regex to remove all whitespaces except between brackets

Question

I\'ve been wrestling with an issue I was hoping to solve with regex.

Let\'s say I have a string that can contain any alphanumeric with the possibility of a substrin

Answer 1

How to do this depends on what should be done with:

a b [ c [ d [ e ] f ] g

That is ambiguous; possible answers are at least:

• ab[ c [ d [ e ] f ]g
• ab[ c [ d [ e ]f]g
• error out; the brackets don't match!

For the first two cases, you can use regexps. For the third case, you'd be much better off with a (small) parser.

For either case one or two, split the string on the first [. Strip spaces from everything before [ (that's obviously outside of the brackets). Next, look for .*\] (case 1) or .*?\] (case 2) and move that over to your output. Repeat until you're out of input.