Can't use GStrings as map keys

This is not really true as stated since:

someString = 'blah'

def someFunction ( a ) {
  println ( a.toString ( ) )
  return a.toString ( )
}

assert someFunction ( datum : 'A String.' ) ==  '{datum=A String.}'
assert someFunction ( ( someString ) : 'A String.' ) == '{blah=A String.}'
assert someFunction ( 'aString' : 'A String.' ) == '{aString=A String.}'
assert someFunction ( "X${someString}" : 'A GString.' ) == '{Xblah=A GString.}'

appears to work fine. This issue arises originally from a problem in Gant, so it seems this may actually be a problem in the treatment of parameters in the target/task closure in gant.Gant rather than a Groovy problem.

As blackdrag pointed out on the mail lists, it is not clear that unevaluated GStrings make sensible map keys – the problem is that the key is variable not constant, so it is not clear that the key can ever be found during lookup.

So although GStrings can appear as map keys, it makes far more sense to say that keys should be constant so instead of using:

"X${someString}"

use

'X' + someString

to enforce evaluation to a constant string.

It is not clear to me how or whether to progress this issue or just declare it to be a non-issue.

Lowering the priority since it is not clear there is actually a problem here to be solved.

I think it would be fine to close this. It is technically a bug, but I don't think it is worth spending the effort on. You may want to add something to the Gant documentation saying that you can't use GStrings for target names. Not sure how often it would come up, but it would be a frustrating sort of issue to try and work out for a user not on the mailing lists and such.

Comment added to http://groovy.codehaus.org/Gant_Tasks