Family Day update

Task/Map-range/Vala/map-range.vala

@@ -0,0 +1,10 @@
+double map_range(double[] a, double[] b, double s) {
+  return b[0] + ((s - a[0]) * (b[1] - b[0]) / (a[1] - a[0]));
+}
+
+void main() {
+  const double[] r1 = {0.0, 10.0};
+  const double[] r2 = {-1.0, 0.0};
+  for (int s = 0; s < 11; s++)
+    print("%2d maps to %5.2f\n", s, map_range(r1, r2, (double)s));
+}