ReplAPI

History of commands that have been entered into the shell, including previous sessions

Shows all imports added that bring values into scope for the commands a user runs; includes imports from the built-in predef and user predef files

Current height of the terminal

Display help text if you don't know how to use the REPL

History of commands that have been entered into the shell during the current session

Shows the imports added to scope by the commands a user has entered so far; excludes imports from the built-in predef and user predef files

The last exception that was thrown in the REPL; null if nothing has yet been thrown. Useful if you want additional information from the thrown exception than the printed stack trace (e.g. many exceptions have additional metadata attached) or if you want to show the stack trace on an exception that doesn't normally print it (e.g. seeing the stack when a Ctrl-C interrupt happened) via lastException.printStackTrace.

Throw away the current scala.tools.nsc.Global and get a new one

Functions that can be used to manipulate the current REPL session: check-pointing progress, reverting to earlier checkpoints, or deleting checkpoints by name.

Frames get pushed on a stack; by default, a saved frame is accessible simply by calling load. If you provide a name when saveing a checkpoint, it can later be loaded directly by providing the same name to load

Un-named checkpoints are garbage collected, together with their classloader and associated data, when they are no longer accessible due to restore. Named checkpoints are kept forever; call delete on them if you really want them to go away.

Lets you configure the pretty-printing of a value. By default, it simply disables truncation and prints the entire thing, but you can set other parameters as well if you want.

If class wrapping is enabled, this lists the names of the previous commands that the current commands actually references (as told by the scalac).

E.g. in a session like

@ val n = 2
n: Int = 2

@ val p = 1
p: Int = 1

@ n + p
res2: Int = 3

this would have returned an empty list if called from the same line as val n = 2 or val p = 1. This would have returned Seq("cmd0", "cmd1") if called from the same line as n + p, as both cmd0, that defines n, and cmd1, that defines p, are referenced from this line.

Current width of the terminal

The front-end REPL used to take user input. Modifiable!

Read/writable prompt for the shell. Use this to change the REPL prompt at any time!

Controls how things are pretty-printed in the REPL. Feel free to shadow this with your own definition to change how things look