bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/elaboration/query/pre/QPreGuard.java

   1 package org.simantics.scl.compiler.elaboration.query.pre;
   2
   3 import java.util.Arrays;
   4
   5 import org.simantics.scl.compiler.constants.BooleanConstant;
   6 import org.simantics.scl.compiler.elaboration.contexts.TranslationContext;
   7 import org.simantics.scl.compiler.elaboration.expressions.EApply;
   8 import org.simantics.scl.compiler.elaboration.expressions.EEntityTypeAnnotation;
   9 import org.simantics.scl.compiler.elaboration.expressions.ELiteral;
  10 import org.simantics.scl.compiler.elaboration.expressions.ESimpleLet;
  11 import org.simantics.scl.compiler.elaboration.expressions.EVar;
  12 import org.simantics.scl.compiler.elaboration.expressions.Expression;
  13 import org.simantics.scl.compiler.elaboration.expressions.QueryTransformer;
  14 import org.simantics.scl.compiler.elaboration.expressions.Variable;
  15 import org.simantics.scl.compiler.elaboration.java.CheckRelation;
  16 import org.simantics.scl.compiler.elaboration.query.QAtom;
  17 import org.simantics.scl.compiler.elaboration.query.QMapping;
  18 import org.simantics.scl.compiler.elaboration.query.Query;
  19 import org.simantics.scl.compiler.elaboration.relations.SCLRelation;
  20 import org.simantics.scl.compiler.elaboration.relations.TransitiveClosureRelation;
  21 import org.simantics.scl.compiler.elaboration.rules.MappingRelation;
  22 import org.simantics.scl.compiler.environment.AmbiguousNameException;
  23 import org.simantics.scl.compiler.environment.Environments;
  24 import org.simantics.scl.compiler.errors.Locations;
  25
  26 public class QPreGuard extends PreQuery {
  27     public Expression guard;
  28
  29     public QPreGuard(Expression guard) {
  30         super();
  31         this.guard = guard;
  32     }
  33
  34     private static Query resolveAsQuery(TranslationContext context, Expression function,
  35             Expression[] parameters) {
  36         if(function instanceof EVar) {
  37             String relationName = ((EVar)function).name;
  38             if(relationName.equals("tc") && parameters.length > 0) {
  39                 Query query_ = resolveAsQuery(context, parameters[0],
  40                         Arrays.copyOfRange(parameters, 1, parameters.length));
  41                 if(query_ == null)
  42                     return null;
  43                 if(!(query_ instanceof QAtom)) {
  44                     context.getErrorLog().log(query_.location, "Cannot form a transitive relation.");
  45                     return null;
  46                 }
  47                 QAtom query = (QAtom)query_;
  48                 query.relation = new TransitiveClosureRelation(query.relation);
  49                 return query;
  50             }
  51
  52             MappingRelation mappingRelation;
  53             try {
  54                 mappingRelation = Environments.getMappingRelation(
  55                         context.getEnvironment(), relationName);
  56             } catch (AmbiguousNameException e) {
  57                 context.getErrorLog().log(function.location, e.getMessage());
  58                 return null;
  59             }
  60             if(mappingRelation != null) {
  61                 if(parameters.length != 2)
  62                     context.getErrorLog().log(function.location,
  63                             "An arity of mapping relation should always be 2.");
  64                 for(int i=0;i<parameters.length;++i)
  65                     parameters[i] = parameters[i].resolve(context);
  66                 return new QMapping(mappingRelation, parameters);
  67             }
  68
  69             SCLRelation relation = context.resolveRelation(function.getLocation(), relationName);
  70             if(relation != null) {
  71                 for(int i=0;i<parameters.length;++i)
  72                     parameters[i] = parameters[i].resolve(context);
  73                 return new QAtom(relation, parameters);
  74             }
  75         }
  76         return null;
  77     }
  78
  79     private static Query resolveAsQuery(TranslationContext context, Expression expression) {
  80         if(expression instanceof EApply) {
  81             EApply apply = (EApply)expression;
  82             Query query = resolveAsQuery(context, apply.getFunction(), apply.getParameters());
  83             if(query != null)
  84                 return query;
  85         }
  86         else if(expression instanceof EEntityTypeAnnotation) {
  87             expression = new ESimpleLet(new Variable("_"), expression, new ELiteral(new BooleanConstant(true)));
  88         }
  89         return new QAtom(CheckRelation.INSTANCE,
  90                 new Expression[] { expression.resolve(context) });
  91     }
  92
  93     @Override
  94     public Query resolve(TranslationContext context) {
  95         PreQuery oldPreQuery = context.currentPreQuery;
  96         context.currentPreQuery = this;
  97         Query query = resolveAsQuery(context, guard);
  98         context.currentPreQuery = oldPreQuery;
  99         query.location = location;
 100         return withSideQueries(query);
 101     }
 102
 103     @Override
 104     public void setLocationDeep(long loc) {
 105         if(location == Locations.NO_LOCATION) {
 106             location = loc;
 107             guard.setLocationDeep(loc);
 108         }
 109     }
 110
 111     @Override
 112     public Query accept(QueryTransformer transformer) {
 113         return transformer.transform(this);
 114     }
 115 }