Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.scl.compiler / src / org / simantics / scl / compiler / elaboration / java / EqRelation.java

diff --git a/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/elaboration/java/EqRelation.java b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/elaboration/java/EqRelation.java
new file mode 100644 (file)
index 0000000..7116ed9
--- /dev/null
+++ b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/elaboration/java/EqRelation.java
@@ -0,0 +1,79 @@
+package org.simantics.scl.compiler.elaboration.java;
+
+import org.simantics.scl.compiler.elaboration.expressions.EVariable;
+import org.simantics.scl.compiler.elaboration.expressions.Variable;
+import org.simantics.scl.compiler.elaboration.query.compilation.QueryCompilationContext;
+import org.simantics.scl.compiler.elaboration.relations.AbstractRelation;
+import org.simantics.scl.compiler.types.TVar;
+import org.simantics.scl.compiler.types.Type;
+import org.simantics.scl.compiler.types.Types;
+import org.simantics.scl.compiler.types.kinds.Kinds;
+
+public class EqRelation extends AbstractRelation {
+    public static final EqRelation INSTANCE = new EqRelation();
+    
+    private EqRelation() {}
+    
+    private static final TVar A = Types.var(Kinds.STAR);
+    
+    private static final TVar[] TYPE_VARIABLES = new TVar[] {A};
+    
+    @Override
+    public TVar[] getTypeVariables() {
+        return TYPE_VARIABLES;
+    }
+
+    private static final Type[] PARAMETER_TYPES = new Type[] {A, A};
+    
+    @Override
+    public Type[] getParameterTypes() {
+        return PARAMETER_TYPES;
+    }
+    
+    @Override
+    public int getPhase() {
+        return 0;
+    }
+    
+    @Override
+    public double getSelectivity(int boundVariables) {
+        switch(boundVariables) {
+        case FF: return Double.POSITIVE_INFINITY;
+        case BF:
+        case FB: return 1.0;
+        case BB: return 0.1;
+        default: throw new IllegalArgumentException();
+        }
+    }
+    
+    @Override
+    public int getRequiredVariablesMask() {
+        return FF;
+    }
+
+    @Override
+    public void generate(long location,
+            QueryCompilationContext context,
+            Type[] typeParameters, Variable[] parameters, int boundVariables) {
+        switch(boundVariables) {
+        case BF:
+            context.let(parameters[1], new EVariable(parameters[0]));
+            break;
+        case FB:
+            context.let(parameters[0], new EVariable(parameters[1]));
+            break;
+        case BB:            
+            context.equalityCondition(location, 
+                        new EVariable(parameters[0]),
+                        new EVariable(parameters[1]));
+            break;
+        default: throw new IllegalArgumentException();
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "=";
+    }
+    
+}