Explicitly check type of shared value

1 files changed, 26 insertions, 6 deletions

diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/javatransient0/JavaTransient0Generator.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/javatransient0/JavaTransient0Generator.java
index 92d36e3..9bb72a3 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/javatransient0/JavaTransient0Generator.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/javatransient0/JavaTransient0Generator.java
@@ -1128,8 +1128,7 @@ public class JavaTransient0Generator implements Generator {
                         new JavaExpressionStatement(new JavaBinaryOperation(
                             JavaBinaryOperator.ASSIGN,
                             new JavaRef(target),
-                            new JavaCast(
-                                this.javaGenerator.generateTypeRef(type),
+                            new JavaSwitchExpression(
                                 new JavaMethodCall(
                                     new JavaRef(SHARED_VALUES_NAME),
                                     JavaIdentifier.of("get"),
@@ -1138,6 +1137,23 @@ public class JavaTransient0Generator implements Generator {
                                     // (This doesn't check for negatives, but get() fails for
                                     // negative values anyway.)
                                     List.of(new JavaCast(JavaTypeRef.INT, new JavaRef(id)))
+                                ),
+                                List.of(
+                                    new JavaSwitchRule(
+                                        new JavaCasePattern(new JavaPattern(
+                                            this.javaGenerator.generateTypeRef(type),
+                                            decodedValue
+                                        )),
+                                        new JavaBlock(List.of(
+                                            new JavaYieldStatement(new JavaRef(decodedValue))
+                                        ))
+                                    ),
+                                    new JavaSwitchRule(
+                                        new JavaCaseDefault(),
+                                        new JavaBlock(List.of(
+                                            throwIoException("Shared value was of the wrong type")
+                                        ))
+                                    )
                                 )
                             )
                         ))
@@ -1232,15 +1248,19 @@ public class JavaTransient0Generator implements Generator {
                 new JavaStaticFieldAccess(JavaTypeRef.INT_BOXED, JavaIdentifier.of("MAX_VALUE"))
             ),
             new JavaBlock(List.of(
-                new JavaThrowStatement(new JavaNewExpression(
-                    JavaTypeRef.IO_EXCEPTION,
-                    List.of(new JavaStringLiteral(errorMessage))
-                ))
+                throwIoException(errorMessage)
             )),
             new JavaBlock(List.of())
         );
     }
 
+    private static JavaThrowStatement throwIoException(String errorMessage) {
+        return new JavaThrowStatement(new JavaNewExpression(
+            JavaTypeRef.IO_EXCEPTION,
+            List.of(new JavaStringLiteral(errorMessage))
+        ));
+    }
+
     private JavaPackageName namespaceToJavaTransient0PackageName(NamespaceName namespaceName) {
         return this.javaGenerator.namespaceToJavaPackageName(namespaceName).add(JavaIdentifier.of("transient0"));
     }