Monoid

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Simple monoid factory in JavaScript. Compatible with the Fantasy Land JS Spec.

Easily define list reductions by providing an identity value and a binary function. Get a free way to reduce a list of monoids with concatAll.

$3

Make a monoid and concat two monoid values.

``js
var M = require('monoid');

var Any = M.Monoid({
identity : false,
binary : function (v1, v2) {
return v1 || v2;
}
});


// Use the monoid instance method
Any(true).append(Any(false)); // => Any(true)

// Or the free function provided by the Monoid module
M.append(Any(true), Any(false)); // => Any(true)

// Reduce an entire list of monoids
M.concatAll([Any(false), Any(false), Any(true)]); // => Any(true)
M.concatAll([Any(false), Any(false), Any(false)]); // => Any(false)
`

Create a function to reduce a list of values using applyWith.

`js
var any = M.applyWith(Any);

any([false, false, true]); // => true
any([false, false, false]); // => true


var Product = M.Monoid({
identity : 1,
binary : function (v1, v2) {
return v1 * v2;
}
});

M.applyWith(Product, [3, 5, 10]); // => 150
`

Note: M.applyWith(, list) is equivelent to M.extract(M.concatAll(list.map())).

Use shorthand syntax for defining binaries. Currently available for +, *, || and &&.

`js
var Sum = M.Monoid({
identity : 0,
binary : '+'
});

var sum = M.applyWith(Sum);

sum([10, 32, 11]) // => 53
`

$3

* More examples/docs
* Add more built in binaries
* Consider additional shorthand var Any = M.Monoid(false, '||')`.

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[travis-url]: https://travis-ci.org/TGOlson/monoid

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