From e06ada8fb7827500ad3cf6b5921a9895c7ea657e Mon Sep 17 00:00:00 2001
From: Mark Harrah <dmharrah@gmail.com>
Date: Tue, 19 Feb 2013 14:33:22 -0500
Subject: [PATCH] Add help for ++ and + commands

---
 main/src/main/scala/sbt/CommandStrings.scala | 28 ++++++++++++++++++++
 main/src/main/scala/sbt/Cross.scala          | 20 ++++++++------
 2 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/main/src/main/scala/sbt/CommandStrings.scala b/main/src/main/scala/sbt/CommandStrings.scala
index 28a057c51..6b1ba99b4 100644
--- a/main/src/main/scala/sbt/CommandStrings.scala
+++ b/main/src/main/scala/sbt/CommandStrings.scala
@@ -241,4 +241,32 @@ load-commands -base ~/.sbt/commands
 		(Path.userHome / sbtrc) ::
 		(s.baseDir / sbtrc asFile) ::
 		Nil
+
+	val CrossCommand = "+"
+	val SwitchCommand = "++"
+
+	def crossHelp: Help = Help.more(CrossCommand, CrossDetailed)
+	def switchHelp: Help = Help.more(SwitchCommand, SwitchDetailed)
+	
+	def CrossDetailed = 
+s"""$CrossCommand <command>
+	Runs <command> for each Scala version specified for cross-building.
+
+	For each string in `crossScalaVersions` in the current project, this command sets the
+	`scalaVersion` of all projects to that version, reloads the build, and
+	executes <command>.  When finished, it reloads the build with the original
+	Scala version.
+
+	See also `help $SwitchCommand`
+"""
+
+	def SwitchDetailed =
+s"""$SwitchCommand <scala-version> [<command>]
+	Changes the Scala version and runs a command.
+
+	Sets the `scalaVersion` of all projects to <scala-version> and reloads the build.
+	If <command> is provided, it is then executed.
+
+	See also `help $CrossCommand`
+"""
 }
diff --git a/main/src/main/scala/sbt/Cross.scala b/main/src/main/scala/sbt/Cross.scala
index 376ee7a05..3499dccf9 100644
--- a/main/src/main/scala/sbt/Cross.scala
+++ b/main/src/main/scala/sbt/Cross.scala
@@ -8,12 +8,16 @@ package sbt
 	import DefaultParsers._
 	import Def.{ScopedKey, Setting}
 	import Scope.GlobalScope
+	import CommandStrings.{CrossCommand,crossHelp,SwitchCommand,switchHelp}
 	import java.io.File
 
 object Cross
 {
-	final val Switch = "++"
-	final val Cross = "+"
+	@deprecated("Moved to CommandStrings.Switch", "0.13.0")
+	final val Switch = CommandStrings.SwitchCommand
+
+	@deprecated("Moved to CommandStrings.Cross", "0.13.0")
+	final val Cross = CommandStrings.CrossCommand
 
 	def switchParser(state: State): Parser[(String, String)] =
 	{
@@ -24,11 +28,11 @@ object Cross
 			val optionalCommand = token(Space ~> matched(state.combinedParser)) ?? ""
 			spacedVersion ~ optionalCommand
 		}
-		token(Switch ~> OptSpace) flatMap { sp => versionAndCommand(!sp.isEmpty) }
+		token(SwitchCommand ~> OptSpace) flatMap { sp => versionAndCommand(!sp.isEmpty) }
 	}
 	def spacedFirst(name: String) = opOrIDSpaced(name) ~ any.+
 
-	lazy val switchVersion = Command.arb(requireSession(switchParser)) { case (state, (version, command)) =>
+	lazy val switchVersion = Command.arb(requireSession(switchParser), switchHelp) { case (state, (version, command)) =>
 		val x = Project.extract(state)
 			import x._
 		val home = IO.resolve(x.currentProject.base, new File(version))
@@ -64,14 +68,14 @@ object Cross
 		}
 
 	def crossParser(state: State): Parser[String] =
-		token(Cross <~ OptSpace) flatMap { _ => token(matched( state.combinedParser & spacedFirst(Cross) )) }
+		token(CrossCommand <~ OptSpace) flatMap { _ => token(matched( state.combinedParser & spacedFirst(CrossCommand) )) }
 
-	lazy val crossBuild = Command.arb(requireSession(crossParser)) { (state, command) =>
+	lazy val crossBuild = Command.arb(requireSession(crossParser), crossHelp) { (state, command) =>
 		val x = Project.extract(state)
 			import x._
 		val versions = crossVersions(state)
-		val current = scalaVersion in currentRef get structure.data map(Switch + " " + _) toList;
-		if(versions.isEmpty) command :: state else versions.map(Switch + " " + _ + " " + command) ::: current ::: state
+		val current = scalaVersion in currentRef get structure.data map(SwitchCommand + " " + _) toList;
+		if(versions.isEmpty) command :: state else versions.map(SwitchCommand + " " + _ + " " + command) ::: current ::: state
 	}
 	def crossVersions(state: State): Seq[String] =
 	{