feat(parse): add replace/xfReplace() xform

thi-ng · Aug 17, 2020 · 7291181 · 7291181
1 parent 5e994d0
commit 7291181
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diff --git a/packages/parse/src/index.ts b/packages/parse/src/index.ts
@@ -49,5 +49,6 @@ export * from "./xform/join";
 export * from "./xform/nest";
 export * from "./xform/number";
 export * from "./xform/print";
+export * from "./xform/replace";
 export * from "./xform/trim";
 export * from "./xform/with-id";
diff --git a/packages/parse/src/xform/replace.ts b/packages/parse/src/xform/replace.ts
@@ -0,0 +1,23 @@
+import type { Parser, ScopeTransform } from "../api";
+import { xform } from "../combinators/xform";
+
+/**
+ * HOF scope transform which replaces a node's result with given pre-configured
+ * value and discards node's children. Also see {@link replace}.
+ *
+ * @param result - replacement value
+ */
+export const xfReplace = <T>(result: any): ScopeTransform<T> => (scope) => {
+    scope!.result = result;
+    scope!.children = null;
+    return scope;
+};
+
+/**
+ * Syntax sugar for `xform(parser, xfReplace(result))`.
+ *
+ * @param parser -
+ * @param result -
+ */
+export const replace = <T>(parser: Parser<T>, result: any) =>
+    xform(parser, xfReplace(result));