Data commit

Task/Church-numerals/Octave/church-numerals.octave

@@ -0,0 +1,24 @@
+zero = @(f) @(x) x;
+succ = @(n) @(f) @(x) f(n(f)(x));
+add = @(m, n) @(f) @(x) m(f)(n(f)(x));
+mul = @(m, n) @(f) @(x) m(n(f))(x);
+pow = @(b, e) e(b);
+
+% Need a short-circuiting ternary
+iif = @(varargin) varargin{3 - varargin{1}}();
+
+% Helper for anonymous recursion
+% The branches are thunked to prevent infinite recursion
+to_church_ = @(f, i) iif(i == 0, @() zero, @() succ(f(f, i - 1)));
+to_church = @(i) to_church_(to_church_, i);
+
+to_int = @(c) c(@(n) n + 1)(0);
+
+three = succ(succ(succ(zero)));
+four = succ(succ(succ(succ(zero))));
+
+cellfun(to_int, {
+    add(three, four),
+    mul(three, four),
+    pow(three, four),
+    pow(four, three)})