What about tuple accessor function for (,,) ... - ?

Marc Weber marco-oweber at gmx.de
Wed Apr 25 11:09:19 EDT 2007

Hi Neil.

> The Yhc compiler uses 8 element tuples in some places - its not a good
> solution ever.
Using them I would be counting commas all the time ;)

> I suspect the use of the 2 element tuple is really common, the 3
> element tuple sees a few outings, and the 4 and above element tuple is
> a bit of a rarity.

Thanks for your answer.
This 4 tuple design can be found in regex-base (Text.Regex.Base.Context)
(before, match, after, [submatch])

I only did need the submatches.
tuple -> hlist -> get 3 element would be an option too ;)

But you are right. It would be mutch better to use

(BMAS = Before Match After Submatches)
data BMASContext = BMASContext { before:: , match:: , after::,
  submatches :: .. }

Then I could do submatches ( "..." =~ "..." ) which would be a lot more
readable, too.

You can define your own.
I have to dive into the regex code much deeper..
It should have been a quick hack :)


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