diff options
Diffstat (limited to 'sources/scalac/typechecker/DeSugarize.java')
| -rw-r--r-- | sources/scalac/typechecker/DeSugarize.java | 87 |
1 files changed, 83 insertions, 4 deletions
diff --git a/sources/scalac/typechecker/DeSugarize.java b/sources/scalac/typechecker/DeSugarize.java index 15c5713293..cc6654232f 100644 --- a/sources/scalac/typechecker/DeSugarize.java +++ b/sources/scalac/typechecker/DeSugarize.java @@ -5,7 +5,6 @@ ** ** ** $Id$ \* */ - package scalac.typechecker; import java.io.*; @@ -49,6 +48,10 @@ public class DeSugarize implements Kinds, Modifiers { */ protected final FreshNameCreator freshNameCreator; + /** the tree duplicator + */ + final Transformer duplicator; + /** the constructor */ public DeSugarize(Analyzer analyzer, Global global) { @@ -58,9 +61,9 @@ public class DeSugarize implements Kinds, Modifiers { this.gen = analyzer.gen; this.infer = analyzer.infer; this.freshNameCreator = global.freshNameCreator; + this.duplicator = analyzer.duplicator; } - // Auxiliary definitions and functions ------------------------------------------- /** introduce fresh variable of the form "deS$56" @@ -217,7 +220,83 @@ public class DeSugarize implements Kinds, Modifiers { global.definitions.functionType(targs1, targs[targs1.length])); print(tree, "postfun", result); return result; - } else return tree; + } else { + print(tree, "postfun", tree); + return tree; + } + } + + /** Cases, Argtpe, Restpe ==> + * (new scala.PartialFunction[Argtpe, Restpe] { + * def apply(x: Argtpe): Restpe = x match {Cases} + * def isDefinedAt(x: Argtpe): scala.Boolean = x match {Cases'} + * }: scala.PartialFunction[Argtpe, +Restpe]) + * WHERE + * case P1 if G1 => E1, ..., Pn if Gn => En) = Cases + * Cases' = case P1 if G1 => True, ..., Pn if Gn => True, _ => False + * Argtpe = targs[0] + * Restpe = targs[1] + */ + public Tree partialFunction(Tree tree, Type[] targs) { + Type argtpe = targs[0]; + Type restpe = targs[1].dropVariance(); + Tree constr = make.TypeApply(tree.pos, + make.Select(tree.pos, + make.Ident(tree.pos, Names.scala), + Names.PartialFunction.toConstrName()), + new Tree[]{gen.mkType(tree.pos, argtpe), gen.mkType(tree.pos, restpe)}); + Name x = getvar(); + ValDef param = (ValDef) make.ValDef( + tree.pos, PARAM, x, gen.mkType(tree.pos, argtpe), Tree.Empty); + ValDef[][] vparams = new ValDef[][]{new ValDef[]{param}}; + Tree body = make.Apply(tree.pos, + make.Select(tree.pos, + make.Ident(tree.pos, x), Names.match), new Tree[]{tree}); + Tree applyDef = make.DefDef( + tree.pos, 0, Names.apply, Tree.ExtTypeDef.EMPTY_ARRAY, vparams, + gen.mkType(tree.pos, restpe), body); + Tree tree1 = isDefinedAtVisitor(tree); + Tree body1 = make.Apply(tree.pos, + make.Select(tree.pos, + make.Ident(tree.pos, x), Names.match), new Tree[]{tree1}); + Tree isDefinedAtDef = make.DefDef( + tree.pos, 0, Names.isDefinedAt, Tree.ExtTypeDef.EMPTY_ARRAY, + duplicator.transform(vparams), + gen.mkType(tree.pos, global.definitions.BOOLEAN_TYPE), body1); + Tree newTree = make.New(tree.pos, + make.Template( + tree.pos, new Tree[]{constr}, new Tree[]{applyDef, isDefinedAtDef})); + Tree result = make.Typed(tree.pos, + tree, + gen.mkType(tree.pos, + global.definitions.partialFunctionType(targs[0], targs[1]))); + print(tree, "partialfun", result); + return result; + } + + private Tree isDefinedAtVisitor(Tree tree) { + switch (tree) { + case Visitor(CaseDef[] cases): + CaseDef[] cases1 = new CaseDef[cases.length + 1]; + for (int i = 0; i < cases.length; i++) { + switch (cases[i]) { + case CaseDef(Tree pat, Tree guard, _): + cases1[i] = (CaseDef) make.CaseDef(cases[i].pos, + duplicator.transform(pat), + duplicator.transform(guard), + make.Select(tree.pos, + make.Ident(tree.pos, Names.scala), Names.True)); + } + } + cases1[cases.length] = (CaseDef) make.CaseDef(tree.pos, + make.Ident(tree.pos, Names.WILDCARD), + Tree.Empty, + make.Select(tree.pos, + make.Ident(tree.pos, Names.scala), Names.False)); + return make.Visitor(tree.pos, cases1); + default: + throw new ApplicationError("visitor expected", tree); + } } /** match => this.match @@ -247,7 +326,7 @@ public class DeSugarize implements Kinds, Modifiers { case Visitor(CaseDef[] cases): Name x = getvar(); ValDef param = (ValDef) make.ValDef( - tree.pos, 0, x, Tree.Empty, Tree.Empty); + tree.pos, PARAM, x, Tree.Empty, Tree.Empty); Tree xuse = make.Ident(tree.pos, x); // x.match {cases} Tree body = make.Apply(tree.pos, |