Change function parameters to type Place

So that we can infer a Capability of Freeze for components

compiler/forget/src/HIR/BuildHIR.ts

@@ -12,7 +12,6 @@ import { invariant } from "../CompilerError";
 import {
   Capability,
   HIRFunction,
-  Identifier,
   IfTerminal,
   InstructionKind,
   InstructionValue,
@@ -55,10 +54,18 @@ export function lower(func: NodePath<t.Function>): HIRFunction {
       ? builder.resolveIdentifier(func.node.id)
       : null;
 
-  const params: Array<Identifier> = [];
+  const params: Array<Place> = [];
   func.node.params.forEach((param) => {
     todoInvariant(t.isIdentifier(param), "todo: support non-identifier params");
-    params.push(builder.resolveIdentifier(param));
+    const identifier = builder.resolveIdentifier(param);
+    const place: Place = {
+      kind: "Identifier",
+      value: identifier,
+      memberPath: null,
+      capability: Capability.Unknown,
+      path: null as any,
+    };
+    params.push(place);
   });
 
   const body = func.get("body");

compiler/forget/src/HIR/Codegen.ts

@@ -50,7 +50,7 @@ export default function codegen(fn: HIRFunction): t.Function {
     t.isFunctionDeclaration(node),
     "todo: handle other than function declaration"
   );
-  const params = fn.params.map((param) => convertIdentifier(param));
+  const params = fn.params.map((param) => convertIdentifier(param.value));
   return t.functionDeclaration(
     fn.id !== null ? convertIdentifier(fn.id) : null,
     params,

compiler/forget/src/HIR/HIR.ts

@@ -39,7 +39,7 @@ import { invariant } from "../CompilerError";
 export type ReactFunction = {
   path: NodePath<t.Function>;
   id: Identifier | null;
-  params: Array<Identifier>;
+  params: Array<Place>;
   returnScope: ScopeId;
   scopes: Map<ScopeId, ReactiveScope>;
 };
@@ -61,7 +61,7 @@ export type ReactiveScope = {
 export type HIRFunction = {
   path: NodePath<t.Function>;
   id: Identifier | null;
-  params: Array<Identifier>;
+  params: Array<Place>;
   body: HIR;
 };
 

compiler/forget/src/HIR/InferReferenceCapability.ts

@@ -86,7 +86,7 @@ export default function inferReferenceCapability(fn: HIRFunction) {
     const place: Place = {
       kind: "Identifier",
       memberPath: null,
-      value: param,
+      value: param.value,
       path: null as any, // TODO
       capability: Capability.Freeze,
     };

compiler/forget/src/HIR/ScopeAnalysis.ts

@@ -64,7 +64,7 @@ export default function analyzeScopes(fn: HIRFunction): ReactFunction {
     inputs: new Set(
       fn.params.map((param) => ({
         kind: "Identifier",
-        value: param,
+        value: param.value,
         memberPath: null,
         capability: Capability.Freeze,
         path: null as any,