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