bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/internal/deriving/EqDeriver.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.elaboration.errors.NotPatternException;
   7 import org.simantics.scl.compiler.elaboration.expressions.EApply;
   8 import org.simantics.scl.compiler.elaboration.expressions.EVar;
   9 import org.simantics.scl.compiler.elaboration.expressions.EVariable;
  10 import org.simantics.scl.compiler.elaboration.expressions.Expression;
  11 import org.simantics.scl.compiler.elaboration.expressions.Variable;
  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 EqDeriver 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 Eq 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         for(Constructor constructor : tcon.constructors) {
  69             int l = constructor.parameterTypes.length;
  70             String[] par1 = new String[l];
  71             String[] par2 = new String[l];
  72             for(int i=0;i<l;++i) {
  73                 par1[i] = "a" + i;
  74                 par2[i] = "b" + i;
  75             }
  76             Expression lhs = new EApply(
  77                     new EVar("=="),
  78                     new EApply(new EVar(constructor.name.name), Expressions.vars(par1)),
  79                     new EApply(new EVar(constructor.name.name), Expressions.vars(par2))
  80                     );
  81             Expression value = new EVar("True");
  82             for(int i=l-1;i>=0;--i)
  83                 value = new EApply(
  84                         new EVar("&&"),
  85                         new EApply(
  86                                 new EVar("=="),
  87                                 new EVar(par1[i]),
  88                                 new EVar(par2[i])),
  89                         value);
  90             try {
  91                 DValueAst valueAst = new DValueAst(lhs, value);
  92                 valueAst.setLocationDeep(der.location);
  93                 valueDefs.add(valueAst);
  94             } catch (NotPatternException e) {
  95                 errorLog.log(e.getExpression().location, "Not a pattern.");
  96             }
  97         }
  98         {
  99             Expression lhs = new EApply(
 100                     new EVar("=="),
 101                     new EVariable(new Variable("_")),
 102                     new EVariable(new Variable("_")));
 103             Expression value = new EVar("False");
 104             try {
 105                 DValueAst valueAst = new DValueAst(lhs, value);
 106                 valueAst.setLocationDeep(der.location);
 107                 valueDefs.add(valueAst);
 108                 /*valueDefs.addAnnotation("==", new DAnnotationAst(new EVar("@private"),
 109                         Collections.<Expression>emptyList()));*/
 110             } catch (NotPatternException e) {
 111                 errorLog.log(e.getExpression().location, "Not a pattern.");
 112             }
 113         }
 114         instancesAst.add(new ProcessedDInstanceAst(instanceAst, valueDefs));
 115     }
 116
 117 }