bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/internal/deriving/HashableDeriver.java

   1 package org.simantics.scl.compiler.internal.deriving;
   2
   3 import java.util.ArrayList;
   4
   5 import org.simantics.scl.compiler.common.datatypes.Constructor;
   6 import org.simantics.scl.compiler.constants.IntegerConstant;
   7 import org.simantics.scl.compiler.elaboration.errors.NotPatternException;
   8 import org.simantics.scl.compiler.elaboration.expressions.EApply;
   9 import org.simantics.scl.compiler.elaboration.expressions.ELiteral;
  10 import org.simantics.scl.compiler.elaboration.expressions.EVar;
  11 import org.simantics.scl.compiler.elaboration.expressions.Expression;
  12 import org.simantics.scl.compiler.elaboration.modules.TypeConstructor;
  13 import org.simantics.scl.compiler.environment.AmbiguousNameException;
  14 import org.simantics.scl.compiler.environment.Environment;
  15 import org.simantics.scl.compiler.environment.Environments;
  16 import org.simantics.scl.compiler.errors.ErrorLog;
  17 import org.simantics.scl.compiler.internal.parsing.declarations.DDerivingInstanceAst;
  18 import org.simantics.scl.compiler.internal.parsing.declarations.DInstanceAst;
  19 import org.simantics.scl.compiler.internal.parsing.declarations.DValueAst;
  20 import org.simantics.scl.compiler.internal.parsing.expressions.Expressions;
  21 import org.simantics.scl.compiler.internal.parsing.translation.ProcessedDInstanceAst;
  22 import org.simantics.scl.compiler.internal.parsing.translation.ValueRepository;
  23 import org.simantics.scl.compiler.internal.parsing.types.TVarAst;
  24 import org.simantics.scl.compiler.types.TCon;
  25
  26 class HashableDeriver implements InstanceDeriver {
  27
  28     @Override
  29     public void derive(
  30             ErrorLog errorLog,
  31             Environment environment,
  32             ArrayList<ProcessedDInstanceAst> instancesAst,
  33             DDerivingInstanceAst der) {
  34      // Analyze
  35         if(der.types.length != 1) {
  36             errorLog.log(der.location, "Invalid number of parameters to " + der.name);
  37             return;
  38         }
  39         TVarAst headType = DerivingUtils.getHeadType(der.types[0]);
  40         if(headType == null) {
  41             errorLog.log(der.types[0].location, "Cannot derive Hashable instance for the type " + headType + ".");
  42             return;
  43         }
  44         TCon con;
  45         try {
  46             con = Environments.getTypeConstructorName(environment, headType.name);
  47         } catch (AmbiguousNameException e1) {
  48             errorLog.log(headType.location, e1.getMessage());
  49             return;
  50         }
  51         if(con == null) {
  52             errorLog.log(headType.location, "Couldn't resolve " + headType.name);
  53             return;
  54         }
  55         TypeConstructor tcon = environment.getTypeConstructor(con);
  56         if(tcon == null) {
  57             errorLog.log(headType.location, "Didn't find type constructor for " + headType.name);
  58             return;
  59         }
  60         if(tcon.isOpen) {
  61             errorLog.log(headType.location, "Cannot derive instance for open data types.");
  62             return;
  63         }
  64
  65         // Generate
  66         DInstanceAst instanceAst = new DInstanceAst(der.location, der.context, der.name, der.types);
  67         ValueRepository valueDefs = new ValueRepository();
  68         int cId = 0;
  69         for(Constructor constructor : tcon.constructors) {
  70             int l = constructor.parameterTypes.length;
  71             String[] par = new String[l];
  72             for(int i=0;i<l;++i) {
  73                 par[i] = "v" + i;
  74             }
  75             Expression lhs = new EApply(
  76                     new EVar("hashP"),
  77                     new EApply(new EVar(constructor.name.name), Expressions.vars(par)),
  78                     new EVar("accum")
  79                     );
  80             Expression value = new EVar("accum");
  81             for(int i=0;i<l;++i) {
  82                 value = new EApply(new EVar("hashP"),
  83                         new EVar(par[i]),
  84                         value
  85                         );
  86             }
  87             if(tcon.constructors.length > 1)
  88                 value = new EApply(new EVar("hashP"),
  89                         new ELiteral(new IntegerConstant(cId)),
  90                         value
  91                         );
  92
  93             try {
  94                 DValueAst valueAst = new DValueAst(lhs, value);
  95                 valueAst.setLocationDeep(der.location);
  96                 valueDefs.add(valueAst);
  97             } catch (NotPatternException e) {
  98                 errorLog.log(e.getExpression().location, "Not a pattern.");
  99             }
 100             ++ cId;
 101         }
 102         instancesAst.add(new ProcessedDInstanceAst(instanceAst, valueDefs));
 103     }
 104
 105 }