Novelty Polygonal Mathematics

    liqe
    TypeScript icon, indicating that this package has built-in type declarations

    3.4.0 • Public • Published

    liqe

    Travis build status Coveralls NPM version Canonical Code Style Twitter Follow

    Lightweight and performant Lucene-like parser, serializer and search engine.

    Motivation

    Originally built Liqe to enable Roarr log filtering via cli. I have since been polishing this project as a hobby/intellectual exercise. I've seen it being adopted by various CLI and web applications that require advanced search. To my knowledge, it is currently the most complete Lucene-like syntax parser and serializer in JavaScript, as well as a compatible in-memory search engine.

    Liqe use cases include:

    • parsing search queries
    • serializing parsed queries
    • searching JSON documents using the Liqe query language (LQL)

    Note that the Liqe AST is treated as a public API, i.e., one could implement their own search mechanism that uses Liqe query language (LQL).

    Usage

    import {
      filter,
      highlight,
      parse,
      test,
    } from 'liqe';
    
    const persons = [
      {
        height: 180,
        name: 'John Morton',
      },
      {
        height: 175,
        name: 'David Barker',
      },
      {
        height: 170,
        name: 'Thomas Castro',
      },
    ];

    Filter a collection:

    filter(parse('height:>170'), persons);
    // [
    //   {
    //     height: 180,
    //     name: 'John Morton',
    //   },
    //   {
    //     height: 175,
    //     name: 'David Barker',
    //   },
    // ]

    Test a single object:

    test(parse('name:John'), persons[0]);
    // true
    test(parse('name:David'), persons[0]);
    // false

    Highlight matching fields and substrings:

    test(highlight('name:john'), persons[0]);
    // [
    //   {
    //     path: 'name',
    //     query: /(John)/,
    //   }
    // ]
    test(highlight('height:180'), persons[0]);
    // [
    //   {
    //     path: 'height',
    //   }
    // ]

    Query Syntax

    Liqe uses Liqe Query Language (LQL), which is heavily inspired by Lucene but extends it in various ways that allow a more powerful search experience.

    Liqe syntax cheat sheet

    # search for "foo" term anywhere in the document (case insensitive)
    foo
    
    # search for "foo" term anywhere in the document (case sensitive)
    'foo'
    "foo"
    
    # search for "foo" term in `name` field
    name:foo
    
    # search for "foo" term in `full name` field
    'full name':foo
    "full name":foo
    
    # search for "foo" term in `first` field, member of `name`, i.e.
    # matches {name: {first: 'foo'}}
    name.first:foo
    
    # search using regex
    name:/foo/
    name:/foo/o
    
    # search using wildcard
    name:foo*bar
    
    # boolean search
    member:true
    member:false
    
    # null search
    member:null
    
    # search for age =, >, >=, <, <=
    height:=100
    height:>100
    height:>=100
    height:<100
    height:<=100
    
    # search for height in range (inclusive, exclusive)
    height:[100 TO 200]
    height:{100 TO 200}
    
    # boolean operators
    name:foo AND height:=100
    name:foo OR name:bar
    
    # unary operators
    NOT foo
    -foo
    NOT foo:bar
    -foo:bar
    name:foo AND NOT (bio:bar OR bio:baz)
    
    # implicit AND boolean operator
    name:foo height:=100
    
    # grouping
    name:foo AND (bio:bar OR bio:baz)

    Keyword matching

    Search for word "foo" in any field (case insensitive).

    foo

    Search for word "foo" in the name field.

    name:foo

    Search for name field values matching /foo/i regex.

    name:/foo/i

    Search for name field values matching f*o wildcard pattern.

    name:f*o

    Search for phrase "foo bar" in the name field (case sensitive).

    name:"foo bar"

    Number matching

    Search for value equal to 100 in the height field.

    height:=100

    Search for value greater than 100 in the height field.

    height:>100

    Search for value greater than or equal to 100 in the height field.

    height:>=100

    Range matching

    Search for value greater or equal to 100 and lower or equal to 200 in the height field.

    height:[100 TO 200]

    Search for value greater than 100 and lower than 200 in the height field.

    height:{100 TO 200}

    Wildcard matching

    Search for any word that starts with "foo" in the name field.

    name:foo*

    Search for any word that starts with "foo" and ends with bar in the name field.

    name:foo*bar

    Boolean operators

    Search for phrase "foo bar" in the name field AND the phrase "quick fox" in the bio field.

    name:"foo bar" AND bio:"quick fox"

    Search for either the phrase "foo bar" in the name field AND the phrase "quick fox" in the bio field, or the word "fox" in the name field.

    (name:"foo bar" AND bio:"quick fox") OR name:fox

    Serializer

    Serializer allows to convert Liqe tokens back to the original search query.

    import {
      parse,
      serialize,
    } from 'liqe';
    
    const tokens = parse('foo:bar');
    
    // {
    //   expression: {
    //     location: {
    //       start: 4,
    //     },
    //     quoted: false,
    //     type: 'LiteralExpression',
    //     value: 'bar',
    //   },
    //   field: {
    //     location: {
    //       start: 0,
    //     },
    //     name: 'foo',
    //     path: ['foo'],
    //     quoted: false,
    //     type: 'Field',
    //   },
    //   location: {
    //     start: 0,
    //   },
    //   operator: {
    //     location: {
    //       start: 3,
    //     },
    //     operator: ':',
    //     type: 'ComparisonOperator',
    //   },
    //   type: 'Tag',
    // }
    
    serialize(tokens);
    // 'foo:bar'

    AST

    import {
      type BooleanOperatorToken,
      type ComparisonOperatorToken,
      type EmptyExpression,
      type FieldToken,
      type ImplicitBooleanOperatorToken,
      type ImplicitFieldToken,
      type LiteralExpressionToken,
      type LogicalExpressionToken,
      type RangeExpressionToken,
      type RegexExpressionToken,
      type TagToken,
      type UnaryOperatorToken,
    } from 'liqe';

    There are 11 AST tokens that describe a parsed Liqe query.

    If you are building a serializer, then you must implement all of them for the complete coverage of all possible query inputs. Refer to the built-in serializer for an example.

    Compatibility with Lucene

    The following Lucene abilities are not supported:

    Recipes

    Handling syntax errors

    In case of a syntax error, Liqe throws SyntaxError.

    import {
      parse,
      SyntaxError,
    } from 'liqe';
    
    try {
      parse('foo bar');
    } catch (error) {
      if (error instanceof SyntaxError) {
        console.error({
          // Syntax error at line 1 column 5
          message: error.message,
          // 4
          offset: error.offset,
          // 1
          offset: error.line,
          // 5
          offset: error.column,
        });
      } else {
        throw error;
      }
    }

    Highlighting matches

    Consider using highlight-words package to highlight Liqe matches.

    Development

    Compiling Parser

    If you are going to modify parser, then use npm run watch to run compiler in watch mode.

    Benchmarking Changes

    Before making any changes, capture the current benchmark on your machine using npm run benchmark. Run benchmark again after making any changes. Before committing changes, ensure that performance is not negatively impacted.

    Tutorials

    Keywords

    Install

    npm i liqe@3.4.0

    Version

    3.4.0

    License

    BSD-3-Clause

    Unpacked Size

    143 kB

    Total Files

    66

    Last publish

    Collaborators

    • gajus