Data commit

Task/First-class-functions/E/first-class-functions-1.e

@@ -0,0 +1,9 @@
+def sin(x)  { return x.sin() }
+def cos(x)  { return x.cos() }
+def asin(x) { return x.asin() }
+def acos(x) { return x.acos() }
+def cube(x) { return x ** 3     }
+def curt(x) { return x ** (1/3) }
+
+def forward := [sin,  cos,  cube]
+def reverse := [asin, acos, curt]

Task/First-class-functions/E/first-class-functions-2.e

@@ -0,0 +1,3 @@
+def compose(f, g) {
+    return fn x { f(g(x)) }
+}

Task/First-class-functions/E/first-class-functions-3.e

@@ -0,0 +1,9 @@
+? def x := 0.5  \
+> for i => f in forward {
+>     def g := reverse[i]
+>     println(`x = $x, f = $f, g = $g, compose($f, $g)($x) = ${compose(f, g)(x)}`)
+> }
+
+x = 0.5, f = <sin>, g = <asin>, compose(<sin>, <asin>)(0.5) = 0.5
+x = 0.5, f = <cos>, g = <acos>, compose(<cos>, <acos>)(0.5) = 0.4999999999999999
+x = 0.5, f = <cube>, g = <curt>, compose(<cube>, <curt>)(0.5) = 0.5000000000000001