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