From e37df8aad861bee6f0be10d271837223a0b3bccd Mon Sep 17 00:00:00 2001
From: Xie Yuheng <xyheme@gmail.com>
Date: Fri, 17 Nov 2023 17:32:07 +0800
Subject: [PATCH] up

---
 TODO.md                                | 2 ++
 src/lang/evaluate/evaluate.ts          | 4 ++++
 src/lang/evaluate/evaluateBlockStmt.ts | 3 +++
 src/lang/execute/execute.ts            | 2 ++
 4 files changed, 11 insertions(+)

diff --git a/TODO.md b/TODO.md
index c1f4554..e166132 100644
--- a/TODO.md
+++ b/TODO.md
@@ -3,6 +3,8 @@ DefineDatatype & DatatypeDefinition
 - `datatype <name>` -- to define trivial type for now
 - pass parser `tests/`
 
+`Begin` -- should call react
+
 # net
 
 [net] react.test.ts
diff --git a/src/lang/evaluate/evaluate.ts b/src/lang/evaluate/evaluate.ts
index e541f00..34f9a01 100644
--- a/src/lang/evaluate/evaluate.ts
+++ b/src/lang/evaluate/evaluate.ts
@@ -6,10 +6,14 @@ import { Value } from "../value"
 import { evaluateBlock } from "./evaluateBlock"
 import { evaluateDefinition } from "./evaluateDefinition"
 
+// `EvaluateOptions` can be used to denote different modes of evaluation.
+
 export interface EvaluateOptions {
   //
 }
 
+// We return `Array<Value>` to handle possible multiple return values.
+
 export function evaluate(
   mod: Mod,
   env: Env,
diff --git a/src/lang/evaluate/evaluateBlockStmt.ts b/src/lang/evaluate/evaluateBlockStmt.ts
index b1a6e80..411afbb 100644
--- a/src/lang/evaluate/evaluateBlockStmt.ts
+++ b/src/lang/evaluate/evaluateBlockStmt.ts
@@ -12,6 +12,9 @@ import { Value, assertValueKind } from "../value"
 import { EvaluateOptions } from "./evaluate"
 import { evaluateOne } from "./evaluateOne"
 
+// We use `null` to denote that this `BlockStmt`
+// should not be viewed as returned results of this block.
+
 export function evaluateBlockStmt(
   mod: Mod,
   env: Env,
diff --git a/src/lang/execute/execute.ts b/src/lang/execute/execute.ts
index 786f975..5ea7643 100644
--- a/src/lang/execute/execute.ts
+++ b/src/lang/execute/execute.ts
@@ -3,6 +3,8 @@ import { EvaluateOptions, evaluateBlock, evaluateParameters } from "../evaluate"
 import { Mod, define } from "../mod"
 import { Stmt } from "../stmt"
 
+// We return `null` to late the type checker catch the uncovered switch cases.
+
 export async function execute(mod: Mod, stmt: Stmt): Promise<null> {
   try {
     const options: EvaluateOptions = {}