bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/elaboration/expressions/EFieldAccess.java

   1 package org.simantics.scl.compiler.elaboration.expressions;
   2
   3 import java.util.List;
   4
   5 import org.simantics.scl.compiler.common.names.Names;
   6 import org.simantics.scl.compiler.constants.Constant;
   7 import org.simantics.scl.compiler.elaboration.contexts.SimplificationContext;
   8 import org.simantics.scl.compiler.elaboration.contexts.TranslationContext;
   9 import org.simantics.scl.compiler.elaboration.contexts.TypingContext;
  10 import org.simantics.scl.compiler.elaboration.expressions.EAmbiguous.Alternative;
  11 import org.simantics.scl.compiler.elaboration.expressions.accessor.FieldAccessor;
  12 import org.simantics.scl.compiler.elaboration.expressions.accessor.IdAccessor;
  13 import org.simantics.scl.compiler.errors.Locations;
  14 import org.simantics.scl.compiler.internal.header.ModuleHeader;
  15 import org.simantics.scl.compiler.types.Type;
  16 import org.simantics.scl.compiler.types.Types;
  17 import org.simantics.scl.compiler.types.exceptions.MatchException;
  18
  19 import gnu.trove.map.hash.TObjectIntHashMap;
  20 import gnu.trove.set.hash.THashSet;
  21 import gnu.trove.set.hash.TIntHashSet;
  22
  23 public class EFieldAccess extends SimplifiableExpression {
  24
  25     private static final Type VARIABLE = Types.con("Simantics/Variables", "Variable");
  26
  27     Expression parent;
  28     FieldAccessor accessor;
  29     boolean lastAccessor = true;
  30
  31     public EFieldAccess(Expression parent, FieldAccessor accessor) {
  32         this.parent = parent;
  33         this.accessor = accessor;
  34         if(parent instanceof EFieldAccess)
  35                 ((EFieldAccess)parent).lastAccessor = false;
  36     }
  37
  38     @Override
  39     public void collectVars(TObjectIntHashMap<Variable> allVars,
  40             TIntHashSet vars) {
  41         parent.collectVars(allVars, vars);
  42         accessor.collectVars(allVars, vars);
  43     }
  44
  45     private boolean returnsValue() {
  46         return accessor.accessSeparator == '#' && !accessor.isVariableId();
  47     }
  48
  49     @Override
  50     protected void updateType() throws MatchException {
  51         // Type is already updated in checkBasicType
  52     }
  53
  54     private Expression resolveAccessor(TypingContext context, Type requiredType) {
  55         if(!(accessor instanceof IdAccessor))
  56             return null;
  57         IdAccessor idAccessor = (IdAccessor)accessor;
  58         if(idAccessor.accessSeparator != '.')
  59             return null;
  60         List<Constant> accessors = context.getEnvironment().getFieldAccessors(idAccessor.fieldName);
  61         if(accessors == null) {
  62             context.getErrorLog().log(idAccessor.location, "Couldn't resolve accessor ." + idAccessor.fieldName + ".");
  63             return new EError(location);
  64         }
  65         Expression accessorExpression;
  66         if(accessors.size() == 1)
  67             accessorExpression = new ELiteral(accessors.get(0));
  68         else {
  69             Alternative[] alternatives = new Alternative[accessors.size()];
  70             for(int i=0;i<alternatives.length;++i) {
  71                 final int index = i;
  72                 alternatives[i] = new Alternative() {
  73                     @Override
  74                     public Expression realize() {
  75                         return new ELiteral(accessors.get(index));
  76                     }
  77                     @Override
  78                     public Type getType() {
  79                         return accessors.get(index).getType();
  80                     }
  81                     @Override
  82                     public String toString() {
  83                         return accessors.get(index).toString();
  84                     }
  85                 };
  86             }
  87             accessorExpression = new EAmbiguous(alternatives);
  88             accessorExpression.location = location;
  89         }
  90         return new EApply(location, accessorExpression, parent).checkType(context, requiredType);
  91     }
  92
  93     @Override
  94     public Expression checkBasicType(TypingContext context, Type requiredType) {
  95         ModuleHeader header = context.getCompilationContext().header;
  96         if(header != null && header.fields) {
  97             Expression expression = resolveAccessor(context, requiredType);
  98             if(expression != null)
  99                 return expression;
 100         }
 101
 102         // Default case
 103         if(returnsValue())
 104             setType(requiredType);
 105         else {
 106             setType(VARIABLE);
 107             context.subsume(this, requiredType);
 108         }
 109         parent = parent.checkType(context, VARIABLE);
 110         accessor.checkType(context);
 111         context.declareEffect(getLocation(), Types.READ_GRAPH);
 112         return this;
 113     }
 114
 115     @Override
 116     public void collectFreeVariables(THashSet<Variable> vars) {
 117         parent.collectFreeVariables(vars);
 118         accessor.collectFreeVariables(vars);
 119     }
 120
 121     @Override
 122     public Expression simplify(SimplificationContext context) {
 123         // Simplify subexpressions
 124         parent = parent.simplify(context);
 125         accessor.simplify(context);
 126
 127         if(accessor.accessSeparator == '.')
 128                 return new EApply(
 129                                 getLocation(),
 130                                 Types.READ_GRAPH,
 131                                 context.getConstant(Names.Simantics_Variables_child_),
 132                                 parent,
 133                                 accessor.asExpression()
 134                                 );
 135         else if(!lastAccessor)
 136                 return new EApply(
 137                                 getLocation(),
 138                                 Types.READ_GRAPH,
 139                                 context.getConstant(Names.Simantics_Variables_property),
 140                                 parent,
 141                                 accessor.asExpression()
 142                                 );
 143         else if(accessor.isVariableId())
 144                 return parent;
 145         else
 146                 return new EApply(
 147                                 getLocation(),
 148                                 Types.READ_GRAPH,
 149                                 context.getConstant(Names.Simantics_Variables_untypedPropertyValue, getType()),
 150                                 parent,
 151                                 accessor.asExpression()
 152                                 );
 153     }
 154
 155     @Override
 156     public Expression resolve(TranslationContext context) {
 157         parent = parent.resolve(context);
 158         accessor.resolve(context);
 159         return this;
 160     }
 161
 162     @Override
 163     public void collectEffects(THashSet<Type> effects) {
 164         // FIXME
 165         effects.add(Types.READ_GRAPH);
 166     }
 167
 168     @Override
 169     public void setLocationDeep(long loc) {
 170         if(location == Locations.NO_LOCATION) {
 171             location = loc;
 172             parent.setLocationDeep(loc);
 173             accessor.setLocationDeep(loc);
 174         }
 175     }
 176
 177     @Override
 178     public void accept(ExpressionVisitor visitor) {
 179         visitor.visit(this);
 180     }
 181
 182     @Override
 183     public Expression accept(ExpressionTransformer transformer) {
 184         return transformer.transform(this);
 185     }
 186
 187 }