Error messages from scripts

[Malcolm Sharpe]

Hi, I'm just beginning to learn Scala from the book "Programming in
Scala". My question is whether there is a way to get more concise and
helpful error messages from scripts.

For example, consider the example program helloarg.scala from the
book:
println("Hello, " + args(0) + "!")

If I (incorrectly) run this with "scala helloarg.scala", forgetting
the argument, then I get the following error message:

java.lang.ArrayIndexOutOfBoundsException: 0
at Main$$anon$1.<init>(helloarg.scala:1)
at Main$.main(helloarg.scala:1)
at Main.main(helloarg.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:
39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:
25)
at java.lang.reflect.Method.invoke(Method.java:597)
at scala.tools.nsc.util.ScalaClassLoader$$anonfun$run
$1.apply(ScalaClassLoader.scala:78)
at scala.tools.nsc.util.ScalaClassLoader
$class.asContext(ScalaClassLoader.scala:24)
at scala.tools.nsc.util.ScalaClassLoader
$URLClassLoader.asContext(ScalaClassLoader.scala:88)
at scala.tools.nsc.util.ScalaClassLoader
$class.run(ScalaClassLoader.scala:78)
at scala.tools.nsc.util.ScalaClassLoader
$URLClassLoader.run(ScalaClassLoader.scala:101)
at scala.tools.nsc.ObjectRunner$.run(ObjectRunner.scala:33)
at scala.tools.nsc.ObjectRunner$.runAndCatch(ObjectRunner.scala:40)
at scala.tools.nsc.ScriptRunner.scala$tools$nsc$ScriptRunner$
$runCompiled(ScriptRunner.scala:171)
at scala.tools.nsc.ScriptRunner$$anonfun$runScript
$1.apply(ScriptRunner.scala:188)
at scala.tools.nsc.ScriptRunner$$anonfun$runScript
$1.apply(ScriptRunner.scala:188)
at scala.tools.nsc.ScriptRunner$$anonfun$withCompiledScript$1.apply
$mcZ$sp(ScriptRunner.scala:157)
at scala.tools.nsc.ScriptRunner$$anonfun$withCompiledScript
$1.apply(ScriptRunner.scala:131)
at scala.tools.nsc.ScriptRunner$$anonfun$withCompiledScript
$1.apply(ScriptRunner.scala:131)
at scala.tools.nsc.util.package$.waitingForThreads(package.scala:26)
at scala.tools.nsc.ScriptRunner.withCompiledScript(ScriptRunner.scala:
130)
at scala.tools.nsc.ScriptRunner.runScript(ScriptRunner.scala:188)
at scala.tools.nsc.ScriptRunner.runScriptAndCatch(ScriptRunner.scala:
201)
at scala.tools.nsc.MainGenericRunner.runTarget
$1(MainGenericRunner.scala:58)
at scala.tools.nsc.MainGenericRunner.process(MainGenericRunner.scala:
80)
at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:
89)
at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)

Yikes! Compare with the error message produced from a comparable
Python script:

Traceback (most recent call last):
File "helloarg.py", line 3, in <module>
print 'Hello, ' + sys.argv[1] + '!'
IndexError: list index out of range


Is there something I can do about this to get better error messages?
To clarify, what I like more about the Python error message is:
- The most important information goes at the bottom. When reading
console output, this is helpful.
- The traceback starts in my program, omitting runner cruft that isn't
meaningful or useful to me.
- There's some other helpful information included: the source of the
line where the error occurred, a written description of the error, and
so on.

Thanks!