Add completion for stack (haskell project builder)

src/_stack

@@ -0,0 +1,55 @@
+#compdef stack
+
+_stack () {
+    _arguments \
+        --version'[Show version]' \
+        --help'[Show this help text]' \
+        '--docker*''[Run "stack --docker-help" for details]' \
+        --verbosity'[Verbosity: silent, error, warn, info, debug]' \
+        {-v,--verbose}'[Enable verbose mode: verbosity level "debug"]' \
+        --system-ghc'[Enable using the system installed GHC (on the PATH) if available and a matching version]' \
+        --no-system-ghc'[Disable using the system installed GHC (on the PATH) if available and a matching version]' \
+        --install-ghc'[Enable downloading and installing GHC if necessary (can be done manually with stack setup)]' \
+        --no-install-ghc'[Disable downloading and installing GHC if necessary (can be done manually with stack setup)]' \
+        --arch'[System architecture, e.g. i386, x86_64]' \
+        --os'[Operating system, e.g. linux, windows]' \
+        {-j,--jobs}'[Number of concurrent jobs to run]' \
+        --extra-include-dirs'[Extra directories to check for C header files]' \
+        --extra-lib-dirs'[Extra directories to check for libraries]' \
+        --skip-ghc-check'[Enable skipping the GHC version and architecture check]' \
+        --no-skip-ghc-check'[Disable skipping the GHC version and architecture check]' \
+        --skip-msys'[Enable skipping the local MSYS installation (Windows only)]' \
+        --no-skip-msys'[Disable skipping the local MSYS installation (Windows only)]' \
+        --resolver'[Override resolver in project file]' \
+        --no-terminal'[Override terminal detection in the case of running in a false terminal]' \
+        --stack-yaml'[Override project stack.yaml file (overrides any STACK_YAML environment variable)]' \
+        '*: :__stack_modes'
+}
+
+__stack_modes () {
+    _values \
+        'subcommand' \
+        'build[Build the project(s) in this directory/configuration]' \
+        'install[Build executables and install to a user path]' \
+        'test[Build and test the project(s) in this directory/configuration]' \
+        'bench[Build and benchmark the project(s) in this directory/configuration]' \
+        'haddock[Generate haddocks for the project(s) in this directory/configuration]' \
+        'new[Create a brand new project]' \
+        'init[Initialize a stack project based on one or more cabal packages]' \
+        'solver[Use a dependency solver to try and determine missing extra-deps]' \
+        'setup[Get the appropriate ghc for your project]' \
+        'path[Print out handy path information]' \
+        'unpack[Unpack one or more packages locally]' \
+        'update[Update the package index]' \
+        'upgrade[Upgrade to the latest stack (experimental)]' \
+        'upload[Upload a package to Hackage]' \
+        'dot[Visualize your projects dependency graph using Graphviz dot]' \
+        'exec[Execute a command]' \
+        'ghc[Run ghc]' \
+        'ghci[Run ghci in the context of project(s)]' \
+        'ide[Run ide-backend-client with the correct arguments]' \
+        'runghc[Run runghc]' \
+        'clean[Clean the local packages]' \
+        'docker[Subcommands specific to Docker use]'
+
+}