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<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">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):<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">tcLocalBinds :: HsLocalBinds Name -> TcM thing -> TcM (HsLocalBinds TcId, thing)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">If I want to get a GblEnv out, I can use getGblEnv, but doing this:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">mkId :: Maybe FreeVars -> LHsExpr Name -> Name -> TcM Id<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">mkId fvs expr@(L l _) nm = do<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> ((binds', gbl_env),lie) <- captureConstraints $
<b>tcLocalBinds binds getGblEnv</b><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> setGblEnv gbl_env (tcLookupId nm)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> where<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> binds = HsValBinds $ ValBindsOut [(NonRecursive, unitBag fixbnd)] []<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> the_bind = mkTopFunBind (L l nm) [mkMatch [] expr emptyLocalBinds]<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> fixbnd = L l $ maybe the_bind (\vs -> the_bind { bind_fvs = vs }) fvs<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">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.”<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Ph.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext"> Simon Peyton-Jones [mailto:simonpj@microsoft.com]
<br>
<b>Sent:</b> dinsdag 10 september 2013 14:19<br>
<b>To:</b> Holzenspies, P.K.F. (EWI)<br>
<b>Cc:</b> glasgow-haskell-users@haskell.org<br>
<b>Subject:</b> RE: Question about correct GHC-API use for type checking (or zonking, or tidying)<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US">What goes wrong if you follow my suggestion below?</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US"> </span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US">tcLocalBinds takes a set of bindings, such as x=e</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US">and returns a GblEnv whose type envt is extended with a binding for x with its generalised type.</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US">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.</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US"> </span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US">I feel that I am not being helpful but I’m not sure how to help more.</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US"> </span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US">S</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US"> </span><span lang="EN-GB"><o:p></o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:windowtext">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:windowtext"> "Philip K.F. Hölzenspies"
[<a href="mailto:p.k.f.holzenspies@utwente.nl">mailto:p.k.f.holzenspies@utwente.nl</a>]
<br>
<b>Sent:</b> 04 September 2013 21:25<br>
<b>To:</b> Simon Peyton-Jones<br>
<b>Cc:</b> <a href="mailto:glasgow-haskell-users@haskell.org">glasgow-haskell-users@haskell.org</a><br>
<b>Subject:</b> Re: Question about correct GHC-API use for type checking (or zonking, or tidying)</span><span lang="EN-GB"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-GB"> <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Ah, this is good to know. What I really would like is a function:<br>
<br>
mkId :: Name -> LHsExpr Name -> TcM Id<br>
<br>
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.<br>
<br>
liftTcM :: TcM b -> IA b<br>
liftTcM thing_inside = do<br>
hsc_env <- getSession<br>
stored_ids <- getStoredIds :: IA [Id] -- this is the list of all Ids made through mkId mentioned above<br>
ioMsgMaybe . initTcPrintErrors hsc_env iNTERACTIVE $<br>
setInteractiveContext hsc_env (hsc_IC hsc_env) $<br>
tcExtendGlobalValEnv stored_ids $ -- or tcExtendIdEnv??<br>
thing_inside<br>
<br>
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.<br>
<br>
poly_id <- setGblEnv gbl_env (tcLookupId the_id_name)<br>
<br>
is that poly_id "self contained," in the sense that I can put it in a new instantiation as shown above?<br>
<br>
Regards,<br>
Philip<br>
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<o:p></o:p></span></p>
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<p class="MsoNormal" style="vertical-align:middle"><span lang="EN-GB"><img border="0" width="25" height="25" id="_x0000_i1025" src="cid:image001.jpg@01CEAEDB.407DA510" name="postbox-contact.jpg"><o:p></o:p></span></p>
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<p class="MsoNormal" style="vertical-align:middle"><span lang="EN-GB"><a href="mailto:simonpj@microsoft.com"><b>Simon Peyton-Jones</b></a><o:p></o:p></span></p>
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<p class="MsoNormal" style="vertical-align:middle"><span lang="EN-GB" style="color:#9FA2A5">September 4, 2013 6:00 PM</span><span lang="EN-GB"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US">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.</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US"> </span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US">It’s hard for me to understand just what you code is trying to do. I think you are making bindig</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US"> it = <some expr></span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US"> </span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US">and then you want the type of “it”. Maybe something like</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US"> </span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US"> (binds’, gbl_env) <- tcLocalBinds (..your bindin..)</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US"> poly_id <- setGblEnv gbl_env (tcLooupId the_id_name)</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US"> </span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US">But I’m not totally sure.</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US"> </span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US">S</span><span lang="EN-GB"><o:p></o:p></span></p>
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