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.

``javascript
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:

`javascript
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:

`javascript
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

$3

Install using npm

npm install breakable

`javascript
var breakable = require("breakable");
`

$3

Clone the repo and include it in a script tag

git clone https://github.com/olov/breakable.git

`html

``