feat: allow plain function usage of fn.compose

Author: medikoo

README.md

@@ -490,6 +490,10 @@ Applies the functions in reverse argument-list order.
 
 _f1.compose(f2, f3, f4)(…args) =def f1(f2(f3(f4(…arg))))_
 
+`compose` can also be used in plain function form as:
+
+_compose(f1, f2, f3, f4)(…args) =def f1(f2(f3(f4(…arg))))_
+
 #### fn.copy() _(es5-ext/function/#/copy)_
 
 Produces copy of given function

function/#/compose.js

@@ -1,6 +1,7 @@
 "use strict";
 
-var callable = require("../../object/valid-callable")
+var isValue  = require("../../object/is-value")
+  , callable = require("../../object/valid-callable")
   , aFrom    = require("../../array/from");
 
 var apply = Function.prototype.apply
@@ -9,7 +10,8 @@ var apply = Function.prototype.apply
 
 module.exports = function (fnIgnored/*, …fnn*/) {
 	var fns, first;
-	fns = [this].concat(aFrom(arguments));
+	var args = aFrom(arguments);
+	fns = isValue(this) ? [this].concat(args) : args;
 	fns.forEach(callable);
 	fns = fns.reverse();
 	first = fns[0];

test/function/#/compose.js

@@ -4,4 +4,7 @@ var f = function (a, b) { return ["a", arguments.length, a, b]; }
   , g = function (a) { return ["b", arguments.length].concat(a); }
   , h = function (a) { return ["c", arguments.length].concat(a); };
 
-module.exports = function (t, a) { a.deep(t.call(h, g, f)(1, 2), ["c", 1, "b", 1, "a", 2, 1, 2]); };
+module.exports = function (t, a) {
+	a.deep(t.call(h, g, f)(1, 2), ["c", 1, "b", 1, "a", 2, 1, 2]);
+	a.deep(t(h, g, f)(1, 2), ["c", 1, "b", 1, "a", 2, 1, 2]);
+};