Package Exports

breakable

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (breakable) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

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>