tasks a-s

Task/Optional-parameters/D/optional-parameters.d

@@ -0,0 +1,28 @@
+import std.stdio, std.algorithm, std.functional;
+
+string[][] sortTable(string[][] table,
+                     in bool function(string[],string[]) ordering=null,
+                     in int column = 0,
+                     in bool reverse = false) {
+    if (ordering is null)
+        table.schwartzSort!(row => row[column])();
+    else
+        table.sort!ordering();
+    if (reverse)
+        table.reverse();
+    return table;
+}
+
+void main() {
+    auto data = [["a", "b", "c"],
+                 ["", "q", "z"],
+                 ["zap", "zip", "Zot"]];
+
+    alias show = curry!(writefln, "%-(%s\n%)\n");
+    show(data);
+    show(sortTable(data));
+    show(sortTable(data, null, 2));
+    show(sortTable(data, null, 1));
+    show(sortTable(data, null, 1, true));
+    show(sortTable(data, (a,b) => b.length > a.length));
+}