Source Location of DataCon objects in GHC 7.4.1 API

[Simon Peyton-Jones]

That's our policy too, as you will see if you look at any closed Trac ticket.  We have thousands of regression tests, and they are fabulously useful.  But it's a judgement call when the scope is extremely narrow and the regression test is hard to make, and I decided not to.  

By all means submit a regression test for this one; I'll gladly commit it.

S 

| -----Original Message-----
| From: Jacques Carette [mailto:carette at mcmaster.ca]
| Sent: 05 June 2012 13:45
| To: Simon Peyton-Jones
| Cc: JP Moresmau; glasgow-haskell-users at haskell.org
| Subject: Re: Source Location of DataCon objects in GHC 7.4.1 API
| 
| One bit of experience from my Maple days: we made it a policy to create
| regression tests for every single bug we fixed.  No bug could be marked
| closed without an identifier for the test that makes sure this does not
| revert.
| 
| This seemed like too much at first, but over the years, we were always
| glad of this.  We caught all sorts of very strange bugs because of doing
| this.  This is especially valuable for very long-lived software (like
| GHC), where the time-span between the last time the problem showed up
| and when it occurs again can be 15+ years.
| 
| In other words, I am saying that even though in the present context this
| feature/bug can seem small, it is extremely hard to predict what context
| will be true in 10+ years, where this regression may become a symptom of
| something bigger.
| 
| Jacques
| 
| On 05/06/2012 8:36 AM, Simon Peyton-Jones wrote:
| > Done.  I don't think it's worth a regression test.
| >
| > SImon
| >
| > commit cb705a38d677e2ab4cad37447c8180bd397d5576
| > Author: Simon Peyton Jones<simonpj at microsoft.com>
| > Date:   Tue Jun 5 13:35:07 2012 +0100
| >
| >      Add sensible locations to record-selector bindings
| >
| >   compiler/typecheck/TcTyClsDecls.lhs |   26 +++++++++++++------------
| -
| >   1 files changed, 13 insertions(+), 13 deletions(-)
| >
| > | -----Original Message-----
| > | From: glasgow-haskell-users-bounces at haskell.org
| > | [mailto:glasgow-haskell- users-bounces at haskell.org] On Behalf Of
| > | Simon Peyton-Jones
| > | Sent: 05 June 2012 12:38
| > | To: JP Moresmau; glasgow-haskell-users at haskell.org
| > | Subject: RE: Source Location of DataCon objects in GHC 7.4.1 API
| > |
| > | Ah I see.  I'm fixing this.
| > |
| > | Simon
| > |
| > | | -----Original Message-----
| > | | From: glasgow-haskell-users-bounces at haskell.org
| > | | [mailto:glasgow-haskell- users-bounces at haskell.org] On Behalf Of
| > | | JP Moresmau
| > | | Sent: 01 June 2012 10:25
| > | | To: glasgow-haskell-users at haskell.org
| > | | Subject: Source Location of DataCon objects in GHC 7.4.1 API
| > | |
| > | | Hello
| > | |
| > | | I have a failing test in BuildWrapper when moving from GHC 7.0.4
| > | | to 7.4.1. As far I can tell, in the TypecheckedSource I get
| > | | DataCon objects that have no location info, and hence I can't
| > | | retrieve them by location... Which is useful in a IDE (tell me
| > | | what's under my mouse cursor, tell me where else it's used).
| > | |
| > | | Given the simple data declaration:
| > | | data DataT=MkData {name :: String}
| > | |
| > | | In 7.0.4 I obtain a hierarchy that ends in FunBind (on a Var
| > | | called "name")/MatchGroup/Match/ConPatOut and the contained
| > | | DataCon named "MkData" has a SrcSpan associated with it, and so do
| > | | the Var, MatchGroup and Match.
| > | | In 7.4.1 I have the same hierarchy but the DataCon tells me "no
| > | | location info". The Var "name" has a location, but the MatchGroup
| > | | and Match don't either.
| > | |
| > | | Is it a normal change? Do I need to change something in the way I
| > | | load the module? Is it a regression?
| > | |
| > | | Thanks!
| > | |
| > | | --
| > | | JP Moresmau
| > | | http://jpmoresmau.blogspot.com/
| > | |
| > | | _______________________________________________
| > | | Glasgow-haskell-users mailing list
| > | | Glasgow-haskell-users at haskell.org
| > | | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
| > |
| > |
| > |
| > | _______________________________________________
| > | Glasgow-haskell-users mailing list
| > | Glasgow-haskell-users at haskell.org
| > | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
| >
| >
| >
| > _______________________________________________
| > Glasgow-haskell-users mailing list
| > Glasgow-haskell-users at haskell.org
| > http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
|