feat(transducers): add sortedKeys() iterator

thi-ng · Dec 26, 2019 · fa9343c · fa9343c
1 parent 1bc561b
commit fa9343c
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diff --git a/packages/transducers/src/index.ts b/packages/transducers/src/index.ts
@@ -123,6 +123,7 @@ export * from "./iter/range3d";
 export * from "./iter/repeat";
 export * from "./iter/repeatedly";
 export * from "./iter/reverse";
+export * from "./iter/sorted-keys";
 export * from "./iter/symmetric";
 export * from "./iter/tween";
 export * from "./iter/vals";

diff --git a/packages/transducers/src/iter/sorted-keys.ts b/packages/transducers/src/iter/sorted-keys.ts
@@ -0,0 +1,14 @@
+import { Comparator } from "@thi.ng/api";
+import { compare } from "@thi.ng/compare";
+
+/**
+ * Syntax sugar for `Object.keys(x).sort()` with support for custom
+ * comparator (default: {@link @thi.ng/compare#compare}) and yielding
+ * iterator of sorted keys.
+ *
+ * @param x -
+ * @param cmp -
+ */
+export function* sortedKeys(x: any, cmp: Comparator<string> = compare) {
+    yield* Object.keys(x).sort(cmp);
+}