2 files changed, 57 insertions, 3 deletions
diff --git a/src/lang/js-lang/builtin/builtin.ts b/src/lang/js-lang/builtin/builtin.ts
index bc40794..a984ca8 100644
--- a/src/lang/js-lang/builtin/builtin.ts
+++ b/src/lang/js-lang/builtin/builtin.ts
@@ -2,9 +2,17 @@ type BUILTIN = (args: any[]) => any;
 
 export const V_BUILTIN_Arr: BUILTIN = (args) => args;
 
-// FIXME actually implement this properly
-export const V_BUILTIN_ToString: BUILTIN = (args) =>
-  args.length === 1 ? JSON.stringify(args[0]) : JSON.stringify(args);
+const toStringInner = (o: any): string => {
+  if (Array.isArray(o)) {
+    return `[${o.map(toStringInner).join(", ")}]`;
+  }
+
+  return o.toString();
+};
+
+export const V_BUILTIN_ToString: BUILTIN = (args) => {
+  return args.length === 1 ? toStringInner(args[0]) : toStringInner(args);
+};
 
 export const V_BUILTIN_Add: BUILTIN = (args) => {
   if (args.every((arg) => ["string", "number"].includes(typeof arg))) {
diff --git a/src/lang/js-lang/builtin/sbuiltin.ts b/src/lang/js-lang/builtin/sbuiltin.ts
index 013854c..60cd117 100644
--- a/src/lang/js-lang/builtin/sbuiltin.ts
+++ b/src/lang/js-lang/builtin/sbuiltin.ts
@@ -40,6 +40,50 @@ export const V_SBUILTIN_Map: SBUILTIN = (node, frame) => {
   return values.map((v, i) => callFn(fn, [v, i], frame));
 };
 
+export const V_SBUILTIN_Reduce: SBUILTIN = (node, frame) => {
+  const children = getEvaluatedChildren(node, frame);
+  const fn = children[1] as FnPrim | undefined;
+  const acc = children[2];
+
+  if (!fn?.fn) {
+    throw new Error(
+      `Invalid params for reduce: ${JSON.stringify(children, undefined, 2)}`
+    );
+  }
+
+  const values = children[0];
+
+  if (!Array.isArray(values)) {
+    // add to ts
+    throw new Error(`Can't reduce non-array value: ${values}`);
+  }
+
+  return values.reduce(
+    (acc, cur, idx) => callFn(fn, [acc, cur, idx], frame),
+    acc
+  );
+};
+
+export const V_SBUILTIN_Filter: SBUILTIN = (node, frame) => {
+  const children = getEvaluatedChildren(node, frame);
+  const fn = children[1] as FnPrim | undefined;
+
+  if (!fn?.fn) {
+    throw new Error(
+      `Invalid params for filter: ${JSON.stringify(children, undefined, 2)}`
+    );
+  }
+
+  const values = children[0];
+
+  if (!Array.isArray(values)) {
+    // add to ts
+    throw new Error(`Can't filter non-array value: ${values}`);
+  }
+
+  return values.filter((v, idx) => callFn(fn, [v, idx], frame) === true);
+};
+
 export const V_SBUILTIN_IfElse: SBUILTIN = (node, frame) => {
   const children = node.children;
 
@@ -59,5 +103,7 @@ export const V_SBUILTIN_IfElse: SBUILTIN = (node, frame) => {
 export const nameToSBUILTIN: Record<string, SBUILTIN> = {
   call: V_SBUILTIN_Call,
   map: V_SBUILTIN_Map,
+  reduce: V_SBUILTIN_Reduce,
+  filter: V_SBUILTIN_Filter,
   "?": V_SBUILTIN_IfElse,
 };