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.elaboration.utils.ExpressionDecorator;
  15 import org.simantics.scl.compiler.internal.header.ModuleHeader;
  16 import org.simantics.scl.compiler.types.Type;
  17 import org.simantics.scl.compiler.types.Types;
  18 import org.simantics.scl.compiler.types.exceptions.MatchException;
  19
  20 import gnu.trove.map.hash.TObjectIntHashMap;
  21 import gnu.trove.set.hash.THashSet;
  22 import gnu.trove.set.hash.TIntHashSet;
  23
  24 public class EFieldAccess extends SimplifiableExpression {
  25
  26     private static final Type VARIABLE = Types.con("Simantics/Variables", "Variable");
  27
  28     Expression parent;
  29     FieldAccessor accessor;
  30     boolean lastAccessor = true;
  31
  32     public EFieldAccess(Expression parent, FieldAccessor accessor) {
  33         this.parent = parent;
  34         this.accessor = accessor;
  35         if(parent instanceof EFieldAccess)
  36                 ((EFieldAccess)parent).lastAccessor = false;
  37     }
  38
  39     @Override
  40     public void collectRefs(TObjectIntHashMap<Object> allRefs,
  41             TIntHashSet refs) {
  42         parent.collectRefs(allRefs, refs);
  43         accessor.collectRefs(allRefs, refs);
  44     }
  45
  46     @Override
  47     public void collectVars(TObjectIntHashMap<Variable> allVars,
  48             TIntHashSet vars) {
  49         parent.collectVars(allVars, vars);
  50         accessor.collectVars(allVars, vars);
  51     }
  52
  53     private boolean returnsValue() {
  54         return accessor.accessSeparator == '#' && !accessor.isVariableId();
  55     }
  56
  57     @Override
  58     protected void updateType() throws MatchException {
  59         // Type is already updated in checkBasicType
  60     }
  61
  62     private Expression resolveAccessor(TypingContext context, Type requiredType) {
  63         if(!(accessor instanceof IdAccessor))
  64             return null;
  65         IdAccessor idAccessor = (IdAccessor)accessor;
  66         if(idAccessor.accessSeparator != '.')
  67             return null;
  68         List<Constant> accessors = context.getEnvironment().getFieldAccessors(idAccessor.fieldName);
  69         if(accessors == null) {
  70             context.getErrorLog().log("Couldn't resolve accessor ." + idAccessor.fieldName + ".");
  71             return new EError(location);
  72         }
  73         Expression accessorExpression;
  74         if(accessors.size() == 1)
  75             accessorExpression = new ELiteral(accessors.get(0));
  76         else {
  77             Alternative[] alternatives = new Alternative[accessors.size()];
  78             for(int i=0;i<alternatives.length;++i) {
  79                 final int index = i;
  80                 alternatives[i] = new Alternative() {
  81                     @Override
  82                     public Expression realize() {
  83                         return new ELiteral(accessors.get(index));
  84                     }
  85                     @Override
  86                     public Type getType() {
  87                         return accessors.get(index).getType();
  88                     }
  89                 };
  90             }
  91             accessorExpression = new EAmbiguous(alternatives);
  92         }
  93         return new EApply(location, accessorExpression, parent).checkType(context, requiredType);
  94     }
  95
  96     @Override
  97     public Expression checkBasicType(TypingContext context, Type requiredType) {
  98         ModuleHeader header = context.getCompilationContext().header;
  99         if(header != null && header.fields) {
 100             Expression expression = resolveAccessor(context, requiredType);
 101             if(expression != null)
 102                 return expression;
 103         }
 104
 105         // Default case
 106         if(returnsValue())
 107             setType(requiredType);
 108         else {
 109             setType(VARIABLE);
 110             context.subsume(this, requiredType);
 111         }
 112         parent = parent.checkType(context, VARIABLE);
 113         accessor.checkType(context);
 114         context.declareEffect(getLocation(), Types.READ_GRAPH);
 115         return this;
 116     }
 117
 118     @Override
 119     public void collectFreeVariables(THashSet<Variable> vars) {
 120         parent.collectFreeVariables(vars);
 121         accessor.collectFreeVariables(vars);
 122     }
 123
 124     @Override
 125     public Expression simplify(SimplificationContext context) {
 126         // Simplify subexpressions
 127         parent = parent.simplify(context);
 128         accessor.simplify(context);
 129
 130         if(accessor.accessSeparator == '.')
 131                 return new EApply(
 132                                 getLocation(),
 133                                 Types.READ_GRAPH,
 134                                 context.getConstant(Names.Simantics_Variables_child_),
 135                                 parent,
 136                                 accessor.asExpression()
 137                                 );
 138         else if(!lastAccessor)
 139                 return new EApply(
 140                                 getLocation(),
 141                                 Types.READ_GRAPH,
 142                                 context.getConstant(Names.Simantics_Variables_property),
 143                                 parent,
 144                                 accessor.asExpression()
 145                                 );
 146         else if(accessor.isVariableId())
 147                 return parent;
 148         else
 149                 return new EApply(
 150                                 getLocation(),
 151                                 Types.READ_GRAPH,
 152                                 context.getConstant(Names.Simantics_Variables_untypedPropertyValue, getType()),
 153                                 parent,
 154                                 accessor.asExpression()
 155                                 );
 156     }
 157
 158     @Override
 159     public Expression resolve(TranslationContext context) {
 160         parent = parent.resolve(context);
 161         accessor.resolve(context);
 162         return this;
 163     }
 164
 165     @Override
 166     public Expression decorate(ExpressionDecorator decorator) {
 167         return decorator.decorate(this);
 168     }
 169
 170     @Override
 171     public void collectEffects(THashSet<Type> effects) {
 172         // FIXME
 173         effects.add(Types.READ_GRAPH);
 174     }
 175
 176     @Override
 177     public void setLocationDeep(long loc) {
 178         if(location == Locations.NO_LOCATION) {
 179             location = loc;
 180             parent.setLocationDeep(loc);
 181             accessor.setLocationDeep(loc);
 182         }
 183     }
 184
 185     @Override
 186     public void accept(ExpressionVisitor visitor) {
 187         visitor.visit(this);
 188     }
 189
 190     @Override
 191     public void forVariables(VariableProcedure procedure) {
 192         parent.forVariables(procedure);
 193         accessor.forVariables(procedure);
 194     }
 195
 196     @Override
 197     public Expression accept(ExpressionTransformer transformer) {
 198         return transformer.transform(this);
 199     }
 200
 201 }