On Sat, Apr 5, 2014 at 5:21 PM, Robert Vollmert wrote:

- clobbering the environment by prepending to an association list makes me wonder if that's really what happens when the variable is already defined

Yes, that does raise flags. The haskell here: installEnv <- getEnvironment >>= return . (:) ("GOBIN", gOBIN) which I'd probably write as installEnv <- (("GOBIN", gOBIN) :) <$> getEnvironment doesn't match the python here: GOBIN = tempfile.gettempdir() os.environ['GOBIN'] = GOBIN in the sense that the case for a predefined GOBIN in the environment will lead to different results. At least I'll be surprised if otherwise. To Matt: have you tested your haskell version? You might want to take a look at System.Posix.Env.putenv. -- Kim-Ee

I considered the same thing with an existing GOBIN env var. I did actually test it and found it worked as expected. Items earlier in the list seem to have higher priority. I prefer not to use setenv, because I want to exec into the binary later without GOBIN clobbered, which means keeping the current environment pristine. Good point about it not matching the Python version, but then a few other things don't either now. :) Here's the latest version: http://pastebin.com/EejABjpR Something I can't get my head around: On line 50-52, I have a function that returns the result of getting the current directory (curDir) joined with the package path (maybeToList package). Is there someway to get the current directory without having to store the action the way that I am doing? <$> would work if the current directory was the last argument to the joinPath, but here it's the first. Thanks so much for your help. On Sun, Apr 6, 2014 at 2:48 AM, Andrew Gibiansky

wrote:

The script itself looks pretty good to me, but you might want to take a look at Shelly https://hackage.haskell.org/package/shelly [0] for Haskell scripting in the future. It's a really nice library / DSL for "bash"-like scripting directly in Haskell. If you try out Shelly, I suggest trying it with ClassyPrelude and -XOverloadedStrings, which makes dealing with all the Text and FilePath types bearable. (Heh, though it's annoying, having FilePath as a separate type once prevented me from writing code that deleted my home directory upon being run... fun story.)

[0] https://hackage.haskell.org/package/shelly

On Sat, Apr 5, 2014 at 4:33 AM, Kim-Ee Yeoh wrote:

...

On Sat, Apr 5, 2014 at 5:21 PM, Robert Vollmert wrote:

...

- clobbering the environment by prepending to an association list makes me wonder if that’s really what happens when the variable is already defined

Yes, that does raise flags.

The haskell here:

installEnv <- getEnvironment >>= return . (:) ("GOBIN", gOBIN)

which I'd probably write as

installEnv <- (("GOBIN", gOBIN) :) <$> getEnvironment

doesn't match the python here:

GOBIN = tempfile.gettempdir() os.environ['GOBIN'] = GOBIN

in the sense that the case for a predefined GOBIN in the environment will lead to different results. At least I'll be surprised if otherwise.

To Matt: have you tested your haskell version? You might want to take a look at System.Posix.Env.putenv.

-- Kim-Ee

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