Haskell Programming Environment

Keith Wansbrough Keith.Wansbrough@cl.cam.ac.uk
Wed, 25 Oct 2000 17:37:25 +0100


> On Wed, Oct 25, 2000 at 09:03:43AM -0700, Doug Ransom wrote:
> > I would like to be able to inspect the type of things easily by hovering my
> > mouse over an expression.  As a beginner, I find it hard sometimes to get
> > types correct in Haskell since often variables are not declared as a
> > specific type.  
> 
> Since you are typically dealing with incomplete programs in an editor
> this is really tough.  The PSG system was able to generate such
> editors and I once saw it for the purely functional language Sample in
> action:  you could mark any term with the mouse cursor and ask for its
> type. 

One of the emacs modes for Haskell gives the type of the identifier
the cursor is in in the modeline.  It does this by examining the type
signatures in the current file, and having the prelude type signatures
built-in.  This is quite helpful, if incomplete, and fairly easy to
implement.

--KW 8-)


-- 
Keith Wansbrough <kw217@cl.cam.ac.uk>
http://www.cl.cam.ac.uk/users/kw217/
Cambridge University Computer Laboratory.