Haskell JS ideas

functions.js

var haskellFunction = hs.create(
    hs.when('[]', function() {

    }),
    hs.when('(x:xs)', 
        //
        hs.gaurd(hs.gte(5), function(self, a, x, xs, b) {

        }),
        hs.gaurd(hs.lte(2), function(self, a, x, xs, b) {

        }),
        function(self, a, x, xs, b) {

        },
    ).where(function(x, xs) {
        var a = 20,
            b = 100;

        return [a, x, xs, b];
    });
);

// Alternate idea with types
var Phone = Type({name: String, number: String});
var Person = Type({first: String, last: String, phones: [Phone]});

var myPerson = Person('Sally', 'Dengus', [Phone('Home', '4444'), Phone('Mobile', '1234')]);

var doSomething = Func.create(
    Func.signature([Person], Number).returns(String),
    Func.when('_ 0', function() {
        return '';
    }),
    Func.when('[] _', function(self) {
        return self([], 0);
    }),
    Func.when('x:xs n', function(self, a, x, xs, n) {
        return first(x.phones).number + self(xs, n - 1);
    })
    .using(function(x, xs, n) {
        var a = 20;

        return [a, x, xs, n];
    });
);