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Compiler for the Scala Programming Language
/* NSC -- new Scala compiler
* Copyright 2005-2013 LAMP/EPFL
* @author Paul Phillips
*/
package scala.tools.nsc
package interpreter
import scala.reflect.NameTransformer
/** An interface for objects which are aware of tab completion and
* will supply their own candidates and resolve their own paths.
*/
trait CompletionAware {
/** The complete list of unqualified Strings to which this
* object will complete.
*/
def completions(verbosity: Int): List[String]
/** The next completor in the chain.
*/
def follow(id: String): Option[CompletionAware] = None
/** A list of useful information regarding a specific uniquely
* identified completion. This is specifically written for the
* following situation, but should be useful elsewhere too:
*
* x.y.z.methodName
*
* If "methodName" is among z's completions, and verbosity > 0
* indicating tab has been pressed twice consecutively, then we
* call alternativesFor and show a list of overloaded method
* signatures.
*/
def alternativesFor(id: String): List[String] = Nil
/** Given string 'buf', return a list of all the strings
* to which it can complete. This may involve delegating
* to other CompletionAware objects.
*/
def completionsFor(parsed: Parsed): List[String] = {
import parsed.{ buffer, verbosity }
val comps = completions(verbosity) filter (_ startsWith buffer)
val exact = comps contains buffer
val results =
if (parsed.isEmpty) comps
else if (parsed.isUnqualified && !parsed.isLastDelimiter)
if (verbosity > 0 && exact) alternativesFor(buffer)
else comps
else follow(parsed.bufferHead) map (_ completionsFor parsed.bufferTail) getOrElse Nil
results.sorted
}
}
object CompletionAware {
val Empty = new CompletionAware { def completions(verbosity: Int) = Nil }
def unapply(that: Any): Option[CompletionAware] = that match {
case x: CompletionAware => Some((x))
case _ => None
}
/** Create a CompletionAware object from the given functions.
* The first should generate the list of completions whenever queried,
* and the second should return Some(CompletionAware) object if
* subcompletions are possible.
*/
def apply(terms: () => List[String], followFunction: String => Option[CompletionAware]): CompletionAware =
new CompletionAware {
def completions = terms()
def completions(verbosity: Int) = completions
override def follow(id: String) = followFunction(id)
}
/** Convenience factories.
*/
def apply(terms: () => List[String]): CompletionAware = apply(terms, _ => None)
def apply(map: scala.collection.Map[String, CompletionAware]): CompletionAware =
apply(() => map.keys.toList, map.get _)
}