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Diffstat (limited to 'src/compiler/scala/tools/nsc/interpreter/JLineCompletion.scala')
| -rw-r--r-- | src/compiler/scala/tools/nsc/interpreter/JLineCompletion.scala | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/src/compiler/scala/tools/nsc/interpreter/JLineCompletion.scala b/src/compiler/scala/tools/nsc/interpreter/JLineCompletion.scala new file mode 100644 index 0000000000..3f2003a2f7 --- /dev/null +++ b/src/compiler/scala/tools/nsc/interpreter/JLineCompletion.scala @@ -0,0 +1,346 @@ +/* NSC -- new Scala compiler + * Copyright 2005-2011 LAMP/EPFL + * @author Paul Phillips + */ + +package scala.tools.nsc +package interpreter + +import scala.tools.jline._ +import scala.tools.jline.console.completer._ +import java.util.{ List => JList } +import util.returning +import Completion._ + +// REPL completor - queries supplied interpreter for valid +// completions based on current contents of buffer. +class JLineCompletion(val intp: IMain) extends Completion with CompletionOutput { + val global: intp.global.type = intp.global + import global._ + import definitions.{ PredefModule, RootClass, AnyClass, AnyRefClass, ScalaPackage, JavaLangPackage } + type ExecResult = Any + + // verbosity goes up with consecutive tabs + private var verbosity: Int = 0 + def resetVerbosity() = verbosity = 0 + + def isCompletionDebug = intp.isCompletionDebug + def DBG(msg: => Any) = if (isCompletionDebug) println(msg.toString) + def debugging[T](msg: String): T => T = (res: T) => returning[T](res)(x => DBG(msg + x)) + + // XXX not yet used. + lazy val dottedPaths = { + def walk(tp: Type): scala.List[Symbol] = { + val pkgs = tp.nonPrivateMembers filter (_.isPackage) + pkgs ++ (pkgs map (_.tpe) flatMap walk) + } + walk(RootClass.tpe) + } + + def getType(name: String, isModule: Boolean) = { + val f = if (isModule) definitions.getModule(_: Name) else definitions.getClass(_: Name) + try Some(f(name).tpe) + catch { case _: MissingRequirementError => None } + } + + def typeOf(name: String) = getType(name, false) + def moduleOf(name: String) = getType(name, true) + + trait CompilerCompletion { + def tp: Type + def effectiveTp = tp match { + case MethodType(Nil, resType) => resType + case NullaryMethodType(resType) => resType + case _ => tp + } + + // for some reason any's members don't show up in subclasses, which + // we need so 5.<tab> offers asInstanceOf etc. + private def anyMembers = AnyClass.tpe.nonPrivateMembers + def anyRefMethodsToShow = List("isInstanceOf", "asInstanceOf", "toString") + + def tos(sym: Symbol) = sym.name.decode.toString + def memberNamed(s: String) = members find (x => tos(x) == s) + def hasMethod(s: String) = methods exists (x => tos(x) == s) + + // XXX we'd like to say "filterNot (_.isDeprecated)" but this causes the + // compiler to crash for reasons not yet known. + def members = (effectiveTp.nonPrivateMembers ++ anyMembers) filter (_.isPublic) + def methods = members filter (_.isMethod) + def packages = members filter (_.isPackage) + def aliases = members filter (_.isAliasType) + + def memberNames = members map tos + def methodNames = methods map tos + def packageNames = packages map tos + def aliasNames = aliases map tos + } + + object TypeMemberCompletion { + def apply(tp: Type): TypeMemberCompletion = { + if (tp.typeSymbol.isPackageClass) new PackageCompletion(tp) + else new TypeMemberCompletion(tp) + } + def imported(tp: Type) = new ImportCompletion(tp) + } + + class TypeMemberCompletion(val tp: Type) extends CompletionAware + with CompilerCompletion { + def excludeEndsWith: List[String] = Nil + def excludeStartsWith: List[String] = List("<") // <byname>, <repeated>, etc. + def excludeNames: List[String] = + anyref.methodNames.filterNot(anyRefMethodsToShow contains) ++ List("_root_") + + def methodSignatureString(sym: Symbol) = { + def asString = new MethodSymbolOutput(sym).methodString() + atPhase(currentRun.typerPhase)(asString) + } + + def exclude(name: String): Boolean = ( + (name contains "$") || + (excludeNames contains name) || + (excludeEndsWith exists (name endsWith _)) || + (excludeStartsWith exists (name startsWith _)) + ) + def filtered(xs: List[String]) = xs filterNot exclude distinct + + def completions(verbosity: Int) = + debugging(tp + " completions ==> ")(filtered(memberNames)) + + override def follow(s: String): Option[CompletionAware] = + debugging(tp + " -> '" + s + "' ==> ")(memberNamed(s) map (x => TypeMemberCompletion(x.tpe))) + + override def alternativesFor(id: String): List[String] = + debugging(id + " alternatives ==> ") { + val alts = members filter (x => x.isMethod && tos(x) == id) map methodSignatureString + + if (alts.nonEmpty) "" :: alts else Nil + } + + override def toString = "TypeMemberCompletion(%s)".format(tp) + } + + class PackageCompletion(tp: Type) extends TypeMemberCompletion(tp) { + override def excludeNames = anyref.methodNames + } + + class LiteralCompletion(lit: Literal) extends TypeMemberCompletion(lit.value.tpe) { + override def completions(verbosity: Int) = verbosity match { + case 0 => filtered(memberNames) + case _ => memberNames + } + } + + class ImportCompletion(tp: Type) extends TypeMemberCompletion(tp) { + override def completions(verbosity: Int) = verbosity match { + case 0 => filtered(members filterNot (_.isSetter) map tos) + case _ => super.completions(verbosity) + } + } + + // not for completion but for excluding + object anyref extends TypeMemberCompletion(AnyRefClass.tpe) { } + + // the unqualified vals/defs/etc visible in the repl + object ids extends CompletionAware { + override def completions(verbosity: Int) = intp.unqualifiedIds :+ "classOf" + // we try to use the compiler and fall back on reflection if necessary + // (which at present is for anything defined in the repl session.) + override def follow(id: String) = + if (completions(0) contains id) { + for (clazz <- intp clazzForIdent id) yield { + // XXX The isMemberClass check is a workaround for the crasher described + // in the comments of #3431. The issue as described by iulian is: + // + // Inner classes exist as symbols + // inside their enclosing class, but also inside their package, with a mangled + // name (A$B). The mangled names should never be loaded, and exist only for the + // optimizer, which sometimes cannot get the right symbol, but it doesn't care + // and loads the bytecode anyway. + // + // So this solution is incorrect, but in the short term the simple fix is + // to skip the compiler any time completion is requested on a nested class. + if (clazz.isMemberClass) new InstanceCompletion(clazz) + else (typeOf(clazz.getName) map TypeMemberCompletion.apply) getOrElse new InstanceCompletion(clazz) + } + } + else None + } + + // wildcard imports in the repl like "import global._" or "import String._" + private def imported = intp.wildcardImportedTypes map TypeMemberCompletion.imported + + // literal Ints, Strings, etc. + object literals extends CompletionAware { + def simpleParse(code: String): Tree = { + val unit = new CompilationUnit(new util.BatchSourceFile("<console>", code)) + val scanner = new syntaxAnalyzer.UnitParser(unit) + val tss = scanner.templateStatSeq(false)._2 + + if (tss.size == 1) tss.head else EmptyTree + } + + def completions(verbosity: Int) = Nil + + override def follow(id: String) = simpleParse(id) match { + case x: Literal => Some(new LiteralCompletion(x)) + case _ => None + } + } + + // top level packages + object rootClass extends TypeMemberCompletion(RootClass.tpe) { } + // members of Predef + object predef extends TypeMemberCompletion(PredefModule.tpe) { + override def excludeEndsWith = super.excludeEndsWith ++ List("Wrapper", "ArrayOps") + override def excludeStartsWith = super.excludeStartsWith ++ List("wrap") + override def excludeNames = anyref.methodNames + + override def exclude(name: String) = super.exclude(name) || ( + (name contains "2") + ) + + override def completions(verbosity: Int) = verbosity match { + case 0 => Nil + case _ => super.completions(verbosity) + } + } + // members of scala.* + object scalalang extends PackageCompletion(ScalaPackage.tpe) { + def arityClasses = List("Product", "Tuple", "Function") + def skipArity(name: String) = arityClasses exists (x => name != x && (name startsWith x)) + override def exclude(name: String) = super.exclude(name) || ( + skipArity(name) + ) + + override def completions(verbosity: Int) = verbosity match { + case 0 => filtered(packageNames ++ aliasNames) + case _ => super.completions(verbosity) + } + } + // members of java.lang.* + object javalang extends PackageCompletion(JavaLangPackage.tpe) { + override lazy val excludeEndsWith = super.excludeEndsWith ++ List("Exception", "Error") + override lazy val excludeStartsWith = super.excludeStartsWith ++ List("CharacterData") + + override def completions(verbosity: Int) = verbosity match { + case 0 => filtered(packageNames) + case _ => super.completions(verbosity) + } + } + + // the list of completion aware objects which should be consulted + lazy val topLevelBase: List[CompletionAware] = List(ids, rootClass, predef, scalalang, javalang, literals) + def topLevel = topLevelBase ++ imported + + // the first tier of top level objects (doesn't include file completion) + def topLevelFor(parsed: Parsed) = topLevel flatMap (_ completionsFor parsed) + + // the most recent result + def lastResult = Forwarder(() => ids follow intp.mostRecentVar) + + def lastResultFor(parsed: Parsed) = { + /** The logic is a little tortured right now because normally '.' is + * ignored as a delimiter, but on .<tab> it needs to be propagated. + */ + val xs = lastResult completionsFor parsed + if (parsed.isEmpty) xs map ("." + _) else xs + } + + // chasing down results which won't parse + def execute(line: String): Option[ExecResult] = { + val parsed = Parsed(line) + def noDotOrSlash = line forall (ch => ch != '.' && ch != '/') + + if (noDotOrSlash) None // we defer all unqualified ids to the repl. + else { + (ids executionFor parsed) orElse + (rootClass executionFor parsed) orElse + (FileCompletion executionFor line) + } + } + + // generic interface for querying (e.g. interpreter loop, testing) + def completions(buf: String): List[String] = + topLevelFor(Parsed.dotted(buf + ".", buf.length + 1)) + + def completer() = new JLineCompleterClass + + /** This gets a little bit hairy. It's no small feat delegating everything + * and also keeping track of exactly where the cursor is and where it's supposed + * to end up. The alternatives mechanism is a little hacky: if there is an empty + * string in the list of completions, that means we are expanding a unique + * completion, so don't update the "last" buffer because it'll be wrong. + */ + class JLineCompleterClass extends Instance with Completer { + // For recording the buffer on the last tab hit + private var lastBuf: String = "" + private var lastCursor: Int = -1 + + // Does this represent two consecutive tabs? + def isConsecutiveTabs(buf: String, cursor: Int) = + cursor == lastCursor && buf == lastBuf + + // Longest common prefix + def commonPrefix(xs: List[String]) = + if (xs.isEmpty) "" + else xs.reduceLeft(_ zip _ takeWhile (x => x._1 == x._2) map (_._1) mkString) + + // This is jline's entry point for completion. + override def complete(_buf: String, cursor: Int, candidates: JList[CharSequence]): Int = { + val buf = if (_buf == null) "" else _buf + verbosity = if (isConsecutiveTabs(buf, cursor)) verbosity + 1 else 0 + DBG("\ncomplete(%s, %d) last = (%s, %d), verbosity: %s".format(buf, cursor, lastBuf, lastCursor, verbosity)) + + // we don't try lower priority completions unless higher ones return no results. + def tryCompletion(p: Parsed, completionFunction: Parsed => List[String]): Option[Int] = { + completionFunction(p) match { + case Nil => None + case xs => + // modify in place and return the position + xs foreach (candidates add _) + + // update the last buffer unless this is an alternatives list + if (xs contains "") Some(p.cursor) + else { + val advance = commonPrefix(xs) + lastCursor = p.position + advance.length + lastBuf = (buf take p.position) + advance + + DBG("tryCompletion(%s, _) lastBuf = %s, lastCursor = %s, p.position = %s".format(p, lastBuf, lastCursor, p.position)) + Some(p.position) + } + } + } + + def mkDotted = Parsed.dotted(buf, cursor) withVerbosity verbosity + def mkUndelimited = Parsed.undelimited(buf, cursor) withVerbosity verbosity + + // a single dot is special cased to completion on the previous result + def lastResultCompletion = + if (!looksLikeInvocation(buf)) None + else tryCompletion(Parsed.dotted(buf drop 1, cursor), lastResultFor) + + def regularCompletion = tryCompletion(mkDotted, topLevelFor) + def fileCompletion = + if (!looksLikePath(buf)) None + else tryCompletion(mkUndelimited, FileCompletion completionsFor _.buffer) + + /** This is the kickoff point for all manner of theoretically possible compiler + * unhappiness - fault may be here or elsewhere, but we don't want to crash the + * repl regardless. Hopefully catching Exception is enough, but because the + * compiler still throws some Errors it may not be. + */ + try { + (lastResultCompletion orElse regularCompletion orElse fileCompletion) getOrElse cursor + } + catch { + case ex: Exception => + DBG("Error: complete(%s, %s, _) provoked %s".format(_buf, cursor, ex)) + candidates add " " + candidates add "<completion error>" + cursor + } + } + } +} |