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

   1 package org.simantics.scl.compiler.elaboration.expressions;
   2
   3 import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
   4 import org.simantics.scl.compiler.compilation.CompilationContext;
   5 import org.simantics.scl.compiler.elaboration.contexts.SimplificationContext;
   6 import org.simantics.scl.compiler.elaboration.contexts.TranslationContext;
   7 import org.simantics.scl.compiler.elaboration.contexts.TypingContext;
   8 import org.simantics.scl.compiler.elaboration.modules.SCLValue;
   9 import org.simantics.scl.compiler.errors.Locations;
  10 import org.simantics.scl.compiler.internal.codegen.references.IVal;
  11 import org.simantics.scl.compiler.internal.codegen.writer.CodeWriter;
  12 import org.simantics.scl.compiler.types.Type;
  13 import org.simantics.scl.compiler.types.Types;
  14 import org.simantics.scl.compiler.types.exceptions.MatchException;
  15 import org.simantics.scl.compiler.types.exceptions.UnificationException;
  16 import org.simantics.scl.compiler.types.kinds.Kinds;
  17
  18 import gnu.trove.map.hash.TObjectIntHashMap;
  19 import gnu.trove.set.hash.TIntHashSet;
  20
  21 public class EBind extends SimplifiableExpression {
  22     public Expression pattern;
  23     public Expression value;
  24     public Expression in;
  25     public EVariable monadEvidence;
  26     SCLValue bindFunction;
  27     Type monadType;
  28     Type valueContentType;
  29     Type inContentType;
  30
  31     public EBind(long loc, Expression pattern, Expression value, Expression in) {
  32         super(loc);
  33         this.pattern = pattern;
  34         this.value = value;
  35         this.in = in;
  36     }
  37
  38     public EBind(long loc, Expression pattern, Expression value, Expression in,
  39             SCLValue bindFunction) {
  40         super(loc);
  41         this.pattern = pattern;
  42         this.value = value;
  43         this.in = in;
  44     }
  45
  46     @Override
  47     public void collectVars(TObjectIntHashMap<Variable> allVars,
  48             TIntHashSet vars) {
  49         value.collectVars(allVars, vars);
  50         in.collectVars(allVars, vars);
  51     }
  52
  53     @Override
  54     protected void updateType() throws MatchException {
  55         setType(in.getType());
  56     }
  57
  58     @Override
  59     public Expression checkBasicType(TypingContext context, Type requiredType) {
  60         monadType = Types.metaVar(Kinds.STAR_TO_STAR);
  61         inContentType = Types.metaVar(Kinds.STAR);
  62         Type monadContent = Types.apply(monadType, inContentType);
  63         try {
  64             Types.unify(requiredType, monadContent);
  65         } catch (UnificationException e) {
  66             context.typeError(location, requiredType, monadContent);
  67             return this;
  68         }
  69
  70         Variable variable = new Variable("monadEvidence");
  71         variable.setType(Types.pred(Types.MONAD, monadType));
  72         monadEvidence = new EVariable(getLocation(), variable);
  73         monadEvidence.setType(variable.getType());
  74         context.addConstraintDemand(monadEvidence);
  75
  76         pattern = pattern.checkTypeAsPattern(context, Types.metaVar(Kinds.STAR));
  77         valueContentType = pattern.getType();
  78         value = value.checkType(context, Types.apply(monadType, valueContentType));
  79         in = in.checkType(context, requiredType);
  80         Type inType = in.getType();
  81         setType(inType);
  82         return this;
  83     }
  84
  85     @Override
  86     public IVal toVal(CompilationContext context, CodeWriter w) {
  87         throw new InternalCompilerError("EBind should be eliminated.");
  88     }
  89
  90     /**
  91      * Splits let
  92      */
  93     @Override
  94     public Expression simplify(SimplificationContext context) {
  95         value = value.simplify(context);
  96         in = in.simplify(context);
  97         pattern = pattern.simplify(context);
  98
  99         long loc = getLocation();
 100         Expression simplified = new EApply(loc,
 101                 new EConstant(loc, bindFunction, Types.canonical(monadType), Types.canonical(valueContentType), Types.canonical(inContentType)),
 102                 monadEvidence,
 103                 value,
 104                 new ELambda(loc, new Case[] {
 105                     new Case(new Expression[] { pattern }, in)
 106                 }));
 107         simplified.setType(getType());
 108
 109         return simplified.simplify(context);
 110     }
 111
 112     @Override
 113     public Expression resolve(TranslationContext context) {
 114         value = value.resolve(context);
 115
 116         context.pushFrame();
 117         pattern = pattern.resolveAsPattern(context);
 118         in = in.resolve(context);
 119         context.popFrame();
 120
 121         bindFunction = context.getBindFunction();
 122
 123         return this;
 124     }
 125
 126     @Override
 127     public void setLocationDeep(long loc) {
 128         if(location == Locations.NO_LOCATION) {
 129             location = loc;
 130             pattern.setLocationDeep(loc);
 131             value.setLocationDeep(loc);
 132             in.setLocationDeep(loc);
 133         }
 134     }
 135
 136     @Override
 137     public void accept(ExpressionVisitor visitor) {
 138         visitor.visit(this);
 139     }
 140
 141     @Override
 142     public Expression accept(ExpressionTransformer transformer) {
 143         return transformer.transform(this);
 144     }
 145
 146 }