Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Break out of functions, recursive or not, in a more composable way than by using exceptions explicitly. Non-local return.
JavaScript
Branch: master

Fetching latest commit…

Cannot retrieve the latest commit at this time

Failed to load latest commit information.
examples
test
LICENSE
README.md
breakable.js
package.json

README.md

breakable.js

Break out of functions, recursive or not, in a more composable way than by using exceptions explicitly. Non-local return.

Usage

You can use breakable to break out of simple loops like this example but note that it is often simpler to just use .some instead. Anyways, here's a minimal example.

var breakable = require("breakable");

breakable(function(brk) {
    arr.forEach(function(v) {
        if (...) {
           brk();
        }
    });
});

Pass a value to brk and it becomes the return-value of breakable.

breakable is useful when you want to break out of a deep recursion, passing a value, without riddling your code with exception ceremony.

Instead of:

var esprima = require("esprima").parse;
var traverse = require("ast-traverse");
var ast = esprima("f(!x, y)");

var val;
try {
    traverse(ast, {pre: function(node) {
        if (node.type === "UnaryExpression" && node.operator === "!") {
            val = node.argument;
            throw 0;
        }
    }});
} catch(e) {
    if (val === undefined) {
        throw e; // re-throw if it wasn't our exception
    }
}

console.dir(val); // { type: 'Identifier', name: 'x' }

you use breakable and do:

var breakable = require("breakable");
var esprima = require("esprima").parse;
var traverse = require("ast-traverse");
var ast = esprima("f(!x, y)");

var val = breakable(function(brk) {
    traverse(ast, {pre: function(node) {
        if (node.type === "UnaryExpression" && node.operator === "!") {
            brk(node.argument);
        }
    }});
});

console.dir(val); // { type: 'Identifier', name: 'x' }

Installation

Node

Install using npm

npm install breakable
var breakable = require("breakable");

Browser

Clone the repo and include it in a script tag

git clone https://github.com/olov/breakable.git
<script src="breakable/breakable.js"></script>
Something went wrong with that request. Please try again.