From 2c28680ca95c042c5b66de6c4b58c8367599cb44 Mon Sep 17 00:00:00 2001 From: Martin Odersky Date: Wed, 11 Apr 2012 18:08:46 -0700 Subject: Implementation of SIP 13 - implicit classes --- .../tools/nsc/typechecker/MethodSynthesis.scala | 89 ++++++++++++++-------- 1 file changed, 58 insertions(+), 31 deletions(-) (limited to 'src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala') diff --git a/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala b/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala index 3d8c2ea564..e622ad7d4b 100644 --- a/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala +++ b/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala @@ -155,28 +155,23 @@ trait MethodSynthesis { /** There are two key methods in here. * - * 1) enterGetterSetter is called from Namer with a ValDef which - * may need accessors. Some setup is performed. In general this - * creates symbols and enters them into the scope of the owner. + * 1) Enter methods such as enterGetterSetterare called + * from Namer with a tree which may generate further trees such as accessors or + * implicit wrappers. Some setup is performed. In general this creates symbols + * and enters them into the scope of the owner. * - * 2) finishGetterSetter is called from Typer when a Template is typed. + * 2) addDerivedTrees is called from Typer when a Template is typed. * It completes the job, returning a list of trees with their symbols - * set to those created in enterGetterSetter. Those trees then become + * set to those created in the enter methods. Those trees then become * part of the typed template. */ trait MethodSynth { self: Namer => import NamerErrorGen._ - - /** TODO - synthesize method. - */ - def enterImplicitClass(tree: ClassDef) { - /** e.g. - val ClassDef(mods, name, tparams, impl) = tree - val converter = ImplicitClassConverter(tree).createAndEnterSymbol() - ... - */ + + def enterImplicitWrapper(tree: ClassDef) { + ImplicitClassWrapper(tree).createAndEnterSymbol() } def enterGetterSetter(tree: ValDef) { @@ -203,7 +198,8 @@ trait MethodSynthesis { enterBeans(tree) } - def finishGetterSetter(typer: Typer, stat: Tree): List[Tree] = stat match { + + def addDerivedTrees(typer: Typer, stat: Tree): List[Tree] = stat match { case vd @ ValDef(mods, name, tpt, rhs) if !noFinishGetterSetter(vd) && !vd.symbol.isLazy => // If we don't save the annotations, they seem to wander off. val annotations = stat.symbol.initialize.annotations @@ -234,35 +230,59 @@ trait MethodSynthesis { field ::: standardAccessors(vd) ::: beanAccessors(vd) } + /** This trait assembles what's needed for synthesizing derived methods. + * Important: Typically, instances of this trait are created TWICE for each derived + * symbol; once form Namers in an enter method, and once from Typers in addDerivedTrees. + * So it's important that creating an instance of Derived does not have a side effect, + * or if it has a side effect, control that it is done only once. + */ trait Derived { - /** The tree from which we are deriving a synthetic member. */ + + /** The tree from which we are deriving a synthetic member. Typically, that's + * given as an argument of the instance. */ def tree: Tree + + /** The name of the method */ def name: TermName + + /** The flags that are retained from the original symbol */ + def flagsMask: Long + + /** The flags that the derived symbol has in addition to those retained from + * the original symbol*/ def flagsExtra: Long - - /** The tree, symbol, and type completer for the synthetic member. */ + + /** type completer for the synthetic member. + */ def completer(sym: Symbol): Type + + /** The derived symbol. It is assumed that this symbol already exists and has been + * entered in the parent scope when derivedSym is called */ def derivedSym: Symbol + + /** The definition tree of the derived symbol. */ def derivedTree: Tree } - + trait DerivedFromMemberDef extends Derived { def tree: MemberDef - + def enclClass: Symbol + // Final methods to make the rest easier to reason about. final def mods = tree.mods final def basisSym = tree.symbol - final def enclClass = basisSym.enclClass final def derivedFlags: Long = basisSym.flags & flagsMask | flagsExtra } - + trait DerivedFromClassDef extends DerivedFromMemberDef { def tree: ClassDef + final def enclClass = basisSym.owner.enclClass } trait DerivedFromValDef extends DerivedFromMemberDef { def tree: ValDef + final def enclClass = basisSym.enclClass /** Which meta-annotation is associated with this kind of entity. * Presently one of: field, getter, setter, beanGetter, beanSetter, param. @@ -334,15 +354,22 @@ trait MethodSynthesis { /** A synthetic method which performs the implicit conversion implied by * the declaration of an implicit class. Yet to be written. */ - case class ImplicitClassConverter(tree: ClassDef) extends DerivedFromClassDef { - def completer(sym: Symbol): Type = ??? - def derivedSym: Symbol = ??? - def derivedTree: DefDef = ??? - def flagsExtra: Long = ??? - def flagsMask: Long = ??? - def name: TermName = ??? - } - + case class ImplicitClassWrapper(tree: ClassDef) extends DerivedFromClassDef { + def completer(sym: Symbol): Type = ??? // not needed + def createAndEnterSymbol(): Symbol = enterSyntheticSym(derivedTree) + def derivedSym: Symbol = { + val result = enclClass.info decl name + assert(result != NoSymbol, "not found: "+name+" in "+enclClass+" "+enclClass.info.decls) + result + } + def derivedTree: DefDef = util.trace("derivedTree = ")( + factoryMeth(mods & flagsMask | flagsExtra, name, tree, symbolic = false) + ) + def flagsExtra: Long = METHOD | IMPLICIT + def flagsMask: Long = AccessFlags + def name: TermName = nme.implicitWrapperName(tree.name) + } + case class Getter(tree: ValDef) extends DerivedGetter { def name = tree.name def category = GetterTargetClass -- cgit v1.2.3