bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/internal/elaboration/constraints/ConstraintEnvironment.java

   1 package org.simantics.scl.compiler.internal.elaboration.constraints;
   2
   3 import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
   4 import org.simantics.scl.compiler.constants.ClassConstant;
   5 import org.simantics.scl.compiler.constants.StringConstant;
   6 import org.simantics.scl.compiler.elaboration.expressions.EApply;
   7 import org.simantics.scl.compiler.elaboration.expressions.EConstant;
   8 import org.simantics.scl.compiler.elaboration.expressions.ELiteral;
   9 import org.simantics.scl.compiler.elaboration.java.Builtins;
  10 import org.simantics.scl.compiler.elaboration.modules.TypeClass;
  11 import org.simantics.scl.compiler.elaboration.modules.TypeClassInstance;
  12 import org.simantics.scl.compiler.environment.Environment;
  13 import org.simantics.scl.compiler.errors.Locations;
  14 import org.simantics.scl.compiler.types.TApply;
  15 import org.simantics.scl.compiler.types.TCon;
  16 import org.simantics.scl.compiler.types.TFun;
  17 import org.simantics.scl.compiler.types.TPred;
  18 import org.simantics.scl.compiler.types.TUnion;
  19 import org.simantics.scl.compiler.types.TVar;
  20 import org.simantics.scl.compiler.types.Type;
  21 import org.simantics.scl.compiler.types.Types;
  22
  23 import gnu.trove.map.hash.THashMap;
  24
  25 public class ConstraintEnvironment {
  26     Environment environment;
  27
  28     public ConstraintEnvironment(Environment environment) {
  29         this.environment = environment;
  30     }
  31
  32     public Superconstraint[] getSuperconstraints(TPred constraint) {
  33         TypeClass tc = environment.getTypeClass(constraint.typeClass);
  34         if(tc == null) {
  35             throw new InternalCompilerError("Didn't find constraint " + constraint + ". Maybe Prelude is not loaded?");
  36         }
  37         if(tc.context.length == 0)
  38             return Superconstraint.EMPTY_ARRAY;
  39         Superconstraint[] result = new Superconstraint[tc.context.length];
  40         for(int i=0;i<result.length;++i) {
  41             result[i] = new Superconstraint(
  42                     (TPred)tc.context[i].replace(tc.parameters, constraint.parameters),
  43                     tc.superGenerators[i]
  44                     );
  45         }
  46         return result;
  47     }
  48
  49     public Reduction reduce(TPred constraint) {
  50         // VecComp
  51         if(constraint.typeClass == Types.VEC_COMP) {
  52             Type parameter = Types.canonical(constraint.parameters[0]);
  53             if(parameter.isGround())
  54                 return new Reduction(new ELiteral(new ClassConstant(Types.pred(Types.VEC_COMP, parameter), parameter)),
  55                         Type.EMPTY_ARRAY, TPred.EMPTY_ARRAY);
  56         }
  57         // Serializable
  58         if(constraint.typeClass == Types.SERIALIZABLE)
  59             return ReduceSerializable.reduceSerializable(constraint.parameters[0]);
  60
  61         // Typeable
  62         else if(constraint.typeClass == Types.TYPEABLE) {
  63             Type parameter = Types.canonical(constraint.parameters[0]);
  64             if(parameter instanceof TCon) {
  65                 TCon con = (TCon)parameter;
  66                 return new Reduction(
  67                         new EApply(Locations.NO_LOCATION,
  68                                 new EConstant(Builtins.INSTANCE.getValue("TCon")),
  69                                 new ELiteral(new StringConstant(con.module)),
  70                                 new ELiteral(new StringConstant(con.name))),
  71                                 Type.EMPTY_ARRAY, TPred.EMPTY_ARRAY);
  72             }
  73             else if(parameter instanceof TApply) {
  74                 TApply apply = (TApply)parameter;
  75                 return new Reduction(
  76                         new EConstant(Builtins.INSTANCE.getValue("TApply")),
  77                         Type.EMPTY_ARRAY, new TPred[] {
  78                             Types.pred(Types.TYPEABLE, apply.function),
  79                             Types.pred(Types.TYPEABLE, apply.parameter),
  80                         });
  81             }
  82             else if(parameter instanceof TFun) {
  83                 TFun fun = (TFun)parameter;
  84                 return new Reduction(
  85                         new EConstant(Builtins.INSTANCE.getValue("TFun")),
  86                         Type.EMPTY_ARRAY, new TPred[] {
  87                             Types.pred(Types.TYPEABLE, fun.domain),
  88                             Types.pred(Types.TYPEABLE, fun.effect),
  89                             Types.pred(Types.TYPEABLE, fun.range)
  90                         });
  91             }
  92             else if(parameter instanceof TUnion) {
  93                 TUnion union = (TUnion)parameter;
  94
  95                 /*TPred[] demands = new TPred[union.effects.length];
  96                 for(int i=0;i<union.effects.length;++i)
  97                     demands[i] = Types.pred(Types.TYPEABLE, union.effects[i]);*/
  98                 if(union.effects.length == 0)
  99                 return new Reduction(
 100                             new EConstant(Builtins.INSTANCE.getValue("TPure")),
 101                             Type.EMPTY_ARRAY,
 102                             TPred.EMPTY_ARRAY);
 103             }
 104         }
 105
 106         // Standard case
 107         THashMap<TVar, Type> substitution = new THashMap<TVar, Type>();
 108         for(TypeClassInstance inst : environment.getInstances(constraint.typeClass)) {
 109             if(Types.match(inst.instance, constraint, substitution)) {
 110                 TPred[] demands = new TPred[inst.context.length];
 111                 for(int i=0;i<demands.length;++i) {
 112                     demands[i] = (TPred)inst.context[i].replace(substitution);
 113                 }
 114                 Type[] parameters = new Type[inst.generatorParameters.length];
 115                 for(int i=0;i<parameters.length;++i) {
 116                     Type parameter = substitution.get(inst.generatorParameters[i]);
 117                     if(parameter == null)
 118                         parameter = inst.generatorParameters[i]; // TODO Is this correct?
 119                     parameters[i] = parameter;
 120                 }
 121                 return new Reduction(new ELiteral(inst.generator), parameters, demands);
 122             }
 123             else
 124                 substitution.clear();
 125         }
 126         return null;
 127     }
 128 }