STDLIB: Add some helper modules for tuples.

std/tests/tuples_test.ucg

@@ -0,0 +1,12 @@
+import "../tuples.ucg" as tpl;
+import "../testing.ucg" as t;
+
+assert t.asserts{}.equal{
+    left = tpl.fields{tpl={foo=1, bar=2}}.result,
+    right = ["foo", "bar"],
+};
+
+assert t.asserts{}.equal{
+    left = tpl.values{tpl={foo=1, bar=2}}.result,
+    right = [1, 2],
+};

std/tuples.ucg

@@ -0,0 +1,20 @@
+
+let fields = module{
+    tpl = NULL,
+} => {
+    let reducer = macro(acc, field, value) => {
+        result = acc + [field],
+    };
+
+    let result = reduce reducer.result [], (mod.tpl);
+};
+
+let values = module{
+    tpl = NULL,
+} => {
+    let reducer = macro(acc, field, value) => {
+        result = acc + [value],
+    };
+
+    let result = reduce reducer.result [], (mod.tpl);
+};