bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/elaboration/chr/translation/CHRTranslation.java

   1 package org.simantics.scl.compiler.elaboration.chr.translation;\r
   2 \r
   3 import java.util.ArrayList;\r
   4 import java.util.Arrays;\r
   5 \r
   6 import org.simantics.scl.compiler.elaboration.chr.CHRLiteral;\r
   7 import org.simantics.scl.compiler.elaboration.chr.CHRQuery;\r
   8 import org.simantics.scl.compiler.elaboration.chr.CHRRule;\r
   9 import org.simantics.scl.compiler.elaboration.chr.relations.CHRConstraint;\r
  10 import org.simantics.scl.compiler.elaboration.chr.relations.SpecialCHRRelation;\r
  11 import org.simantics.scl.compiler.elaboration.chr.relations.UnresolvedCHRRelation;\r
  12 import org.simantics.scl.compiler.elaboration.contexts.TranslationContext;\r
  13 import org.simantics.scl.compiler.elaboration.expressions.EApply;\r
  14 import org.simantics.scl.compiler.elaboration.expressions.EBinary;\r
  15 import org.simantics.scl.compiler.elaboration.expressions.EVar;\r
  16 import org.simantics.scl.compiler.elaboration.expressions.Expression;\r
  17 import org.simantics.scl.compiler.elaboration.expressions.block.CHRStatement;\r
  18 import org.simantics.scl.compiler.elaboration.expressions.block.ConstraintStatement;\r
  19 import org.simantics.scl.compiler.elaboration.expressions.list.ListAssignment;\r
  20 import org.simantics.scl.compiler.elaboration.expressions.list.ListGenerator;\r
  21 import org.simantics.scl.compiler.elaboration.expressions.list.ListGuard;\r
  22 import org.simantics.scl.compiler.elaboration.expressions.list.ListQualifier;\r
  23 import org.simantics.scl.compiler.environment.AmbiguousNameException;\r
  24 import org.simantics.scl.compiler.environment.Environments;\r
  25 import org.simantics.scl.compiler.errors.Locations;\r
  26 import org.simantics.scl.compiler.internal.parsing.types.TypeAst;\r
  27 \r
  28 public class CHRTranslation {\r
  29 \r
  30     private static CHRLiteral convertExpression(boolean isHead, Expression expression) {\r
  31         if(isHead)\r
  32             return new CHRLiteral(expression.location, SpecialCHRRelation.CHECK, new Expression[] {expression}, false, false);\r
  33         else\r
  34             return new CHRLiteral(expression.location, SpecialCHRRelation.EXECUTE, new Expression[] {expression}, false, false);\r
  35     }\r
  36 \r
  37     private static CHRLiteral convertConstraint(boolean remove, boolean negated, Expression expression) {\r
  38         ArrayList<Expression> parameters = new ArrayList<Expression>(4);\r
  39         while(expression instanceof EApply) {\r
  40             EApply apply = (EApply)expression;\r
  41             for(int i=apply.parameters.length-1;i>=0;--i)\r
  42                 parameters.add(apply.parameters[i]);\r
  43             expression = apply.function;\r
  44         }\r
  45         EVar var = (EVar)expression;\r
  46         Expression[] parametersArray = new Expression[parameters.size()];\r
  47         for(int i=0,j=parametersArray.length-1;i<parametersArray.length;++i,--j)\r
  48             parametersArray[i] = parameters.get(j);\r
  49         return new CHRLiteral(expression.location, new UnresolvedCHRRelation(var.location, var.name), parametersArray, remove, negated);\r
  50     }\r
  51     \r
  52     private static CHRLiteral convertListQualifier(TranslationContext context, boolean isHead, ListQualifier qualifier) {\r
  53         if(qualifier instanceof ListGuard) {\r
  54             Expression originalExpression = ((ListGuard)qualifier).condition;\r
  55             if(originalExpression instanceof EVar && ((EVar)originalExpression).name.equals("True"))\r
  56                 return null;\r
  57             Expression currentExpression = originalExpression;\r
  58             boolean remove = false;\r
  59             boolean negated = false;\r
  60             if(currentExpression instanceof EBinary) {\r
  61                 EBinary binary = (EBinary)currentExpression;\r
  62                 if(binary.negation==null || !binary.rights.isEmpty())\r
  63                     return convertExpression(isHead, originalExpression);\r
  64                 currentExpression = binary.left;\r
  65                 remove = true;\r
  66             }\r
  67             else if(currentExpression instanceof EApply) {\r
  68                 EApply apply = (EApply)currentExpression;\r
  69                 if(apply.function instanceof EVar && ((EVar)apply.function).name.equals("not")) {\r
  70                     negated = true;\r
  71                     if(apply.parameters.length == 1)\r
  72                         currentExpression = apply.parameters[0];\r
  73                     else {\r
  74                         currentExpression = new EApply(\r
  75                                 Locations.combine(apply.parameters[0].location, apply.parameters[apply.parameters.length-1].location),\r
  76                                 apply.parameters[0],\r
  77                                 Arrays.copyOfRange(apply.parameters, 1, apply.parameters.length));\r
  78                     }\r
  79                 }\r
  80             }\r
  81             if(isConstraint(context, currentExpression))\r
  82                 return convertConstraint(remove, negated, currentExpression);\r
  83             else\r
  84                 return convertExpression(isHead, originalExpression);\r
  85         }\r
  86         else if(qualifier instanceof ListAssignment) {\r
  87             ListAssignment assignment = (ListAssignment)qualifier;\r
  88             return new CHRLiteral(assignment.location, SpecialCHRRelation.EQUALS, new Expression[] {\r
  89                     assignment.pattern, assignment.value \r
  90             }, false, false);\r
  91         }\r
  92         else if(qualifier instanceof ListGenerator) {\r
  93             ListGenerator generator = (ListGenerator)qualifier;\r
  94             return new CHRLiteral(generator.location, SpecialCHRRelation.MEMBER, new Expression[] {\r
  95                     generator.pattern, generator.value\r
  96             }, false, false);\r
  97         }\r
  98         else {\r
  99             context.getErrorLog().log(qualifier.location, "Invalid CHR literal.");\r
 100             return null;\r
 101         }\r
 102     }\r
 103     \r
 104     private static boolean isConstraint(TranslationContext context, Expression expression) {\r
 105         while(expression instanceof EApply)\r
 106             expression = ((EApply)expression).function;\r
 107         if(!(expression instanceof EVar))\r
 108             return false;\r
 109         String name = ((EVar)expression).name;\r
 110         if(TranslationContext.isConstructorName(name))\r
 111             return true;\r
 112         try {\r
 113             return Environments.getRelation(context.getEnvironment(), name) != null;\r
 114         } catch (AmbiguousNameException e) {\r
 115             return true;\r
 116         }\r
 117     }\r
 118 \r
 119     public static CHRRule convertCHRStatement(TranslationContext context, CHRStatement statement) {\r
 120         ArrayList<CHRLiteral> head = new ArrayList<CHRLiteral>(statement.head.length);\r
 121         for(ListQualifier qualifier : statement.head) {\r
 122             CHRLiteral literal = convertListQualifier(context, true, qualifier);\r
 123             if(literal != null)\r
 124                 head.add(literal);\r
 125         }\r
 126         ArrayList<CHRLiteral> body = new ArrayList<CHRLiteral>(statement.body.length);\r
 127         for(ListQualifier qualifier : statement.body) {\r
 128             CHRLiteral literal = convertListQualifier(context, false, qualifier);\r
 129             if(literal != null)\r
 130                 body.add(literal);\r
 131         }\r
 132         return new CHRRule(statement.location,\r
 133                 new CHRQuery(head.toArray(new CHRLiteral[head.size()])),\r
 134                 new CHRQuery(body.toArray(new CHRLiteral[body.size()])),\r
 135                 null);\r
 136     }\r
 137 \r
 138     public static CHRConstraint convertConstraintStatement(TranslationContext context, ConstraintStatement statement) {\r
 139         return new CHRConstraint(statement.location, statement.name.text, TypeAst.toTypes(context, statement.parameterTypes));\r
 140     }\r
 141     \r
 142 }\r