add build caching

appveyor.yml

@@ -8,21 +8,22 @@ environment:
     GHC_OPTIONS: "-O0 -Werror"
 
     STACK_ROOT: "c:\\sr"
-    #PATH: "c:\\sr"
+    LOCAL_BIN: "%APPDATA%\\local\\bin"
     PATH: "%PATH%;%APPDATA%\\local\\bin"
     CABAL_REINIT_CONFIG: "y"
 
-    #cache:
-  #- "c:\\sr" # stack root
-  #- "%APPDATA%\\local"
-  #- "%APPDATA%\\cabal"
-  #- "%APPDATA%\\ghc"
+cache:
+  - "%STACK_ROOT%" # stack root
+  - "%LOCALAPPDATA%\\Programs\\stack" # ghc & msys
+  - "%LOCAL_BIN%"
+  - "%APPDATA%\\cabal"
+  - "%APPDATA%\\ghc"
 
 build: off
 
 before_test:
-- mkdir %APPDATA%\\local\\bin
-- where stack.exe || curl -sSkL -ostack.zip http://www.stackage.org/stack/windows-i386 && 7z x stack.zip stack.exe && move stack.exe %APPDATA%\\local\\bin
+- if not exist %LOCAL_BIN% mkdir %LOCAL_BIN%
+- where stack.exe || curl -sSkL -ostack.zip http://www.stackage.org/stack/windows-i386 && 7z x stack.zip stack.exe && move stack.exe %LOCAL_BIN%
 - curl -sSkL -opackage-sanity.sh https://raw.githubusercontent.com/harendra-kumar/package-sanity/windows/package-sanity.sh
 
 test_script: