README

string-mismatch

Algorithms for compare strings. Currently the list of available algorithms are:

	Greedy	Levenshtein	Dice Coefficient
Complexity	O(n*k) (k precision)	O(n^2)	O(nlog n)
Good	Fast algorithm	Always the optimal solution	Is based in probabilities and is a really fast algorithm
Bad	The solution is not the optimal	Complexity is O(n^2)	Impossible to see the differences between the strings
		Use n^2 memory
Methods	difference	difference	distance
	distance	distance
Operations for transform the string	insertion	insertion	not apply
	deletion	deletion
		substitution
Class name	`Greedy`	`Levenshtein`	`DiceCoefficient`

Why use string-mismatch:

Ease to install and start using it
Modular library (use only what you want to use).
Support for browser and node applications.
Compatible with es5
Not external dependencies.
Completely documented.
Coverage over 95%.

Install

npm install --save string-mismatch

Getting started

### Nodejs application example

How to use the library and see the differences between two strings:

const sm = require("string-mismatch");
const greedyInstance = new sm.Greedy();

var start = 'This is a test for see how work the library',
    end   = 'This is a test for know how work the new library';

console.log(greedyInstance.differences(start, end));

The result is an object array with the mismatch result. Each object with the next structure:

{
  type: string, // type of sub-string:
                //   'sub' -> substitution
                //   'ins' -> insertion
                //   'del' -> deletion
                //   'eql' -> equal
  value: string // value of the current sub-string
}

The resulting string can be concatenated like the next example:

const sm = require("string-mismatch");
const greedyInstance = new sm.Greedy();

var start = 'This is a test for see how work the library',
    end   = 'This is a test for know how work the new library';

function showResult(diffs) {
    return diffs.reduce(function (text, value) {
        switch (value.type) {
            case 'del':
                return text + '(-' + value.value + ')';
            case 'ins':
                return text + '(+' + value.value + ')';
            case 'sub':
                return text + '(-+' + value.value + ')';
            case 'eql':
                return text + value.value;
        }
    }, '');
}

console.log(showResult(greedyInstance.differences(start, end)));
/*
result:
This is a test for (-see)(+know) how work the (+new )library
*/

This code can be tested in the project's examples. To run the examples use the next command:

npm start

Web application example

Import the library

<!--Greedy algorithm-->
<script src="lib/greedy.min.js" type="application/javascript"></script>
<!--Levenshtein algorithm-->
<script src="lib/levenshtein.min.js" type="application/javascript"></script>

Example with greedy algorithm:

<script type="application/javascript">
    var start = 'This is a test for see how work the library';
    var end = 'This is a test for know how work the new library';
    var alg = new Greedy(options);
    var diffs = alg.differences(start, end);
    console.log(diffs);
</script>

Example with the levenshtein algorithm:

<script type="application/javascript">
    var start = 'This is a test for see how work the library';
    var end = 'This is a test for know how work the new library';
    var alg = new Levenshtein(options);
    var diffs = alg.differences(start, end);
    console.log(diffs);
</script>

Testing code

npm test

Built With

webpack - For build the project
npm - Dependency Management
jest - Jest framework for test

Contributing

All contributions are welcome.

Versioning

We use SemVer for versioning. For the versions available, see the tags on this repository.

Authors

Guillermo González - Initial work - wil92

License

This project is licensed under the MIT License - see the LICENSE.md file for details

Usage no npm install needed!