+package org.simantics.scl.compiler.constants.singletons;\r
+\r
+import org.objectweb.asm.Label;\r
+import org.simantics.scl.compiler.constants.Constant;\r
+import org.simantics.scl.compiler.internal.codegen.continuations.Cont;\r
+import org.simantics.scl.compiler.internal.codegen.references.IVal;\r
+import org.simantics.scl.compiler.internal.codegen.utils.MethodBuilder;\r
+import org.simantics.scl.compiler.internal.codegen.utils.TransientClassBuilder;\r
+import org.simantics.scl.compiler.types.TVar;\r
+import org.simantics.scl.compiler.types.Types;\r
+import org.simantics.scl.compiler.types.kinds.Kinds;\r
+\r
+public class NothingConstant extends Constant {\r
+ \r
+ private static final TVar A = Types.var(Kinds.STAR);\r
+ public static final NothingConstant INSTANCE = new NothingConstant();\r
+ \r
+ private NothingConstant() {\r
+ super(Types.forAll(A, Types.apply(Types.MAYBE, A)));\r
+ }\r
+\r
+ @Override\r
+ public void push(MethodBuilder mb) {\r
+ mb.loadNull();\r
+ }\r
+ \r
+ @Override\r
+ public void deconstruct(MethodBuilder mb, IVal parameter,\r
+ Cont success, Label failure) {\r
+ if(failure != null) { \r
+ parameter.push(mb);\r
+ mb.ifNullBranch(failure, false);\r
+ }\r
+ mb.jump(success);\r
+ }\r
+ \r
+ public int constructorTag() {\r
+ return 0;\r
+ }\r
+ \r
+ @Override\r
+ public String toString() {\r
+ return "Nothing";\r
+ }\r
+ \r
+ @Override\r
+ public Object realizeValue(TransientClassBuilder classBuilder) { \r
+ return null;\r
+ }\r
+}\r