prefix() proposal. Closes broadinstitute/cromwell#375

[mcovarr]

This is an attempt to solve the problem presented here of composing a string from a prefix string and a list of zero or more value strings. There are definitely a lot of ways this problem might be solved and this is a concrete proposal just to get a discussion started. 😄

Pinging @slnovak @vdauwera @knoblett @katevoss @jsotobroad @LeeTL1220 @yfarjoun

[Horneth]

I also like the idea of having an mkString for arrays in general. I find the scala one pretty simple and complete but it doesn't have to be the same.
http://www.scala-lang.org/api/2.10.3/#scala.collection.GenTraversableOnce

And we could still have prefix, suffix sugar method on top.

[cjllanwarne]

Like @Horneth I can see the value of a bumper all-in-one mkString(prefix: String, separator: String, suffix: String, array: Array[String]) which might make this redundant. But this still looks good to me 👍

[cjllanwarne]

This link didn't work for me

[mcovarr]

Whoops, that's because I have a superflous dash. Thank you for reviewing so thoroughly! 😄

[cjllanwarne]

Nice! The extra space at the start is awkward but (shrug)

[mcovarr]

@cjllanwarne a Scala-esque mkString wouldn't make this redundant since mkString only inserts strings between elements of the array, it doesn't prepend the strings to every element of the array. For this particular use case, I want a completely blank string if the array is empty, and -e key1=value if there's one element in the array.

Having said that I'm happy to make mkString, prefix, and suffix functions as @Horneth suggested if we're agreed those would be a good idea.

[cjllanwarne]

@mcovarr good point! I think prefix adds by far the most value. mkString is nice (especially if it means we can retire the ${sep=" " array} syntax although I would prefer a better name. Suffix, meh, but there might be uses for it so why not...

[Horneth]

👍

[cjllanwarne]

👍