[Haskell-cafe] GHCI Feature Request: Last Successful Compilation State Saved

[Christopher Done]

Oh, I didn't reply all. Whoops.

On 28 August 2011 13:40, Christopher Done <chrisdone at googlemail.com> wrote:
> On 27 August 2011 22:59, aditya siram <aditya.siram at gmail.com> wrote:
>> I would like for the GHCI interpreter to save its environment before
>> reloading a file and allowed the user to revert back to that state if the
>> compilation was unsuccessful.
>>
>> Many times I've changed files, loaded them, hit a compilation error and
>> needed, for example, the inferred type signature of some function. Even
>> though that function hasn't been changed I have to either fix my code, undo
>> a bunch of changes or comment out the last change I made and reload in order
>> to do a ":type" on the function. This really breaks the flow of development.
>
> This has been bugging me for a long time and it's been on my TODO list
> for haskell-emacs: https://github.com/chrisdone/haskell-emacs
>
> I just implemented it. http://i.imgur.com/A71T5.png
>
> I just run two ghci processes, one for compiling, one for merely
> loading the code in when the former succeeds.
>
> It's not a very pleasant hack but in conjunction with :set
> -fobject-code it is fast and does not consume that much more memory.
> Considering tibbe's report is 4 years old, I think this solution is
> better than nothing.
>
> Set hs-config-preliminary-load-file to t in hs-config.el and it will
> do a preliminary load in a separate GHCi process.