Scala IDE for Eclipse

This tutorial will show you how to set up the Scala IDE in Eclipse so you can use it to work on the Scala compiler:

• Download and install the latest stable Eclipse release from eclipse.org.
• Install the Scala IDE.
• In Eclipse go to Help -> Install New Software ... In "Work with:", put
• http://download.scala-ide.org/nightly-update-master-trunk (you need the nightly build of the Scala IDE)
• Click Add. Select All. Finish steps to install.

• Tweak the settings for eclipse.ini as discussed here:  https://www.assembla.com/spaces/scala-ide/wiki/Setup 
• Clone the scala git repository:
• git clone git://github.com/scala/scala.git
• cd scala
• cp project.SAMPLE .project
• cp classpath.SAMPLE .classpath
• ./pull-binary-libs.sh # to get the necessary libraries
• Now in Eclipse, import the scala project in your workspace:
• File -> Import ... Existing Projects into Workspace.
• Pick the scala trunk as the source directory.
• Finish.
• Add the reflection part of the scala library (Optional.)
• done in order to shield scala developers from the changes in the reflection part of the compiler and library
• go to Project > Properties
• Java Build Path
• Add Folder and select src/library
• Expand the newly created entry to show Excluded: (None) and double-click on it
• In the inclusion patterns part, click on Add (in the upper part of the window). Include scala/reflect
• In the exclusion patterns part, click on Add (in the lower part of the window). Insert '*'
  
• Finish, Ok
• now the latest reflection part of the library is overriding the ScalaIDE-supplied standard library
  
• Unselect Project -> Build Automatically. (Recommended.)
• If you get any errors, the first thing to do is update the Scala IDE:
• Help > Check for Software Updates
• if you still encounter problems, post a message to the scala-user mailing list.
• Make sure you have the right formatting style (or be ready to see pull requests rejected !). Click on Window->Preferences.
• Go to Java->Code Style->Formatter->Edit. In the General Settings, select Spaces Only for Tab Policy. Select Indentation and tab sizes of 2. 
• Change the profile name and click ok.
• Go to General->Editors->Text Editors. Select the following options:
• Insert spaces for tabs
• Show print margin (120 characters)
• Show line numbers
  
• Show whitespace characters (click on it) and unselect everything but Tab (>>), This is useful to show when tabs have been inserted: you need to replace them with whitespaces.