Merge branch 'feature/unpack-to' of https://github.com/SkyWriter/stack

Author: snoyberg

ChangeLog.md

@@ -11,6 +11,9 @@ Behavior changes:
 
 Other enhancements:
 
+* `stack unpack` now supports a `--to /target/directory` option to
+  specify where to unpack the package into
+
 Bug fixes:
 * When a package contained sublibraries, stack was always recompiling the
   package. This has been fixed now, no recompilation is being done because of

doc/GUIDE.md

@@ -517,6 +517,13 @@ Unpacked yackage-0.8.0 to /var/home/harendra/yackage-0.8.0/
 cueball:~$ cd yackage-0.8.0/
 ```
 
+Note that you can also unpack to the directory of your liking instead of
+the current one by issueing:
+
+```
+cueball:~$ stack unpack yackage-0.8.0 --to ~/work
+```
+
 ### stack init
 This new directory does not have a `stack.yaml` file, so we need to make one
 first. We could do it by hand, but let's be lazy instead with the `stack init`
@@ -1715,7 +1722,8 @@ users. Here's a quick rundown:
   upstream packages available).
 * `stack unpack` is a command we've already used quite a bit for examples, but
   most users won't use it regularly. It does what you'd expect: downloads a
-  tarball and unpacks it.
+  tarball and unpacks it. It accept optional `--to` argument to specify
+  the destination directory.
 * `stack sdist` generates an uploading tarball containing your package code
 * `stack upload` uploads an sdist to Hackage. As of
   version [1.1.0](https://docs.haskellstack.org/en/v1.1.0/ChangeLog/) stack

src/main/Main.hs

@@ -305,7 +305,9 @@ commandLineHandler currentDir progName isInterpreter = complicatedOptions
         addCommand' "unpack"
                     "Unpack one or more packages locally"
                     unpackCmd
-                    (some $ strArgument $ metavar "PACKAGE")
+                    ((,) <$> some (strArgument $ metavar "PACKAGE")
+                         <*> optional (textOption $ long "to" <>
+                                         help "Optional path to unpack the package into"))
         addCommand' "update"
                     "Update the package index"
                     updateCmd
@@ -650,10 +652,11 @@ uninstallCmd _ go = withConfigAndLock go $
       ]
 
 -- | Unpack packages to the filesystem
-unpackCmd :: [String] -> GlobalOpts -> IO ()
-unpackCmd names go = withConfigAndLock go $ do
+unpackCmd :: ([String], Maybe Text) -> GlobalOpts -> IO ()
+unpackCmd (names, Nothing) go = unpackCmd (names, Just ".") go
+unpackCmd (names, Just dstPath) go = withConfigAndLock go $ do
     mSnapshotDef <- mapM (makeConcreteResolver Nothing >=> loadResolver) (globalResolver go)
-    Stack.Fetch.unpackPackages mSnapshotDef "." names
+    Stack.Fetch.unpackPackages mSnapshotDef (T.unpack dstPath) names
 
 -- | Update the package index
 updateCmd :: () -> GlobalOpts -> IO ()