https://github.com/anywhichway/js-generics

A generic function definition and dispatch library for Javascript.
https://github.com/anywhichway/js-generics

Last synced: about 4 hours ago
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A generic function definition and dispatch library for Javascript.

• Host: GitHub
• URL: https://github.com/anywhichway/js-generics
• Owner: anywhichway
• License: mit
• Created: 2015-11-30T11:50:20.000Z (almost 9 years ago)
• Default Branch: master
• Last Pushed: 2016-01-27T16:07:26.000Z (almost 9 years ago)
• Last Synced: 2024-09-18T11:46:01.642Z (about 2 months ago)
• Language: JavaScript
• Size: 10.7 KB
• Stars: 5
• Watchers: 3
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# js-generics

A generic function definition and multi-dispatch library for JavaScript.

Multi-dispatch generic functions support the selection and execution of a function based on the types and number of arguments.

[![Build Status](https://travis-ci.org/anywhichway/js-generics.svg)](https://travis-ci.org/anywhichway/js-generics)

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# Installation

npm install js-generics

The index.js and package.json files are compatible with [node-require](http://www.github.com/anywhichway/joqular) so that js-generics can be served directly to the browser from the node-modules/js-generics directory when using node Express.

# Usage

Multi-dispatch generic functions support the selection and execution of a function based on the types and number of arguments. A common use is supporting mathematical operations on different types of objects. For example:

```

var sum = generic(function() { throw new Error("can't sum " + JSON.stringify(arguments)); } )

	.method("number","number",

			 function(arg1,arg2) { return arg1 + arg2; })

	.method(function(arg) { return arg instanceof Array;},"number",

			 function(arg1, arg2) { arg1.forEach(function(item,i) { arg1[i] += arg2; }); return arg1; });

```

In the example above the generic function *sum* is defined to throw an error if no matching dispatch can be found. Matching dispatches have two arguments of type number or a first argument of kind array and a second of type number.

The general form of usage is:

```

generic().method([,...],)[.method([,...],),...]

```

*\* - This function is called if no matching dispatches are found. It can take any form and is called as *.apply(this,arguments)*. As a result generic functions can be included as methods on objects.

*\* - These should be primitive type names or functions. If a function, it's sole responsibility is to return *true* or *false* if the argument type is correct. The number of \ must match the number of arguments to \, or the last \ must be the special value *generic.VARGS*.

*\* - This function does the desired work. It is called as *\.apply(this,arguments)*.

.*method* calls can be chained and the last matching method is the one invoked by the dispatcher.

# Release History (reverse chronological order)

v0.0.6 2016-01-03 Corrected markdown issues is README.

v0.0.5 2016-01-03 Added unit tests and documentation.

v0.0.4 2015-12-13 Codacy improvements

v0.0.3 2015-12-13 Initial public commit.

# License

MIT License - see LICENSE file