Re: [Haskell-cafe] shadowing keywords like otherwise
Vasili I. Galchin wrote: It seems to me that in the code base somewhere that there is a redefine of the keywordotherwise. I haven't read the Haskell 98 Report but I thought that it was not possible to redefine keywords. ?? otherwise is not a keyword. It is just defined as a normal function like so: otherwise = True Ciao, Janis. -- Dr. Janis Voigtlaender http://wwwtcs.inf.tu-dresden.de/~voigt/ mailto:vo...@tcs.inf.tu-dresden.de ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] shadowing keywords like otherwise
Vasili I. Galchin wrote:
so Janis I have to look where the original author overrode otherwise?
If so, just great .. a ton of code. ;^(
No, you don't have to look for this. It is in the code snippet you sent:
swishParse :: String - String - SwishStateIO (Maybe RDFGraph)
swishParse fnam inp =
do { fmt - gets $ format
; case fmt of
N3- swishParseN3 fnam inp
otherwise -
do { swishError (Unsupported file format: ++(show
fmt)) 4
; return Nothing
}
}
In the case expression you use otherwise as a variable. But you do not
use that variable in that branch. Hence the warning:
Swish/HaskellRDF/SwishCommands.hs:304:12:
Warning: Defined but not used: `otherwise'
This has nothing to do with someone else shadowing the definition of
otherwise.
Ciao,
Janis.
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http://wwwtcs.inf.tu-dresden.de/~voigt/
mailto:vo...@tcs.inf.tu-dresden.de
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Re: [Haskell-cafe] shadowing keywords like otherwise
Hi Vasili,
This isn't really a shadowing/redefinition issue. Here's
a perfectly legitimate snippet that compiles fine:
f 0 = 0
f otherwise = 1+otherwise
Redefinition is when you have:
g = let otherwise = not in x
-- Kim-Ee
VasiliIGalchin wrote:
swishParse :: String - String - SwishStateIO (Maybe RDFGraph)
swishParse fnam inp =
do { fmt - gets $ format
; case fmt of
N3- swishParseN3 fnam inp
otherwise -
do { swishError (Unsupported file format: ++(show fmt))
4
; return Nothing
}
}
I am receiving a shadow warning:
Swish/HaskellRDF/SwishCommands.hs:304:12:
Warning: Defined but not used: `otherwise'
It seems to me that in the code base somewhere that there is a redefine
of
the keywordotherwise. I haven't read the Haskell 98 Report but I thought
that it was not possible to redefine keywords. ??
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Re: [Haskell-cafe] shadowing keywords like otherwise
I meant, of course,
g = let otherwise = not in otherwise
Sorry for the noise.
-- Kim-Ee
Kim-Ee Yeoh wrote:
Hi Vasili,
This isn't really a shadowing/redefinition issue. Here's
a perfectly legitimate snippet that compiles fine:
f 0 = 0
f otherwise = 1+otherwise
Redefinition is when you have:
g = let otherwise = not in x
-- Kim-Ee
VasiliIGalchin wrote:
swishParse :: String - String - SwishStateIO (Maybe RDFGraph)
swishParse fnam inp =
do { fmt - gets $ format
; case fmt of
N3- swishParseN3 fnam inp
otherwise -
do { swishError (Unsupported file format: ++(show
fmt)) 4
; return Nothing
}
}
I am receiving a shadow warning:
Swish/HaskellRDF/SwishCommands.hs:304:12:
Warning: Defined but not used: `otherwise'
It seems to me that in the code base somewhere that there is a redefine
of
the keywordotherwise. I haven't read the Haskell 98 Report but I
thought
that it was not possible to redefine keywords. ??
--
View this message in context:
http://www.nabble.com/%22shadowing%22-keywords-like-%22otherwise%22-tp24239153p24239439.html
Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.
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Re: [Haskell-cafe] shadowing keywords like otherwise
Hello Vasili,
Sunday, June 28, 2009, 10:39:37 AM, you wrote:
; case fmt of
N3 - swishParseN3 fnam inp
otherwise -
do { swishError (Unsupported file format: ++(show fmt)) 4
; return Nothing
}
}
first, otherwise aka True is used in *condition* part of case
statement. here you should use _
second, otherwise isn't a keyword, just a Prelude definition. here,
you assign fmt value to this identifier
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Bulatmailto:bulat.zigans...@gmail.com
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Re: [Haskell-cafe] shadowing keywords like otherwise
On Sun, Jun 28, 2009 at 12:49:12AM -0700, Kim-Ee Yeoh wrote: This isn't really a shadowing/redefinition issue. Here's a perfectly legitimate snippet that compiles fine: f 0 = 0 f otherwise = 1+otherwise What? It is a redefinition issue *as well*, but this kind of warning isn't active by default Prelude :s -Wall Prelude let f 0 = 0; f otherwise = 1 + otherwise interactive:1:15: Warning: This binding for `otherwise' shadows the existing binding imported from Prelude In the definition of `f' -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] shadowing keywords like otherwise
On Jun 28, 2009, at 02:39 , Vasili I. Galchin wrote:
; case fmt of
N3- swishParseN3 fnam inp
otherwise -
do { swishError (Unsupported file format: ++(show
fmt)) 4
; return Nothing
}
}
I am receiving a shadow warning:
Swish/HaskellRDF/SwishCommands.hs:304:12:
Warning: Defined but not used: `otherwise'
1. otherwise isn't a keyword, it's a function (well, CAF).
2. if you use a variable in a case alternative, that variable is
created and bound. I think you wanted to use _ instead of
otherwise there.
--
brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com
system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu
electrical and computer engineering, carnegie mellon universityKF8NH
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Re: [Haskell-cafe] shadowing keywords like otherwise
Whoops, you're right. Interestingly, the shadowing warnings vary between the 2 examples I gave, i.e. shadowing within 'function definition' vs 'binding group'. Felipe Lessa wrote: On Sun, Jun 28, 2009 at 12:49:12AM -0700, Kim-Ee Yeoh wrote: This isn't really a shadowing/redefinition issue. Here's a perfectly legitimate snippet that compiles fine: f 0 = 0 f otherwise = 1+otherwise What? It is a redefinition issue *as well*, but this kind of warning isn't active by default Prelude :s -Wall Prelude let f 0 = 0; f otherwise = 1 + otherwise interactive:1:15: Warning: This binding for `otherwise' shadows the existing binding imported from Prelude In the definition of `f' -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- View this message in context: http://www.nabble.com/%22shadowing%22-keywords-like-%22otherwise%22-tp24239153p24244760.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
