Evaluate string command in Scala from REPL

read-eval-print-loop, scala

Solution

No REPL hacking necessary—just switch to power user mode, which gives you access to the current `scala.tools.nsc.interpreter.IMain` as `intp`:

scala> :power
** Power User mode enabled - BEEP BOOP SPIZ **
** :phase has been set to 'typer'.          **
** scala.tools.nsc._ has been imported      **
** global._ and definitions._ also imported **
** Try  :help,  vals.<tab>,  power.<tab>    **

scala> intp.interpret("val x = 42")
x: Int = 42
res0: scala.tools.nsc.interpreter.package.IR.Result = Success

scala> x
res1: Int = 42

This works since at least 2.9.1.

Problem

Is there a way to evaluate a arbitrary string from Scala as if the same text was entered into the Scala REPL directly? I mean, I would like to do something like this: ``` scala> eval("val x = 42") scala> x res2: Int = 42 ``` Since the Scala REPL is accepting commands in an eval loop using jline (I believe) and then compiling/interpreting it, there has to be a way to submit an arbitrary line of text. I am willing to hack the Scala REPL if necessary.

Original source