Tony Garnock-Jones wrote:
Paolo Bonzini wrote:
I'm thinking of adding regex literals to GNU Smalltalk.
I'd be against this.
'a.*b' asRegex
to me seems better, and doesn't require and lexer/parser changes.
It's also slower, which is why as of today 'a.*b' works even without
sending #asRegex.
However, *always* treating string literals as regexes is going to give
problems in the long term. In particular, it would break with another
extension that I was thinking about:
#(1 3 2 6 5 4) select: #odd => #(1 3 5)
#(1 12 2) select: (1 to: 10) => #(1 12)
#('foo' 'bar') select: ##/f./ => #('foo')
This would be quite easily implemented (#select: would send a new
message to its argument, e.g. #~, instead of #value:). If regexes would
be implemented simply as strings, however, there would be a conflict
between the Collection example (second) and the regex example (third):
'foo' select: 'aeiouy' => 'oo'
#('foo') select: 'f.' => cannot make it return 'foo' as I'd like!
That's why in this case, simply using string literals as regexes
wouldn't work. You would need to specify #asRegex to get the desired
behavior.
As I said, I'm also thinking "no"/"not yet". It's not paramount: older
code would be unaffected, and I could start implementing the above
(which is not happening any time soon), and then see if it is a problem.
Just, there *might* be one.
Paolo
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