March 2014 update

Task/First-class-functions/D/first-class-functions-1.d

@@ -1,16 +1,9 @@
-import std.stdio, std.math, std.typetuple, std.functional;
-
-enum sin  = (in real x) => std.math.sin(x),
-     asin = (in real x) => std.math.asin(x),
-     cos  = (in real x) => std.math.cos(x),
-     acos = (in real x) => std.math.acos(x),
-     cube = (in real x) => x ^^ 3,
-     cbrt = (in real x) => std.math.cbrt(x);
-
 void main() {
-    alias TypeTuple!(sin,  cos,  cube) dir;
-    alias TypeTuple!(asin, acos, cbrt) inv;
-    foreach (i, f; dir) {
+    import std.stdio, std.math, std.typetuple, std.functional;
+
+    alias dir = TypeTuple!(sin,  cos,  x => x ^^ 3);
+    alias inv = TypeTuple!(asin, acos, cbrt);
+    // foreach (f, g; staticZip!(dir, inv))
+    foreach (immutable i, f; dir)
         writefln("%6.3f", compose!(f, inv[i])(0.5));
-    }
 }

Task/First-class-functions/D/first-class-functions-2.d

@@ -1,18 +1,18 @@
-T delegate(S) compose(T, U, S)(in T function(in U) f,
-                               in U function(in S) g) {
-    return s => f(g(s));
-}
-
 void main() {
     import std.stdio, std.math, std.range;
 
-    immutable sin  = (in real x) => sin(x),
-              asin = (in real x) => asin(x),
-              cos  = (in real x) => cos(x),
-              acos = (in real x) => acos(x),
-              cube = (in real x) => x ^^ 3,
-              cbrt = (in real x) => cbrt(x);
+    static T delegate(S) compose(T, U, S)(in T function(in U) f,
+                                          in U function(in S) g) {
+        return s => f(g(s));
+    }
 
-    foreach (f, g; zip([sin, cos, cube], [asin, acos, cbrt]))
+    immutable sin  = (in real x) pure nothrow => x.sin,
+              asin = (in real x) pure nothrow => x.asin,
+              cos  = (in real x) pure nothrow => x.cos,
+              acos = (in real x) pure nothrow => x.acos,
+              cube = (in real x) pure nothrow => x ^^ 3,
+              cbrt = (in real x) /*pure*/ nothrow => x.cbrt;
+
+    foreach (f, g; [sin, cos, cube].zip([asin, acos, cbrt]))
         writefln("%6.3f", compose(f, g)(0.5));
 }

Task/First-class-functions/Dart/first-class-functions.dart

@@ -1,13 +1,11 @@
-cube(x) { return x * x * x; }
-inv_cube(x) { return Math.pow(x, 1/3); }
-
-compo(f1, f2) {
-    return func(x) { return f1(f2(x));};
-}
-
-main() {
-    var funcs = [Math.sin,  Math.exp, cube];
-    var invs  = [Math.asin, Math.log, inv_cube];
-    for (int i = 0; i < 3; i++)
-         print(compo(funcs[i], invs[i])(1));
+import 'dart:math' as Math;
+cube(x) => x*x*x;
+cuberoot(x)  => Math.pow(x, 1/3);
+compose(f,g) => ((x)=>f(g(x)));
+main(){
+  var functions = [Math.sin, Math.exp, cube];
+  var inverses = [Math.asin, Math.log, cuberoot];
+  for (int i = 0; i < 3; i++){
+    print(compose(functions[i], inverses[i])(0.5));
+  }
 }

Task/First-class-functions/JavaScript/first-class-functions-1.js

@@ -1,9 +1,9 @@
 // Functions as values of a variable
-var cube = function(x) {
+var cube = function (x) {
   return Math.pow(x, 3);
 };
-var cuberoot = function(x) {
-  return Math.pow(x, 1/3);
+var cuberoot = function (x) {
+  return Math.pow(x, 1 / 3);
 };
 
 // Higher order function

Task/First-class-functions/JavaScript/first-class-functions-2.js

@@ -0,0 +1,17 @@
+// Functions as values of a variable
+var cube = x => Math.pow(x, 3);
+
+var cuberoot = x => Math.pow(x, 1 / 3);
+
+
+// Higher order function
+var compose = (f, g) => (x => f(g(x)));
+
+// Storing functions in a array
+var fun = [ Math.sin, Math.cos, cube ];
+var inv = [ Math.asin, Math.acos, cuberoot ];
+
+for (var i = 0; i < 3; i++) {
+  // Applying the composition to 0.5
+  console.log(compose(inv[i], fun[i])(0.5));
+}

Task/First-class-functions/Perl-6/first-class-functions.pl6

@@ -1,6 +1,6 @@
-sub infix:<⚬> (&#56404;, &#56403;) { -> \x { #56404; #56403; x } }
+sub infix:<∘> (&𝑔, &𝑓) { -> \x { 𝑔 𝑓 x } }
 
-my \#56372; = &sin,  &cos,  { $_ ** <3/1> }
-my \#56373; = &asin, &acos, { $_ ** <1/3> }
+my \𝐴 = &sin,  &cos,  { $_ ** <3/1> }
+my \𝐵 = &asin, &acos, { $_ ** <1/3> }
 
-say .(.5) for #56372; Z⚬ #56373;
+say .(.5) for 𝐴 Z∘ 𝐵