[λ] Remove unused params in FunctionExpression

compiler/forget/src/HIR/BuildHIR.ts

@@ -1359,33 +1359,15 @@ function lowerExpression(
         };
       }
       loweredFunc = lowering.unwrap();
-
-      let hasError = false;
-      const params: Array<string> = [];
-      for (const p of expr.get("params")) {
-        if (!p.isIdentifier()) {
-          builder.errors.push({
-            reason: `(BuildHIR::lowerExpression) Handle ${p.type} params in FunctionExpression`,
-            severity: ErrorSeverity.Todo,
-            nodePath: p,
-          });
-          hasError = true;
-          continue;
-        }
-        params.push(p.node.name);
-      }
-      return hasError
-        ? { kind: "UnsupportedNode", node: exprNode, loc: exprLoc }
-        : {
-            kind: "FunctionExpression",
-            name,
-            params,
-            loweredFunc,
-            dependencies: captured.refs,
-            mutatedDeps: [],
-            expr: expr.node,
-            loc: exprLoc,
-          };
+      return {
+        kind: "FunctionExpression",
+        name,
+        loweredFunc,
+        dependencies: captured.refs,
+        mutatedDeps: [],
+        expr: expr.node,
+        loc: exprLoc,
+      };
     }
     case "TaggedTemplateExpression": {
       const expr = exprPath as NodePath<t.TaggedTemplateExpression>;

compiler/forget/src/HIR/HIR.ts

@@ -469,7 +469,6 @@ export type JsxAttribute =
 export type FunctionExpression = {
   kind: "FunctionExpression";
   name: string | null;
-  params: Array<string>;
   dependencies: Array<Place>;
   // TODO(gsn): Remove this mutatedDeps array and use dependencies as single
   // source of truth.

compiler/forget/src/HIR/PrintHIR.ts

@@ -333,14 +333,11 @@ export function printInstructionValue(instrValue: ReactiveValue): string {
       break;
     }
     case "FunctionExpression": {
-      const params = instrValue.params.join(",");
-      const body = generate(instrValue.expr).code;
+      const fn = generate(instrValue.expr).code;
       const deps = instrValue.dependencies
         .map((i) => printIdentifier(i.identifier))
         .join(",");
-      value = `Function ${instrValue.name ?? ""} @deps[${deps}] (${
-        params ?? ""
-      }){${body}}`;
+      value = `Function @deps[${deps}]{${fn}}`;
       break;
     }
     case "TaggedTemplateExpression": {

compiler/forget/src/ReactiveScopes/CodegenReactiveFunction.ts

@@ -673,7 +673,6 @@ function codegenInstructionValue(
     case "FunctionExpression": {
       const id =
         instrValue.name !== null ? t.identifier(instrValue.name) : null;
-      const params = instrValue.params.map((p) => t.identifier(p));
       value = instrValue.expr;
       break;
     }