gistfile1.js

$R = function(a,b){
    var r=[]
    for(var i=a;i<=b;i++) r.push(i)
    return r
}

$L = function(){
    var alphabet = "abcdefghijklmnopqrstuvwxyz"
    var typeHint = (typeof arguments[0][0])
    var f = arguments[arguments.length - 1]
    var out = []
    rs = []
    for(var i=0;i<arguments.length-1;i++){
        rs.push(arguments[i])
    }
    // argument now only contains a list of ranges
    var s = ""
    for(var i=0;i<rs.length;i++){
        var id = alphabet[i]
        s += "for(var "+id+"=0;"+id+"<rs["+i+"].length;"+id+"++){"
    }
    s += "out.push(f("
    var l = []
    for(var i=0;i<rs.length;i++){
        l.push(alphabet[i])
    }
    s += l.join(",")
    s += "));"
    for(var i=0;i<rs.length;i++){
        s += "}"
    }
    eval(s)
    return out
}

$L($R(1,10),function(x){
    return (x%2==0)?(x*x):null
})

// returns:
// [0, null, 4, null, 16, null, 36, null, 64, null]

$L($R(0,3), $R(0,3), function(x,y){ return x * y })

// returns:
// [0, 0, 0, 0, 0, 1, 2, 3, 0, 2, 4, 6, 0, 3, 6, 9]