Re: [Haskell-cafe] ghc -e
On Wed, 6 Jan 2010, Gwern Branwen wrote: On Wed, Jan 6, 2010 at 7:23 PM, Tony Morris wrote: ghc -e "import Control.Monad; forM [[1,2,3]] reverse" As of 6.10.2, the bug whereby the GHC API lets you use functions from anywhere just by naming them (Java-style) has not been fixed: $ ghc -e "Control.Monad.forM [[1,2,3]] reverse" package flags have changed, resetting and loading new packages... Why is this a bug? This is the intended behaviour in GHCi and you can include and exclude packages with -package and -hide-package options, respectively. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc -e
On Wed, Jan 6, 2010 at 6:15 PM, Reid Barton wrote: > On Thu, Jan 07, 2010 at 10:23:35AM +1000, Tony Morris wrote: > > Can I import a module when using ghc -e? > > > > e.g. ghc -e "import Control.Monad; forM [[1,2,3]] reverse" > > One option is to create a file "imports.hs" which contains the text > "import Control.Monad", and then run > > ghc -e "forM [[1,2,3]] reverse" imports.hs > > I use this method in a short shell script "interact" so that I can > apply Haskell functions to files from the command line and don't have > to type the full qualified names of things in modules I use frequently. > Did you know you can put commands in $HOME/.ghci that will be loaded every time you run ghci? So, if you have modules that you commonly use put something like: :m + Control.Monad In your $HOME/.ghci file and then you can use ghci instead of this ghc -e trick. HTH, Jason ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc -e
On Wed, Jan 6, 2010 at 7:35 PM, Tony Morris wrote: > Gwern Branwen wrote: >> On Wed, Jan 6, 2010 at 7:23 PM, Tony Morris wrote: >> >>> ghc -e "import Control.Monad; forM [[1,2,3]] reverse" >>> >> >> As of 6.10.2, the bug whereby the GHC API lets you use functions from >> anywhere just by naming them (Java-style) has not been fixed: >> >> $ ghc -e "Control.Monad.forM [[1,2,3]] reverse" >> package flags have changed, resetting and loading new packages... >> >> :1:25: >> Warning: Defaulting the following constraint(s) to type `Integer' >> `Num t' arising from the literal `3' at :1:25 >> In the expression: 3 >> In the expression: [1, 2, 3] >> In the first argument of `forM', namely `[[1, 2, 3]]' >> >> :1:25: >> Warning: Defaulting the following constraint(s) to type `Integer' >> `Num t' arising from the literal `3' at :1:25 >> In the expression: 3 >> In the expression: [1, 2, 3] >> In the first argument of `forM', namely `[[1, 2, 3]]' >> [[3],[2],[1]] >> it :: [[Integer]] >> (0.01 secs, 1710984 bytes) >> >> > I see the same on GHC 6.10.4. > $ ghc -e "Control.Monad.forM [[1,2,3]] reverse" > [[3],[2],[1]] > > > What would it be fixed to? What is wrong with how it is? Presumably one then have to use some sort of flag to ask for Control.Monad specifically to be visible. What's wrong with it is that this is not merely GHCi behavior, this is universal GHC API behavior and wildly insecure: http://hackage.haskell.org/trac/ghc/ticket/2452 -- gwern ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc -e
On Thu, Jan 07, 2010 at 10:23:35AM +1000, Tony Morris wrote: > Can I import a module when using ghc -e? > > e.g. ghc -e "import Control.Monad; forM [[1,2,3]] reverse" One option is to create a file "imports.hs" which contains the text "import Control.Monad", and then run ghc -e "forM [[1,2,3]] reverse" imports.hs I use this method in a short shell script "interact" so that I can apply Haskell functions to files from the command line and don't have to type the full qualified names of things in modules I use frequently. Regards, Reid Barton ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc -e
Gwern Branwen wrote: > On Wed, Jan 6, 2010 at 7:23 PM, Tony Morris wrote: > >> ghc -e "import Control.Monad; forM [[1,2,3]] reverse" >> > > As of 6.10.2, the bug whereby the GHC API lets you use functions from > anywhere just by naming them (Java-style) has not been fixed: > > $ ghc -e "Control.Monad.forM [[1,2,3]] reverse" > package flags have changed, resetting and loading new packages... > > :1:25: > Warning: Defaulting the following constraint(s) to type `Integer' > `Num t' arising from the literal `3' at :1:25 > In the expression: 3 > In the expression: [1, 2, 3] > In the first argument of `forM', namely `[[1, 2, 3]]' > > :1:25: > Warning: Defaulting the following constraint(s) to type `Integer' > `Num t' arising from the literal `3' at :1:25 > In the expression: 3 > In the expression: [1, 2, 3] > In the first argument of `forM', namely `[[1, 2, 3]]' > [[3],[2],[1]] > it :: [[Integer]] > (0.01 secs, 1710984 bytes) > > I see the same on GHC 6.10.4. $ ghc -e "Control.Monad.forM [[1,2,3]] reverse" [[3],[2],[1]] What would it be fixed to? What is wrong with how it is? -- Tony Morris http://tmorris.net/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc -e
On Wed, Jan 6, 2010 at 7:23 PM, Tony Morris wrote: > ghc -e "import Control.Monad; forM [[1,2,3]] reverse" As of 6.10.2, the bug whereby the GHC API lets you use functions from anywhere just by naming them (Java-style) has not been fixed: $ ghc -e "Control.Monad.forM [[1,2,3]] reverse" package flags have changed, resetting and loading new packages... :1:25: Warning: Defaulting the following constraint(s) to type `Integer' `Num t' arising from the literal `3' at :1:25 In the expression: 3 In the expression: [1, 2, 3] In the first argument of `forM', namely `[[1, 2, 3]]' :1:25: Warning: Defaulting the following constraint(s) to type `Integer' `Num t' arising from the literal `3' at :1:25 In the expression: 3 In the expression: [1, 2, 3] In the first argument of `forM', namely `[[1, 2, 3]]' [[3],[2],[1]] it :: [[Integer]] (0.01 secs, 1710984 bytes) -- gwern ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ghc -e
Can I import a module when using ghc -e? e.g. ghc -e "import Control.Monad; forM [[1,2,3]] reverse" -- Tony Morris http://tmorris.net/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc -e with standard input
interact :: (String -> String) -> IO () is a very handy function for ghc -e, e.g. ghc -e 'interact $ lines . map (show . (*2) . read) . unlines' will multiply the number on every line by 2. (interact takes a function which maps from entire input to entire output) On 05/11/2007, Graham Fawcett <[EMAIL PROTECTED]> wrote: > On Nov 5, 2007 1:46 PM, Maurício <[EMAIL PROTECTED]> wrote: > > Hi, > > > > Is there a way to run 'ghc -e' taking input > > from standard input? I would like to use it > > in a pipe. > > It seems to me that you can use getContents, et. al., as you would > from any other Haskell program: > > $ echo hello there mauricio | ghc -e "print =<< (Control.Monad.liftM > (reverse . words)) getContents" > ["mauricio","there","hello"] > > G > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc -e with standard input
On Nov 5, 2007 2:41 PM, Graham Fawcett <[EMAIL PROTECTED]> wrote: > On Nov 5, 2007 1:46 PM, Maurício <[EMAIL PROTECTED]> wrote: > > Hi, > > > > Is there a way to run 'ghc -e' taking input > > from standard input? I would like to use it > > in a pipe. > > It seems to me that you can use getContents, et. al., as you would > from any other Haskell program: > > $ echo hello there mauricio | ghc -e "print =<< (Control.Monad.liftM > (reverse . words)) getContents" > ["mauricio","there","hello"] > hm, which raises the question of exactly what Maurício meant. Maurício, if you mean you want to do ghc -e "some code which gets its data from standard input", then Graham's solution is exactly what you want. If you mean you want to have ghc -e run some code which itself comes from standard input, then you want xargs (just do a man xargs to see how to use it). In retrospect I'm guessing that Graham answered your real question...? =) -Brent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc -e with standard input
On Nov 5, 2007 1:46 PM, Maurício <[EMAIL PROTECTED]> wrote: > Hi, > > Is there a way to run 'ghc -e' taking input > from standard input? I would like to use it > in a pipe. It seems to me that you can use getContents, et. al., as you would from any other Haskell program: $ echo hello there mauricio | ghc -e "print =<< (Control.Monad.liftM (reverse . words)) getContents" ["mauricio","there","hello"] G ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc -e with standard input
On Nov 5, 2007 1:46 PM, Maurício <[EMAIL PROTECTED]> wrote: > Hi, > > Is there a way to run 'ghc -e' taking input > from standard input? I would like to use it > in a pipe. > xargs ought to do the trick nicely. -Brent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ghc -e with standard input
Hi, Is there a way to run 'ghc -e' taking input from standard input? I would like to use it in a pipe. Thanks, Maurício ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
