Exiting Scripts

The defaults configuration prevents script from calling System.exit(), because this terminates the entire JVM (so your application will exit).

The preferred alternative is to call abort(), which is part of the Feather runtime. (See class FeatherExtensions)

abort() is just shorthand for throw Abort(). Abort extends Throwable (not Excpetion).

Stopping Scripts externally

When feather is used as a scripting language within an application, you probably need a mechanism to kill the script (especially if the script has a bug, which causes an endless loop).

Here's some Kotlin pseudocode which runs a script, that can be killed later :

val config = FeatherConfiguration().apply {
    // NOTE, the default value is false.
    throwWhenInterrupted = true
}
val results = FeatherCompiler( config ).compile( scripts )

val scriptThread = Thread {
    // Run the script (not shown here)
}

scriptThread.start()

The script can then be killed using :

scriptThread.interrupt()

When the throwWhenInterrupted option is set, every feather loop (for, while and do while) throws an InteruptedException if Thread.isInterrupted() == true.

Note. If the script is in an endless loop within a Java library (i.e. the loop isn't part of a Feather script), then interrupt() may not kill the script.

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