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    fm-index.jsx

    0.3.0 • Public • Published

    fm-index.jsx

    Build Status

    Synopsis

    FM-index is the fastest full text search algorithm using a compressed index file. This is FM-index for JSX/JS/AMD/Common.js.

    Motivation

    FM-index is the alternate search algorithm of an inverse index algorithm. FM-index has the following advantages:

    1. It doesn't need to split word (like N-gram). It is good for CJK languages.
    2. It can recreate original document from the index file
    3. Index file is compressed.
    4. Easy to control the performance and the index file size.

    Code Example

    Use from JSX

    import "fm-index.jsx";
     
    class _Main {
        static function main(argv : string[]) : void
        {
            var fm = new FMIndex();
            fm.push("hello");
            fm.push("world");
            this.fm.build(5);
            console.log(this.fm.search('world')); // -> [5]
        }
    }

    Use from node.js

    var FMIndex = require('fm-index.common.js').FMIndex;

    Use from require.js

    // use fm-index.amd.js
    define(['fm-index.amd.jsx'], function (fmindex) {
     
        var fmindex = fmindex.FMIndex();
        // Write simple usage here!
    });

    Use via standard JSX function

    <script src="fm-index.js" type="text/javascript"></script>
    <script type="text/javascript">
    window.onload = function () {
        var FMIndex = JSX.require("lib/fm-index.js").FMIndex;
    });
    </script> 

    Use via global variables

    <script src="fm-index.global.js" type="text/javascript"></script>
    <script type="text/javascript">
    window.onload = function () {
        var fmindex = new FMIndex();
    });
    </script> 

    Installation

    $ npm install fm-index.jsx

    You should add the following modules to package.json if you want to use from JSX:

    • burrows-wheeler-transform.jsx (0.3.x)
    • wavelet-matrix.jsx (0.3.x)
    • binary-io.jsx (0.3.x)
    • bit-vector.jsx (0.4.x)
    • binary-support.jsx (0.2.x)

    If you want to use this library from other JSX project, install like the following:

    $ npm install fm-index.jsx --save-dev

    or add like these lines to your parent project's package.json:

       devDependencies: {
           "fm-index.jsx": "~0.3.0"
       },
       peerDepenencies: {
           "fm-index.jsx": "~0.3.0"
       }

    And add node_modules/fm-index.jsx/src as a search path. You should add to peerDepenencies if your product is library.

    API Reference

    class FMIndex()

    Constructor.

    FMIndex.push(str : string) : void

    Append string.

    FMIndex.contentSize()

    Return total length of pushed string. It is available before build().

    FMIndex.build(ddic : int, maxChar : int = 65535) : void

    Build search index. ddic is a cache density. (1 / ddic) * 100 % is a actual cache rate. If ddic == 1, densty = 100%, it provides maximum speed but it use match memory and storage. Initial recommendation value is 50.

    maxChar is a maximum character code. If you reduce this, you can save memory.

    FMIndex.size()

    Return contetn size. It is available after build().

    FMIndex.search(keyword : string) : int[]

    Return position list that includes keyword.

    FMIndex.getSubstring(pos : int, len : int) : string

    Return original document content.

    FMIndex.dump(output : BinaryOutput) : void

    Export bit-vector.

    FMIndex.load(input : BinaryInput) : void

    Import bit-vector.

    Development

    JSX

    Don't be afraid JSX! If you have an experience of JavaScript, you can learn JSX quickly.

    • Static type system and unified class syntax.
    • All variables and methods belong to class.
    • JSX includes optimizer. You don't have to write tricky unreadalbe code for speed.
    • You can use almost all JavaScript API as you know. Some functions become static class functions. See reference.

    Setup

    To create development environment, call following command:

    $ npm install

    Repository

    Run Test

    $ grunt test

    Build

    $ grunt build

    Generate API reference

    $ grunt doc

    Author

    License

    MIT

    Complete license is written in LICENSE.md.

    Keywords

    none

    Install

    npm i fm-index.jsx

    DownloadsWeekly Downloads

    13

    Version

    0.3.0

    License

    MIT

    Last publish

    Collaborators

    • shibu