Well, my tcLocalBinds seems to have a different type then yours (this is from
my copy of 7.6.3 and it's the same in the HEAD that I just synced):
tcLocalBinds :: HsLocalBinds Name - TcM thing - TcM (HsLocalBinds TcId, thing)
If I want to get a GblEnv out, I can use getGblEnv, but doing this:
mkId :: Maybe FreeVars - LHsExpr Name - Name - TcM Id
mkId fvs expr@(L l _) nm = do
((binds', gbl_env),lie) - captureConstraints $ tcLocalBinds binds getGblEnv
setGblEnv gbl_env (tcLookupId nm)
where
binds= HsValBinds $ ValBindsOut [(NonRecursive, unitBag fixbnd)] []
the_bind = mkTopFunBind (L l nm) [mkMatch [] expr emptyLocalBinds]
fixbnd = L l $ maybe the_bind (\vs - the_bind { bind_fvs = vs }) fvs
fails on the tcLookupId with a GHC internal error complaining that my name is
not in scope during type checking, but it passed the renamer.
Ph.
From: Simon Peyton-Jones [mailto:simo...@microsoft.com]
Sent: dinsdag 10 september 2013 14:19
To: Holzenspies, P.K.F. (EWI)
Cc: glasgow-haskell-users@haskell.org
Subject: RE: Question about correct GHC-API use for type checking (or zonking,
or tidying)
What goes wrong if you follow my suggestion below?
tcLocalBinds takes a set of bindings, such as x=e
and returns a GblEnv whose type envt is extended with a binding for x with its
generalised type.
This type wil indeed be closed, unless the current environment (in which
tcLocalBinds runs) has bindings with open types. Which in your case it probably
doesn't.
I feel that I am not being helpful but I'm not sure how to help more.
S
From: Philip K.F. Hölzenspies [mailto:p.k.f.holzensp...@utwente.nl]
Sent: 04 September 2013 21:25
To: Simon Peyton-Jones
Cc: glasgow-haskell-users@haskell.orgmailto:glasgow-haskell-users@haskell.org
Subject: Re: Question about correct GHC-API use for type checking (or zonking,
or tidying)
Ah, this is good to know. What I really would like is a function:
mkId :: Name - LHsExpr Name - TcM Id
where that Id is something I can store in my own monad (IA). The meaning of
this, is indeed let name = expression as a top-level binding. The
behaviour should actually be the same as that statement at the ghci-prompt. My
IA monad implements liftTcM as something that invokes a TcM-monad, i.e.
liftTcM :: TcM b - IA b
liftTcM thing_inside = do
hsc_env - getSession
stored_ids - getStoredIds :: IA [Id]-- this is the list of all Ids
made through mkId mentioned above
ioMsgMaybe . initTcPrintErrors hsc_env iNTERACTIVE $
setInteractiveContext hsc_env (hsc_IC hsc_env) $
tcExtendGlobalValEnv stored_ids $ -- or tcExtendIdEnv??
thing_inside
In the example you give below, I'm curious which thing_inside you give to
tcLocalBinds to get you the correct global environment. Also, if I do what you
suggest, i.e.
poly_id - setGblEnv gbl_env (tcLookupId the_id_name)
is that poly_id self contained, in the sense that I can put it in a new
instantiation as shown above?
Regards,
Philip
[cid:image001.jpg@01CEAEDB.407DA510]
Simon Peyton-Jonesmailto:simo...@microsoft.com
September 4, 2013 6:00 PM
The id you are getting is a monomorphic id, with a type like a-a, not the
polymorphic forall a. a-a. You don't want to go round arbitrarily creating a
new Id with the same unique but a different type. I have no idea what would
happen then.
It's hard for me to understand just what you code is trying to do. I think you
are making bindig
it = some expr
and then you want the type of it. Maybe something like
(binds', gbl_env) - tcLocalBinds (..your bindin..)
poly_id - setGblEnv gbl_env (tcLooupId the_id_name)
But I'm not totally sure.
S
inline: image001.jpg___
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