From 677c784b6d8ae0e115b7e29bc39f94bc54c36722 Mon Sep 17 00:00:00 2001
From: Daniel Holle <dholle@hb.dhbw-stuttgart.de>
Date: Thu, 17 Aug 2023 13:26:30 +0200
Subject: [PATCH] Allow single expressions in switch expression

---
 resources/bytecode/javFiles/Switch.jav                 | 10 +++++-----
 .../de/dhbwstuttgart/parser/antlr/Java17Parser.g4      |  2 +-
 .../parser/SyntaxTreeGenerator/StatementGenerator.java |  9 +++------
 .../target/tree/expression/TargetYield.java            |  6 ++++++
 4 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/resources/bytecode/javFiles/Switch.jav b/resources/bytecode/javFiles/Switch.jav
index 03308375..9c0e741f 100644
--- a/resources/bytecode/javFiles/Switch.jav
+++ b/resources/bytecode/javFiles/Switch.jav
@@ -7,11 +7,11 @@ record Rec(Integer a, Object b) {}
 public class Switch {
     main(o) {
         return switch (o) {
-        case Rec(Integer a, Integer b) -> { yield a + b; }
-        case Rec(Integer a, Float b) -> { yield a + 10; }
-        case Rec(Integer a, Rec(Integer b, Integer c)) -> { yield a + b + c; }
-        case Integer i -> { yield i; }
-        default -> { yield 0; }
+        case Rec(Integer a, Integer b) -> a + b;
+        case Rec(Integer a, Float b) -> a + 10;
+        case Rec(Integer a, Rec(Integer b, Integer c)) -> a + b + c;
+        case Integer i -> i;
+        default -> 0;
         };
     }
 }
\ No newline at end of file
diff --git a/src/main/antlr4/de/dhbwstuttgart/parser/antlr/Java17Parser.g4 b/src/main/antlr4/de/dhbwstuttgart/parser/antlr/Java17Parser.g4
index d68619cf..d2bdf496 100644
--- a/src/main/antlr4/de/dhbwstuttgart/parser/antlr/Java17Parser.g4
+++ b/src/main/antlr4/de/dhbwstuttgart/parser/antlr/Java17Parser.g4
@@ -725,7 +725,7 @@ guardedPattern
 // Java17
 switchRuleOutcome
     : block
-    | blockStatement*
+    | expression ';'
     ;
 
 classType
diff --git a/src/main/java/de/dhbwstuttgart/parser/SyntaxTreeGenerator/StatementGenerator.java b/src/main/java/de/dhbwstuttgart/parser/SyntaxTreeGenerator/StatementGenerator.java
index ab89d57b..fc75f9f3 100644
--- a/src/main/java/de/dhbwstuttgart/parser/SyntaxTreeGenerator/StatementGenerator.java
+++ b/src/main/java/de/dhbwstuttgart/parser/SyntaxTreeGenerator/StatementGenerator.java
@@ -408,12 +408,9 @@ public class StatementGenerator {
         Block block;
         if (Objects.isNull(outcome.block())) {
             List<Statement> stmts = new ArrayList<>();
-            if (outcome.blockStatement().size() == 1) isSingleExpression = true;
-            outcome.blockStatement().stream().forEach((stmt) -> {
-                stmts.addAll(convert(stmt));
-            });
-            block = new Block(stmts, outcome.blockStatement(0).getStart());
-
+            stmts.add(new Yield(convert(outcome.expression()), outcome.expression().start));
+            isSingleExpression = true;
+            block = new Block(stmts, outcome.expression().getStart());
         } else {
             block = convert(outcome.block(), false);
         }
diff --git a/src/main/java/de/dhbwstuttgart/target/tree/expression/TargetYield.java b/src/main/java/de/dhbwstuttgart/target/tree/expression/TargetYield.java
index 108e7710..10e85bb3 100644
--- a/src/main/java/de/dhbwstuttgart/target/tree/expression/TargetYield.java
+++ b/src/main/java/de/dhbwstuttgart/target/tree/expression/TargetYield.java
@@ -1,4 +1,10 @@
 package de.dhbwstuttgart.target.tree.expression;
 
+import de.dhbwstuttgart.target.tree.type.TargetType;
+
 public record TargetYield(TargetExpression expression) implements TargetExpression {
+    @Override
+    public TargetType type() {
+        return expression.type();
+    }
 }