From 4af98a63a231b7ae038b8b38a73404b9e4bef01e Mon Sep 17 00:00:00 2001
From: Remy <remy.haemmerle@daml.com>
Date: Mon, 11 Oct 2021 18:16:05 +0200
Subject: [PATCH] LF: clarify compilation of choice body. (#11195)

* LF: clarify compilation of choice Body.

This is a purely cosmetic choice.

We move up the intro of the choice arg binder to make it clear it
affect the compilation of every expression in the body of a choices (
namely controllers, observers, and update expression).

CHANGELOG_BEGIN
CHANGELOG_END

* formatting
---
 .../digitalasset/daml/lf/speedy/Compiler.scala   | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/daml-lf/interpreter/src/main/scala/com/digitalasset/daml/lf/speedy/Compiler.scala b/daml-lf/interpreter/src/main/scala/com/digitalasset/daml/lf/speedy/Compiler.scala
index 80ab466b045..2ed326844d2 100644
--- a/daml-lf/interpreter/src/main/scala/com/digitalasset/daml/lf/speedy/Compiler.scala
+++ b/daml-lf/interpreter/src/main/scala/com/digitalasset/daml/lf/speedy/Compiler.scala
@@ -991,24 +991,22 @@ private[lf] final class Compiler(
       cidPos: Position,
       mbKey: Option[Position], // defined for byKey operation
       tokenPos: Position,
-  ) = {
+  ) = withEnv { _ =>
     let(
       SBUFetch(
         tmplId
       )(svar(cidPos), mbKey.fold(SEValue.None: SExpr)(pos => SBSome(svar(pos))))
     ) { tmplArgPos =>
       addExprVar(tmpl.param, tmplArgPos)
+      addExprVar(choice.argBinder._1, choiceArgPos)
       let(
         SBUBeginExercise(tmplId, choice.name, choice.consuming, byKey = mbKey.isDefined)(
           svar(choiceArgPos),
-          svar(cidPos), {
-            addExprVar(choice.argBinder._1, choiceArgPos)
-            compile(choice.controllers)
-          }, {
-            choice.choiceObservers match {
-              case Some(observers) => compile(observers)
-              case None => SEValue.EmptyList
-            }
+          svar(cidPos),
+          compile(choice.controllers),
+          choice.choiceObservers match {
+            case Some(observers) => compile(observers)
+            case None => SEValue.EmptyList
           },
         )
       ) { _ =>