REPL Autoload file

[bholt]

This PR enables users to specify commands that will automatically be executed when the REPL loads (such as including time zone, sources, etc).

So far, I have the repl loading a single file in the user's home directory (~/.scalding_repl).

Is there any value in trying to make it search other places for files, such as walking up to the root from the current directory (as many other configs do). This doesn't seem particularly useful for the way most people run from the root of the project.

[johnynek]

I guess it does sound nice to have it walk up to at least the user home directory so that each project can have its own custom imports. :/

Any way to test this?

[bholt]

Other things that might go in this PR/config:

• Customize prompt (mostly because it'd be awesome to have a colored prompt, but ):

  // In .scalding_repl:
  ScaldingShell.prompt = Console.BLUE + "\nscalding> " + Console.RESET
  
  // in ScaldingILoop:
  override def prompt: String = ScaldingShell.prompt()

[bholt]

Any way to test this?

I think I can add another repl test to the script we already have. I'll give it a try.

[bholt]

Now the REPL will automatically load files named ".scalding_repl" in your path. The prompt can also now be customized (presumably from in a .scalding_repl file, but can be done manually as well).

Ready for anyone who's interested to review this.

[johnynek]

you say current directory here, but you are actually getting the user's home dir.

I like the idea of a current directory so I could put some .scalding_repl file in my science directory have that different from my home. Am I missing this?

[bholt]

Actually, this property is named kind of confusingly named: "user.dir" is the current working directory (of the user, I guess...)

scala> System.getProperty("user.dir")
res0: java.lang.String = /Users/bholt/dev/hub/scalding

scala> System.getProperty("user.home")
res1: java.lang.String = /Users/bholt

[johnynek]

Thanks for clearing me up there! :)

[johnynek]

also, can you add a quick note in the REPL wiki page about how to use this feature?

[bholt]

Roger, Rodger.