Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.scl.compiler / src / org / simantics / scl / compiler / elaboration / query / compilation / ExpressionConstraint.java

diff --git a/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/elaboration/query/compilation/ExpressionConstraint.java b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/elaboration/query/compilation/ExpressionConstraint.java
new file mode 100644 (file)
index 0000000..0c7c21e
--- /dev/null
+++ b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/elaboration/query/compilation/ExpressionConstraint.java
@@ -0,0 +1,114 @@
+package org.simantics.scl.compiler.elaboration.query.compilation;\r
+\r
+import gnu.trove.map.hash.THashMap;\r
+import gnu.trove.procedure.TObjectObjectProcedure;\r
+import gnu.trove.set.hash.TIntHashSet;\r
+\r
+import java.util.ArrayList;\r
+\r
+import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;\r
+import org.simantics.scl.compiler.elaboration.contexts.ReplaceContext;\r
+import org.simantics.scl.compiler.elaboration.expressions.EVariable;\r
+import org.simantics.scl.compiler.elaboration.expressions.Expression;\r
+import org.simantics.scl.compiler.elaboration.expressions.Variable;\r
+import org.simantics.scl.compiler.errors.Locations;\r
+import org.simantics.scl.compiler.types.TVar;\r
+import org.simantics.scl.compiler.types.Type;\r
+\r
+public class ExpressionConstraint extends QueryConstraint {\r
+    Variable variable;\r
+    Expression expression;\r
+    boolean isPattern;\r
+    \r
+    long forwardVariableMask;\r
+    long backwardVariableMask;\r
+    \r
+    ArrayList<Variable> globalVariables;\r
+    \r
+    public ExpressionConstraint(final ConstraintCollectionContext context, Variable variable,\r
+            Expression expression, boolean isPattern) {\r
+        this.variable = variable;\r
+        this.expression = expression;\r
+        this.isPattern = isPattern;\r
+        \r
+        final TIntHashSet vars = new TIntHashSet();\r
+        expression.collectVars(context.getVariableMap(), vars);\r
+        \r
+        int var1 = context.variableMap.get(variable);\r
+        vars.add(var1);\r
+        backwardVariableMask = 1L << var1;\r
+        \r
+        variables = vars.toArray();\r
+        \r
+        for(int v : variables)\r
+            forwardVariableMask |= 1L << v;\r
+        forwardVariableMask ^= backwardVariableMask;\r
+        \r
+        this.globalVariables = context.variables;\r
+    }\r
+    \r
+    private boolean canBeSolvedForwards(long boundVariables) {\r
+        return (forwardVariableMask & boundVariables) == forwardVariableMask;\r
+    }\r
+    \r
+    private boolean canBeSolvedBackwards(long boundVariables) {\r
+        return (backwardVariableMask & boundVariables) == backwardVariableMask;\r
+    }\r
+    \r
+    @Override\r
+    public boolean canBeSolvedFrom(long boundVariables) {\r
+        return canBeSolvedForwards(boundVariables) || (isPattern && canBeSolvedBackwards(boundVariables));  \r
+    }\r
+    \r
+    @Override\r
+    public double getSolutionCost(long boundVariables) {\r
+        return 1.0;\r
+    }\r
+    \r
+    @Override\r
+    public double getSolutionBranching(long boundVariables) {\r
+        if(canBeSolvedForwards(boundVariables))\r
+            return (boundVariables&1)==0 ? 1.0 : 0.95;\r
+        else if(isPattern && canBeSolvedBackwards(boundVariables))\r
+            return 0.95;\r
+        else\r
+            return Double.POSITIVE_INFINITY;\r
+    }\r
+    \r
+    @Override\r
+    public void generate(final QueryCompilationContext context) {\r
+        if(canBeSolvedForwards(finalBoundVariables)) {\r
+            if(canBeSolvedBackwards(finalBoundVariables))\r
+                context.equalityCondition(expression.location, new EVariable(variable), expression);\r
+            else\r
+                context.let(variable, expression);\r
+        }\r
+        else if(canBeSolvedBackwards(finalBoundVariables)) {\r
+            Expression pattern = expression;\r
+            \r
+            long mask = forwardVariableMask & finalBoundVariables;\r
+            THashMap<Variable, Expression> map = new THashMap<Variable, Expression>();\r
+            if(mask != 0L) {\r
+                for(int variableId : variables)\r
+                    if( ((mask >> variableId)&1L) == 1L ) {\r
+                        Variable original = globalVariables.get(variableId);\r
+                        Variable newVariable = new Variable(original.getName() + "_temp", original.getType());\r
+                        map.put(original, new EVariable(newVariable));\r
+                    }\r
+                \r
+                ReplaceContext replaceContext = new ReplaceContext(new THashMap<TVar,Type>(0), map, context.getTypingContext());\r
+                pattern = pattern.replace(replaceContext);\r
+            }\r
+            context.match(pattern, new EVariable(variable), true);\r
+            map.forEachEntry(new TObjectObjectProcedure<Variable, Expression>() {\r
+                @Override\r
+                public boolean execute(Variable a, Expression b) {\r
+                    context.equalityCondition(Locations.NO_LOCATION, new EVariable(a), b);\r
+                    return true;\r
+                }\r
+            });\r
+        }\r
+        else\r
+            throw new InternalCompilerError(expression.location, "Error happened when tried to solve the query.");\r
+    }\r
+}\r