>>
, text: string
): IterableIterator<Token>

parse

function parse<Token extends IToken = IToken, Node extends INode = INode>(
  patterns: Array<INodePattern<Token, Node>>
, tokens: Token[]
): IterableIterator<Node>

consumeNode

function consumeNode<
  Token extends IToken = IToken
, Node extends INode = INode
>(
  nodePattern: INodePattern<Token, Node>
, tokens: Token[]
): INodePatternMatch<Node> | Falsy

consumeToken

function consumeToken<Token extends IToken = IToken>(
  tokenType: string
, tokens: Token[]
): Token | Falsy

matchAnyOf

function matchAnyOf<
  Token extends IToken = IToken
, Node extends INode = INode
>(
  nodePatterns: ReadonlyArray<INodePattern<Token, Node>>
, tokens: ReadonlyArray<Token>
): INodePatternMatch<Node> | Falsy

matchSequence

function matchSequence<
  Sequence extends ReadonlyArray<Token | Node>
, Token extends IToken = IToken
, Node extends INode = INode
>(
  patterns: MapSequenceToPatterns<Sequence, Token, Node>
, tokens: ReadonlyArray<Token>
): MapSequenceToMatches<Sequence, Token, Node> | Falsy

matchRepetitions

function matchRepetitions<
  Sequence extends ReadonlyArray<Token | Node>
, Token extends IToken = IToken
, Node extends INode = INode
>(
  patterns: MapSequenceToPatterns<Sequence, Token, Node>
, tokens: ReadonlyArray<Token>
, options?: {
    minimumRepetitions?: number = 1
    maximumRepetitions?: number = Infinity
  }
): Array<Token | INodePatternMatch<Node>> | Falsy

createTokenPatternFromRegExp

function createTokenPatternFromRegExp<Token extends IToken>(
  tokenType: Token['tokenType']
, regExp: RegExp
): ITokenPattern<IToken>

createUnaryOperatorExpressionNodePattern

interface IUnaryOperatorExpressionNode<
  NodeType extends string
, RightNode extends INode
> extends INode {
  nodeType: NodeType
  right: RightNode
}

function createUnaryOperatorExpressionNodePattern<
  Token extends IToken
, Node extends IUnaryOperatorExpressionNode<string, RightNode>
, RightNode extends INode
>(params: {
  nodeType: Node['nodeType']
  leftTokenType: string
  rightNodePattern: INodePattern<Token, RightNode>
}): INodePattern<
  Token
, IUnaryOperatorExpressionNode<Node['nodeType'], Node['right']>
>

createBinaryOperatorExpressionNodePattern

interface IBinaryOperatorExpressionNode<
  NodeType extends string
, LeftNode extends INode
, RightNode extends INode
> extends INode {
  nodeType: NodeType
  left: LeftNode
  right: RightNode
}

function createBinaryOperatorExpressionNodePattern<
  Token extends IToken
, Node extends IBinaryOperatorExpressionNode<string, LeftNode, RightNode>
, LeftNode extends INode
, RightNode extends INode
>(params: {
  nodeType: Node['nodeType']
  centerTokenType: string
  leftNodePattern: INodePattern<Token, LeftNode>
  rightNodePattern: INodePattern<Token, RightNode>
}): INodePattern<
  Token
, IBinaryOperatorExpressionNode<Node['nodeType'], Node['left'], Node['right']>
>

createGroupedExpressionNodePattern

function createGroupedExpressionNodePattern<
  Token extends IToken
, CenterNode extends INode
>(params: {
  leftTokenType: string
  rightTokenType: string
  centerNodePattern: INodePattern<Token, CenterNode>
}): INodePattern<Token, CenterNode>

createValueExpressionNodePattern

interface IValueExpressionNode<
  NodeType extends string
, Value
> extends INode {
  nodeType: NodeType
  value: Value
}

function createValueExpressionNodePattern<
  Token extends IToken
, Node extends IValueExpressionNode<string, Value>
, Value
>(params: {
  nodeType: Node['nodeType']
  valueTokenType: string
  transformValue: (value: string) => Value
}): INodePattern<Token, IValueExpressionNode<Node['nodeType'], Node['value']>>