Bug in Parsec.Token

wren ng thornton wren at community.haskell.org
Sat Apr 3 07:21:27 EDT 2010

Isaac Dupree wrote:
> On 04/02/10 02:30, Greg Fitzgerald wrote:
>>> if more packages want
>>> Parsec 2 then it's less disruption to split off parsec 3
>> Luckily, there is very little disruption to split off parsec 2.1
>> because there's no harm in leaving old packages as "parsec<  3".
> I assert that there is harm.  There will be duplicate packages installed 
> (parsec-2.1 and parsec98-2.1) with identical code.  Also, we would be 
> committing to upload any bugfix/maintenance updates to both 'branches'.
> Do you wish to argue that this is an acceptable level of harm? (I would 
> be easily susceptible to such an argument...)

I'd argue that it's acceptable, at least under this plan:

* fork parsec-2.1 as parsec2-2.1
* continue to develop parsec2-* (as desired)
* deprecate parsec<3 with message to switch to parsec2-*
* continue parsec>=3 as parsec-*

The harm is minimal because:

(a) anyone who is too lazy to upgrade their .cabal can still use 
parsec-2.1 until it bitrots

(b) anyone who is too lazy to upgrade their code to parsec>=3 can just 
update their .cabal to use parsec2-* if they want to avoid bitrot

(c) anyone using parsec>=3 won't notice a thing.

Live well,

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