/* NSC -- new Scala compiler
* Copyright 2005-2011 LAMP/EPFL
* @author Martin Odersky
*/
package scala.tools.nsc
package interpreter
import scala.collection.{ mutable, immutable }
import scala.PartialFunction.cond
import scala.reflect.NameTransformer
import util.Chars
trait MemberHandlers {
val intp: IMain
import intp.{ Request, global, naming }
import global._
import naming._
def string2codeQuoted(str: String) = "\"" + string2code(str) + "\""
/** Convert a string into code that can recreate the string.
* This requires replacing all special characters by escape
* codes. It does not add the surrounding " marks. */
def string2code(str: String): String = {
val res = new StringBuilder
for (c <- str) c match {
case '"' | '\'' | '\\' => res += '\\' ; res += c
case _ if c.isControl => res ++= Chars.char2uescape(c)
case _ => res += c
}
res.toString
}
def any2stringOf(x: Any, maxlen: Int) =
"scala.runtime.ScalaRunTime.stringOf(%s, %s)".format(x, maxlen)
private def codegenln(leadingPlus: Boolean, xs: String*): String = codegen(leadingPlus, (xs ++ Array("\n")): _*)
private def codegenln(xs: String*): String = codegenln(true, xs: _*)
private def codegen(xs: String*): String = codegen(true, xs: _*)
private def codegen(leadingPlus: Boolean, xs: String*): String = {
val front = if (leadingPlus) "+ " else ""
front + (xs map string2codeQuoted mkString " + ")
}
private implicit def name2string(name: Name) = name.toString
/** A traverser that finds all mentioned identifiers, i.e. things
* that need to be imported. It might return extra names.
*/
private class ImportVarsTraverser extends Traverser {
val importVars = new mutable.HashSet[Name]()
override def traverse(ast: Tree) = ast match {
case Ident(name) =>
// XXX this is obviously inadequate but it's going to require some effort
// to get right.
if (name.toString startsWith "x$") ()
else importVars += name
case _ => super.traverse(ast)
}
}
private object ImportVarsTraverser {
def apply(member: Tree) = {
val ivt = new ImportVarsTraverser()
ivt traverse member
ivt.importVars.toList
}
}
def chooseHandler(member: Tree): MemberHandler = member match {
case member: DefDef => new DefHandler(member)
case member: ValDef => new ValHandler(member)
case member@Assign(Ident(_), _) => new AssignHandler(member)
case member: ModuleDef => new ModuleHandler(member)
case member: ClassDef => new ClassHandler(member)
case member: TypeDef => new TypeAliasHandler(member)
case member: Import => new ImportHandler(member)
case DocDef(_, documented) => chooseHandler(documented)
case member => new GenericHandler(member)
}
sealed abstract class MemberDefHandler(override val member: MemberDef) extends MemberHandler(member) {
def name: Name = member.name
def mods: Modifiers = member.mods
def keyword = member.keyword
def prettyName = NameTransformer.decode(name)
override def definesImplicit = member.mods.isImplicit
override def definesTerm: Option[TermName] = Some(name.toTermName) filter (_ => name.isTermName)
override def definesType: Option[TypeName] = Some(name.toTypeName) filter (_ => name.isTypeName)
}
/** Class to handle one member among all the members included
* in a single interpreter request.
*/
sealed abstract class MemberHandler(val member: Tree) {
def tpe = member.tpe
def definesImplicit = false
def definesValue = false
def isLegalTopLevel = member match {
case _: ModuleDef | _: ClassDef | _: Import => true
case _ => false
}
def definesTerm = Option.empty[TermName]
def definesType = Option.empty[TypeName]
lazy val referencedNames = ImportVarsTraverser(member)
def importedNames = List[Name]()
def definedNames = definesTerm.toList ++ definesType.toList
def definedOrImported = definedNames ++ importedNames
def extraCodeToEvaluate(req: Request): String = ""
def resultExtractionCode(req: Request): String = ""
private def shortName = this.getClass.toString split '.' last
override def toString = shortName + referencedNames.mkString(" (refs: ", ", ", ")")
}
class GenericHandler(member: Tree) extends MemberHandler(member)
class ValHandler(member: ValDef) extends MemberDefHandler(member) {
val maxStringElements = 1000 // no need to mkString billions of elements
def stringOf(x: Any) = any2stringOf(x, maxStringElements)
override def definesValue = true
override def resultExtractionCode(req: Request): String = {
val isInternal = isUserVarName(name) && req.lookupTypeOf(name) == "Unit"
if (!mods.isPublic || isInternal) ""
else {
// if this is a lazy val we avoid evaluating it here
val resultString =
if (mods.isLazy) codegenln(false, "<lazy>")
else stringOf(req fullPath name)
""" + "%s: %s = " + %s""".format(prettyName, string2code(req typeOf name), resultString)
}
}
}
class DefHandler(member: DefDef) extends MemberDefHandler(member) {
private def vparamss = member.vparamss
// true if 0-arity
override def definesValue = vparamss.isEmpty || vparamss.head.isEmpty
override def resultExtractionCode(req: Request) =
if (mods.isPublic) codegenln(name, ": ", req.typeOf(name)) else ""
}
class AssignHandler(member: Assign) extends MemberHandler(member) {
val lhs = member.lhs.asInstanceOf[Ident] // an unfortunate limitation
val name = newTermName(freshInternalVarName())
override def definesTerm = Some(name)
override def definesValue = true
override def extraCodeToEvaluate(req: Request) =
"""val %s = %s""".format(name, lhs)
/** Print out lhs instead of the generated varName */
override def resultExtractionCode(req: Request) = {
val lhsType = string2code(req lookupTypeOf name)
val res = string2code(req fullPath name)
""" + "%s: %s = " + %s + "\n" """.format(lhs, lhsType, res) + "\n"
}
}
class ModuleHandler(module: ModuleDef) extends MemberDefHandler(module) {
override def definesTerm = Some(name)
override def definesValue = true
override def resultExtractionCode(req: Request) = codegenln("defined module ", name)
}
class ClassHandler(member: ClassDef) extends MemberDefHandler(member) {
override def definesType = Some(name.toTypeName)
override def definesTerm = Some(name.toTermName) filter (_ => mods.isCase)
override def resultExtractionCode(req: Request) =
codegenln("defined %s %s".format(keyword, name))
}
class TypeAliasHandler(member: TypeDef) extends MemberDefHandler(member) {
private def isAlias = mods.isPublic && treeInfo.isAliasTypeDef(member)
override def definesType = Some(name.toTypeName) filter (_ => isAlias)
override def resultExtractionCode(req: Request) =
codegenln("defined type alias ", name) + "\n"
}
class ImportHandler(imp: Import) extends MemberHandler(imp) {
val Import(expr, selectors) = imp
def targetType = intp.typeOfExpression("" + expr)
private def selectorWild = selectors filter (_.name == nme.USCOREkw) // wildcard imports, e.g. import foo._
private def selectorRenames = selectors map (_.rename) filterNot (_ == null)
/** Whether this import includes a wildcard import */
val importsWildcard = selectorWild.nonEmpty
/** Complete list of names imported by a wildcard */
def wildcardImportedNames: List[Name] = (
for (tpe <- targetType ; if importsWildcard) yield
tpe.nonPrivateMembers filter (x => x.isMethod && x.isPublic) map (_.name) distinct
).toList.flatten
/** The individual names imported by this statement */
/** XXX come back to this and see what can be done with wildcards now that
* we know how to enumerate the identifiers.
*/
override lazy val importedNames: List[Name] =
selectorRenames filterNot (_ == nme.USCOREkw) flatMap (_.bothNames)
override def resultExtractionCode(req: Request) = codegenln(imp.toString) + "\n"
}
}
