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

   1 package org.simantics.scl.compiler.elaboration.expressions;
   2
   3 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.Just;
   4 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.apply;
   5 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.let;
   6 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.loc;
   7 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.newVar;
   8 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.seq;
   9 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.tuple;
  10 import static org.simantics.scl.compiler.elaboration.expressions.Expressions.var;
  11
  12 import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
  13 import org.simantics.scl.compiler.common.names.Names;
  14 import org.simantics.scl.compiler.elaboration.contexts.SimplificationContext;
  15 import org.simantics.scl.compiler.elaboration.contexts.TranslationContext;
  16 import org.simantics.scl.compiler.elaboration.contexts.TypingContext;
  17 import org.simantics.scl.compiler.elaboration.query.QExists;
  18 import org.simantics.scl.compiler.elaboration.query.Query;
  19 import org.simantics.scl.compiler.elaboration.query.compilation.QueryCompilationContext;
  20 import org.simantics.scl.compiler.elaboration.query.compilation.QueryCompilationMode;
  21 import org.simantics.scl.compiler.elaboration.query.compilation.UnsolvableQueryException;
  22 import org.simantics.scl.compiler.errors.Locations;
  23 import org.simantics.scl.compiler.internal.parsing.parser.SCLTerminals;
  24 import org.simantics.scl.compiler.types.Type;
  25 import org.simantics.scl.compiler.types.Types;
  26 import org.simantics.scl.compiler.types.exceptions.MatchException;
  27 import org.simantics.scl.compiler.types.kinds.Kinds;
  28
  29 import gnu.trove.map.hash.TObjectIntHashMap;
  30 import gnu.trove.set.hash.THashSet;
  31 import gnu.trove.set.hash.TIntHashSet;
  32
  33 public class ESelect extends SimplifiableExpression {
  34
  35     private final Type ARRAY_LIST = Types.con("ArrayList", "T");
  36
  37     int selectVariant;
  38     Expression expression;
  39     Query query;
  40     Variable[] variables;
  41
  42     public ESelect(int selectVariant, Expression expression, Query query) {
  43         this.selectVariant = selectVariant;
  44         this.expression = expression;
  45         this.query = query;
  46     }
  47
  48     @Override
  49     public void collectVars(TObjectIntHashMap<Variable> allVars,
  50             TIntHashSet vars) {
  51         expression.collectVars(allVars, vars);
  52         query.collectVars(allVars, vars);
  53     }
  54
  55     @Override
  56     protected void updateType() throws MatchException {
  57         setType(selectVariant==SCLTerminals.SELECT_FIRST
  58                 ? Types.apply(Types.MAYBE, expression.getType())
  59                 : Types.list(expression.getType()));
  60     }
  61
  62     @Override
  63     public Expression checkBasicType(TypingContext context, Type requiredType) {
  64         Type componentType;
  65         switch(selectVariant) {
  66         case SCLTerminals.SELECT:
  67         case SCLTerminals.SELECT_DISTINCT:
  68             try {
  69                 componentType = Types.unifyApply(Types.LIST, requiredType);
  70             } catch (MatchException e) {
  71                 context.getErrorLog().log(location, "Select expression produces a list of values.");
  72                 return new EError(location);
  73             }
  74             break;
  75         case SCLTerminals.SELECT_FIRST:
  76             try {
  77                 componentType = Types.unifyApply(Types.MAYBE, requiredType);
  78             } catch (MatchException e) {
  79                 context.getErrorLog().log(location, "Select first expression produces an optional value.");
  80                 return new EError(location);
  81             }
  82             break;
  83         default: throw new InternalCompilerError();
  84         }
  85         for(Variable variable : variables)
  86             variable.setType(Types.metaVar(Kinds.STAR));
  87         expression.checkType(context, componentType);
  88         query.checkType(context);
  89
  90         // Compile query
  91         Type elType = expression.getType();
  92         Expression result;
  93         if(selectVariant == SCLTerminals.SELECT_FIRST) {
  94             QueryCompilationContext queryCompilationContext =
  95                     new QueryCompilationContext(context, QueryCompilationMode.GET_FIRST,
  96                             expression.getType(),
  97                             Just(expression));
  98             try {
  99                 new QExists(variables, query).generate(queryCompilationContext);
 100             } catch (UnsolvableQueryException e) {
 101                 context.getErrorLog().log(getLocation(), "Failed to compile the query.\n" + e.getMessage());
 102                 return new EError(getLocation());
 103             }
 104             result = queryCompilationContext.getContinuation();
 105         }
 106         else {
 107             Variable accumulator = newVar("accum", Types.apply(ARRAY_LIST, elType));
 108             result =
 109                     apply(context.getCompilationContext(), Types.PROC, Names.ArrayList_freeze, elType,
 110                             var(accumulator));
 111             Expression innerExpression =
 112                     apply(context.getCompilationContext(), Types.PROC, Names.ArrayList_add, elType,
 113                             var(accumulator), expression);
 114             try {
 115                 QueryCompilationContext queryCompilationContext =
 116                         new QueryCompilationContext(context, QueryCompilationMode.ITERATE, null, innerExpression);
 117                 new QExists(variables, query).generate(queryCompilationContext);
 118                 result = seq(queryCompilationContext.getContinuation(), result);
 119             } catch(UnsolvableQueryException e) {
 120                 context.getErrorLog().log(getLocation(), "Failed to compile the query.\n" + e.getMessage());
 121                 return new EError(getLocation());
 122             }
 123             result = let(accumulator,
 124                     apply(context.getCompilationContext(), Types.PROC, Names.ArrayList_new, elType, tuple()),
 125                     result
 126                     );
 127         }
 128         return loc(location, result);
 129     }
 130
 131     @Override
 132     public void collectFreeVariables(THashSet<Variable> vars) {
 133         expression.collectFreeVariables(vars);
 134         query.collectFreeVariables(vars);
 135         for(Variable variable : variables)
 136             vars.remove(variable);
 137     }
 138
 139     @Override
 140     public Expression resolve(TranslationContext context) {
 141         context.pushExistentialFrame();
 142         expression = expression.resolve(context);
 143         query = query.resolve(context);
 144         variables = context.popExistentialFrame();
 145         return this;
 146     }
 147
 148     @Override
 149     public void setLocationDeep(long loc) {
 150         if(location == Locations.NO_LOCATION) {
 151             location = loc;
 152             expression.setLocationDeep(loc);
 153             query.setLocationDeep(loc);
 154         }
 155     }
 156
 157     @Override
 158     public void accept(ExpressionVisitor visitor) {
 159         visitor.visit(this);
 160     }
 161
 162     @Override
 163     public Expression simplify(SimplificationContext context) {
 164         throw new UnsupportedOperationException();
 165     }
 166
 167     @Override
 168     public Expression accept(ExpressionTransformer transformer) {
 169         return transformer.transform(this);
 170     }
 171
 172 }