[Template-haskell] Re: template-haskell names in 6.3

[Keean Schupke]

So does this work?

    nameModule (mkName "Foo.Bar")

Keean.

Simon Peyton-Jones wrote:

>| As to exactly what I am trying to do, it is to take a string say
>"Test"
>| and prefix
>| it with qCurrentModule to give the global name, so that:
>
>So you can just say
>
>	do { m <- qCurrentModule
>	    ; return (mkName (m ++ ".Test")) }
>
>Let's leave at that for now, if that does what you need.  I'm very
>cautious about adding equalities on Names.  You can always ask if
>	m <- qCurrentModule
>	if (m == nameModule ''Test) ...
>
>Simon
>
>
>| module Main
>|     data X
>| 
>|     main = do
>|        m <- qCurrentModule
>|        if mkQualName m "X" == ''X -- IE I want to test if m.X is
>really
>| the same X as ''X
>|           then putStrLn "Okay"
>|           else putStrLn "Fail"
>| 
>| 
>| 
>|     Keean.
>| 
>| Simon Peyton-Jones wrote:
>| 
>| >Because they the two can behave differently in different contexts.
>It's
>| >like saying why doesn't 1==2 because in the context (\x. x>10) both
>give
>| >False!
>| >
>| >I feel I am missing the point you are trying to make.  I thought I
>had
>| >it when I suggested mkQualName, and you said "that's exactly what I
>| >want".  But you can define mkQualName easily:
>| >	mkQualName m s = mkName (m ++ "." ++ s).
>| >
>| >Why don't you give a complete (but small) example of what you are
>trying
>| >to do?
>| >
>| >Simon
>| >
>| >| -----Original Message-----
>| >| From: Keean Schupke [mailto:k.schupke at imperial.ac.uk]
>| >| Sent: 21 December 2004 10:48
>| >| To: Simon Peyton-Jones
>| >| Cc: template-haskell at haskell.org
>| >| Subject: Re: [Template-haskell] Re: template-haskell names in 6.3
>| >|
>| >| Okay but:
>| >|
>| >|  >module Foo where
>| >|  >   data Test
>| >|  >
>| >|  >module Bar
>| >|  >    import Foo
>| >|  >
>| >|  >    test = (''Test == mkName "Foo.Test")
>| >|
>| >| Test (in this scope) is Foo.Test, so why shouldn't it equal
>| >| mkName "Foo.Test" ?
>| >|
>| >|     Keean.
>| >|
>| >|
>| >| Simon Peyton-Jones wrote:
>| >|
>| >| >No, certainly not.
>| >| >
>| >| >  ''Test :: Name
>| >| >	is a lexically-scoped Name, indissolubly connected to whatever
>| >| >Test means
>| >| >		in the original lexical scope it appeared in
>| >| >
>| >| >  mkName "Foo.Test" :: Name
>| >| >	is a dynamically-scoped Name, captured by whatever context it's
>| >| >spliced into.
>| >| >
>| >| >They aren't the same, and shouldn't be!
>| >| >
>| >| >Simon
>| >| >
>| >| >| -----Original Message-----
>| >| >| From: template-haskell-bounces at haskell.org
>| >| >[mailto:template-haskell-bounces at haskell.org] On
>| >| >| Behalf Of Keean Schupke
>| >| >| Sent: 21 December 2004 10:06
>| >| >| To: Simon Peyton-Jones
>| >| >| Cc: template-haskell at haskell.org
>| >| >| Subject: Re: [Template-haskell] Re: template-haskell names in
>6.3
>| >| >|
>| >| >| I think I am already using that... I wasn't sure if the
>| >'module-part'
>| >| >of the
>| >| >| name was the same as in a global name generated from ''... is:
>| >| >|
>| >| >| module Foo
>| >| >| data Test
>| >| >|
>| >| >| mkName "Foo.Test" == ''Test -- is this true?
>| >| >|
>| >| >|     Keean
>| >| >|
>| >| >| Simon Peyton-Jones wrote:
>| >| >|
>| >| >| >Keean
>| >| >| >
>| >| >| >I was half way through implementing this when I realised it's
>| >there
>| >| >| >already. If you say
>| >| >| >
>| >| >| >	mkName "Foo.baz"
>| >| >| >
>| >| >| >you'll get a dynamically scoped qualified name, just as you
>want.
>| >| >| >
>| >| >| >Is that OK?
>| >| >| >
>| >| >| >Simon
>| >| >| >
>| >| >| >| -----Original Message-----
>| >| >| >| From: template-haskell-bounces at haskell.org
>| >| >| >[mailto:template-haskell-bounces at haskell.org] On
>| >| >| >| Behalf Of Keean Schupke
>| >| >| >| Sent: 03 December 2004 14:38
>| >| >| >| To: Simon Peyton-Jones
>| >| >| >| Cc: template-haskell at haskell.org
>| >| >| >| Subject: Re: [Template-haskell] Re: template-haskell names in
>| >6.3
>| >| >| >|
>| >| >| >| Simon Peyton-Jones wrote:
>| >| >| >|
>| >| >| >| >do you mean
>| >| >| >| >	n <- newName s
>| >| >| >| >or
>| >| >| >| >	let n = mkName s
>| >| >| >| >?
>| >| >| >| >
>| >| >| >| >
>| >| >| >| I mean the latter... or perhaps: "n <- return $ mkName s"...
>| >| >| >|
>| >| >| >| >If the latter, you will get
>| >| >| >| >	data Foo = Foo Foo
>| >| >| >| >
>| >| >| >| >... and then I see what you want.  You want a version of
>mkName
>| >| >that
>| >| >| >is
>| >| >| >| >like giving a qualified name in Haskell.  It's dynamically
>| >scoped
>| >| >| >just
>| >| >| >| >like mkName, but it obeys the usual rules for qualified
>names
>| >in
>| >| >| >| >Haskell.
>| >| >| >| >
>| >| >| >| >To be totally explicit, suppose I have
>| >| >| >| >
>| >| >| >| >	foo = [| mkQualName "Foo" "baz" |]
>| >| >| >| >
>| >| >| >| >then if I call foo thus
>| >| >| >| >
>| >| >| >| >	wibble = \baz -> $foo
>| >| >| >| >
>| >| >| >| >the $foo splice will expand to "Foo.baz", and that won't see
>| >the
>| >| >| >\baz;
>| >| >| >| >it'll see whatever Foo.baz is in scope.
>| >| >| >| >
>| >| >| >| >
>| >| >| >| This is exactly what I am after...
>| >| >| >|
>| >| >| >| >Is that what you seek?  I can see it's reasonable.  I'd need
>to
>| >| >add
>| >| >| >| >
>| >| >| >| >	mkQualName :: String -> String -> Name
>| >| >| >| >
>| >| >| >| >That'd mean an extra form of Name.  Currently, if you say
>| >| >| >| >	'Foo.baz
>| >| >| >| >you'll get a Name whose nameModule isn't necessarily Foo...
>| >it'll
>| >| >be
>| >| >| >the
>| >| >| >| >module that baz was actually defined in.
>| >| >| >| >
>| >| >| >| >
>| >| >| >| I'll leave that up to you, I don't mind if this translation
>| >| >happens,
>| >| >| >as
>| >| >| >| long as it refers to the Foo.baz in dynamic scope the actuall
>| >name
>| >| >| >| can change.
>| >| >| >|
>| >| >| >|     Keean
>| >| >| >| _______________________________________________
>| >| >| >| template-haskell mailing list
>| >| >| >| template-haskell at haskell.org
>| >| >| >| http://www.haskell.org/mailman/listinfo/template-haskell
>| >| >| >
>| >| >| >
>| >| >|
>| >| >| _______________________________________________
>| >| >| template-haskell mailing list
>| >| >| template-haskell at haskell.org
>| >| >| http://www.haskell.org/mailman/listinfo/template-haskell
>| >| >
>| >| >
>| >
>| >
>| >
>| 
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