package scala.tools.nsc
package doc
package base
import comment._
/** This trait extracts all required information for documentation from compilation units.
* The base trait has been extracted to allow getting light-weight documentation
* for a particular symbol in the IDE.*/
trait MemberLookupBase {
val global: Global
import global._
def internalLink(sym: Symbol, site: Symbol): Option[LinkTo]
def chooseLink(links: List[LinkTo]): LinkTo
def toString(link: LinkTo): String
def findExternalLink(sym: Symbol, name: String): Option[LinkToExternal]
def warnNoLink: Boolean
import global._
import rootMirror.{RootPackage, EmptyPackage}
private def isRoot(s: Symbol) = (s eq NoSymbol) || s.isRootSymbol || s.isEmptyPackage || s.isEmptyPackageClass
def makeEntityLink(title: Inline, pos: Position, query: String, site: Symbol) =
new EntityLink(title) { lazy val link = memberLookup(pos, query, site) }
private var showExplanation = true
private def explanation: String =
if (showExplanation) {
showExplanation = false
"""
|Quick crash course on using Scaladoc links
|==========================================
|Disambiguating terms and types: Prefix terms with '$' and types with '!' in case both names are in use:
| - [[scala.collection.immutable.List!.apply class List's apply method]] and
| - [[scala.collection.immutable.List$.apply object List's apply method]]
|Disambiguating overloaded members: If a term is overloaded, you can indicate the first part of its signature followed by *:
| - [[[scala.collection.immutable.List$.fill[A](Int)(⇒A):List[A]* Fill with a single parameter]]]
| - [[[scala.collection.immutable.List$.fill[A](Int,Int)(⇒A):List[List[A]]* Fill with a two parameters]]]
|Notes:
| - you can use any number of matching square brackets to avoid interference with the signature
| - you can use \\. to escape dots in prefixes (don't forget to use * at the end to match the signature!)
| - you can use \\# to escape hashes, otherwise they will be considered as delimiters, like dots.""".stripMargin
} else ""
def memberLookup(pos: Position, query: String, site: Symbol): LinkTo = {
val members = breakMembers(query)
// (1) First look in the root package, as most of the links are qualified
val fromRoot = lookupInRootPackage(pos, members)
// (2) Or recursively go into each containing template.
val fromParents = Stream.iterate(site)(_.owner) takeWhile (!isRoot(_)) map (lookupInTemplate(pos, members, _))
val syms = (fromRoot +: fromParents) find (!_.isEmpty) getOrElse Nil
val links = syms flatMap { case (sym, site) => internalLink(sym, site) } match {
case Nil =>
// (3) Look at external links
syms.flatMap { case (sym, owner) =>
// reconstruct the original link
def linkName(sym: Symbol) = {
def nameString(s: Symbol) = s.nameString + (if ((s.isModule || s.isModuleClass) && !s.isPackage) "$" else "")
val packageSuffix = if (sym.isPackage) ".package" else ""
sym.ownerChain.reverse.filterNot(isRoot(_)).map(nameString(_)).mkString(".") + packageSuffix
}
if (sym.isClass || sym.isModule || sym.isTrait || sym.isPackage)
findExternalLink(sym, linkName(sym))
else if (owner.isClass || owner.isModule || owner.isTrait || owner.isPackage)
findExternalLink(sym, linkName(owner) + "@" + externalSignature(sym))
else
None
}
case links => links
}
links match {
case Nil =>
if (warnNoLink)
reporter.warning(pos, "Could not find any member to link for \"" + query + "\".")
// (4) if we still haven't found anything, create a tooltip
Tooltip(query)
case List(l) => l
case links =>
val chosen = chooseLink(links)
def linkToString(link: LinkTo) = {
val chosenInfo =
if (link == chosen) " [chosen]" else ""
toString(link) + chosenInfo + "\n"
}
if (warnNoLink) {
val allLinks = links.map(linkToString).mkString
reporter.warning(pos,
s"""The link target \"$query\" is ambiguous. Several members fit the target:
|$allLinks
|$explanation""".stripMargin)
}
chosen
}
}
private sealed trait SearchStrategy
private case object BothTypeAndTerm extends SearchStrategy
private case object OnlyType extends SearchStrategy
private case object OnlyTerm extends SearchStrategy
private def lookupInRootPackage(pos: Position, members: List[String]) =
lookupInTemplate(pos, members, EmptyPackage) ::: lookupInTemplate(pos, members, RootPackage)
private def lookupInTemplate(pos: Position, members: List[String], container: Symbol): List[(Symbol, Symbol)] = {
// Maintaining compatibility with previous links is a bit tricky here:
// we have a preference for term names for all terms except for the last, where we prefer a class:
// How to do this:
// - at each step we do a DFS search with the preferred strategy
// - if the search doesn't return any members, we backtrack on the last decision
// * we look for terms with the last member's name
// * we look for types with the same name, all the way up
val result = members match {
case Nil => Nil
case mbrName::Nil =>
var syms = lookupInTemplate(pos, mbrName, container, OnlyType) map ((_, container))
if (syms.isEmpty)
syms = lookupInTemplate(pos, mbrName, container, OnlyTerm) map ((_, container))
syms
case tplName::rest =>
def completeSearch(syms: List[Symbol]) =
syms flatMap (lookupInTemplate(pos, rest, _))
completeSearch(lookupInTemplate(pos, tplName, container, OnlyTerm)) match {
case Nil => completeSearch(lookupInTemplate(pos, tplName, container, OnlyType))
case syms => syms
}
}
//println("lookupInTemplate(" + members + ", " + container + ") => " + result)
result
}
private def lookupInTemplate(pos: Position, member: String, container: Symbol, strategy: SearchStrategy): List[Symbol] = {
val name = member.stripSuffix("$").stripSuffix("!").stripSuffix("*")
def signatureMatch(sym: Symbol): Boolean = externalSignature(sym).startsWith(name)
// We need to cleanup the bogus classes created by the .class file parser. For example, [[scala.Predef]] resolves
// to (bogus) class scala.Predef loaded by the class loader -- which we need to eliminate by looking at the info
// and removing NoType classes
def cleanupBogusClasses(syms: List[Symbol]) = { syms.filter(_.info != NoType) }
def syms(name: Name) = container.info.nonPrivateMember(name.encodedName).alternatives
def termSyms = cleanupBogusClasses(syms(newTermName(name)))
def typeSyms = cleanupBogusClasses(syms(newTypeName(name)))
val result = if (member.endsWith("$"))
termSyms
else if (member.endsWith("!"))
typeSyms
else if (member.endsWith("*"))
cleanupBogusClasses(container.info.nonPrivateDecls) filter signatureMatch
else
strategy match {
case BothTypeAndTerm => termSyms ::: typeSyms
case OnlyType => typeSyms
case OnlyTerm => termSyms
}
//println("lookupInTemplate(" + member + ", " + container + ") => " + result)
result
}
private def breakMembers(query: String): List[String] = {
// Okay, how does this work? Well: you split on . but you don't want to split on \. => thus the ugly regex
// query.split((?<=[^\\\\])\\.).map(_.replaceAll("\\."))
// The same code, just faster:
var members = List[String]()
var index = 0
var last_index = 0
val length = query.length
while (index < length) {
if ((query.charAt(index) == '.' || query.charAt(index) == '#') &&
((index == 0) || (query.charAt(index-1) != '\\'))) {
val member = query.substring(last_index, index).replaceAll("\\\\([#\\.])", "$1")
// we want to allow javadoc-style links [[#member]] -- which requires us to remove empty members from the first
// elemnt in the list
if ((member != "") || (!members.isEmpty))
members ::= member
last_index = index + 1
}
index += 1
}
if (last_index < length)
members ::= query.substring(last_index, length).replaceAll("\\\\\\.", ".")
members.reverse
}
def externalSignature(sym: Symbol) = {
sym.info // force it, otherwise we see lazy types
(sym.nameString + sym.signatureString).replaceAll("\\s", "")
}
}
