ppanyukov / funcs

Functional extensions and support for C#

FunCs

Functional extensions and support for C#.

What it's for

Very lightweight syntax functional support for C#, for things which either don't exist, or a pain to use.

Currently included:

• Use var to declare lambdas;
• Functional composition;
• Partial function application (currying).

Use 'var' to declare lambdas:

What is a less of a pain and makes more sense to you? And what is easier to convert to a method should you want to?

// Standard C#
Func<int, string> f = (x) => x.ToString();

// With FunCs
var f = Fun.function((int x) => x.ToString());

Restrictions:

• Can only use inside a method: can't use var to declare instance members :(
• Up to 9 input parameters;
• It's a Func, so must have a return value, can't do `void.

Function composition: create functions by chaining them together.

var stringToInt = Fun.function((string s) => int.Parse(s));
var intToHexString = Fun.function((int n) => n.ToString("X"));

// compose
var stringToHexString = Fun.compose(stringToInt, intToHexString);

// or, using extension
var stringToHexString = stringToInt.compose(intToHextString);

// use it
var s = stringToHexString("255");  // = "FF"

Restrictions:

• Can only use with Func<> types.
• Cannot use with methods :( For a somewhat unconvincing answer why, see Eric Lippert's post on SO.

Partial function application (currying)

var plus = Fun.function((int x1, int x2) => x1 + x2);
var plus10 = plus.curry(10);    // or Fun.curry(plus, 10)
var r1 = plus(2);               // = 10 + 2 = 12
var r2 = plus(5);               // = 10 + 5 = 15

Restrictions:

• Same as with compose.

Getting the stuff

This is a sort of a "beta" at the moment. More stuff will be added.

.NET Version Support

Currently only 4.0 and 4.5.

If there is a demand for earlier versions (3.5, 3.0 and 2.0), add an issue to this project.

Nuget

There is a nuget package for it here.

Binaries

There are pre-built binaries in published directory. Feel free to grab those.

Source code

Feel free to use as a source code. It should be trivial to do so.

License

MIT license. Feel free to use either as binary releases or as source code.

funcs's Issues

compose should work with Func<TResult>

Currently compose works with Func<T,TResult> but doesn't work with Func<TResult>, i.e. those functions which don't take any arguments.