[racket] Puzzled about type inference

From: Sam Tobin-Hochstadt (samth at cs.indiana.edu)
Date: Tue Aug 12 13:36:04 EDT 2014

I think that it would work better to:

a. Associate the information with a syntax object rather than a location.
b. Provide an sexp rather than a string, so that it can be formatted
appropriately by DrRacket.

Sam
On Aug 12, 2014 12:15 PM, "Robby Findler" <robby at eecs.northwestern.edu>
wrote:

> That would be great. I think you'd just want to tell check syntax "at
> this position, here is a string to show the user". Is that ok? (And
> you'd put newlines in the string to format it, I guess?)
>
> Robby
>
> On Tue, Aug 12, 2014 at 8:55 AM, Sam Tobin-Hochstadt
> <samth at cs.indiana.edu> wrote:
> > [rather late]
> >
> > Typed Racket knows quite a bit about the types of expressions, not
> > just constants, even when type checking fails. I think we could use a
> > logging mechanism similar to the one that allows check syntax to work
> > even when type checking fails to communicate types of sub-expressions
> > to DrRacket.
> >
> > There are some cases where expressions are typechecked twice that
> > might cause problems, but in general this should be pretty easy.
> >
> > Sam
> >
> > On Tue, Aug 5, 2014 at 9:04 PM, Robby Findler
> > <robby at eecs.northwestern.edu> wrote:
> >> Is TR's type checker organized in such a way that the decisions about
> >> what types are given to constants decided as a separate (first) phase?
> >> That is, no matter the context, is this constant:
> >>
> >>    #(0 0)
> >>
> >> always going to be given the type (Vector Integer Integer), assuming
> >> there is no annotation?
> >>
> >> If so, then it seems like TR could communicate that series of
> >> decisions even when type checking fails and that that might be useful
> >> for this program?
> >>
> >> Robby
> >>
> >>
> >> On Tue, Aug 5, 2014 at 7:53 PM, Matthias Felleisen <
> matthias at ccs.neu.edu> wrote:
> >>>
> >>> You guys came up with some wonderful ideas.
> >>>
> >>> I think this particular one is easy to implement when
> >>> the program type checks. But when it doesn't, what do
> >>> you show?
> >>>
> >>> -- Matthias
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> On Aug 5, 2014, at 6:13 PM, Alexander D. Knauth wrote:
> >>>
> >>>>
> >>>> On Aug 5, 2014, at 6:06 PM, Raoul Duke <raould at gmail.com> wrote:
> >>>>
> >>>>>>>     add type declarations to variables and fields and function and
> method signatures.
> >>>>>>
> >>>>>> A good motto, which I shall endeavour to remember.
> >>>>>
> >>>>> what i do not get about TR and other languages (ocaml, haskell, etc.)
> >>>>> is: there are these rules of thumb that you must somehow learn to
> keep
> >>>>> yourself out of the weeds, but you only get to learn them the long
> and
> >>>>> hard way. why don't the runtimes/ides
> >>>>>
> >>>>> (1) have a switch that says "hey, force me, the user, to put in type
> >>>>> annotations by hand in the critical places, ok? so i don't have to
> >>>>> suffer so much down the road, ok?"
> >>>>>
> >>>>> (2) put the inferred annotations into the code as it goes along so i
> >>>>> can see what kind of crazy talk the inference engine is having with
> >>>>> itself?
> >>>>
> >>>> I’m just wondering, would it be possible for DrRacket to do something
> where you can right-click a variable or expression or something and one of
> the options is to see what the inferred type is?
> >>>>
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