[commit: ghc] wip/nfs-locking: Add a paragraph on customising progress messages (2c77b71)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : wip/nfs-locking
Link       : http://ghc.haskell.org/trac/ghc/changeset/2c77b7107ccf663598b9b64a22f3a4c5bc39b568/ghc

>---------------------------------------------------------------

commit 2c77b7107ccf663598b9b64a22f3a4c5bc39b568
Author: Andrey Mokhov <andrey.mokhov at gmail.com>
Date:   Tue May 17 23:55:16 2016 +0100

    Add a paragraph on customising progress messages
    
    See #244. [skip ci]


>---------------------------------------------------------------

2c77b7107ccf663598b9b64a22f3a4c5bc39b568
 doc/user-settings.md | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/doc/user-settings.md b/doc/user-settings.md
index 4624e2d..1433ae9 100644
--- a/doc/user-settings.md
+++ b/doc/user-settings.md
@@ -144,3 +144,20 @@ splitObjects = (return cmdSplitObjects) &&^ defaultSplitObjects
 buildHaddock :: Predicate
 buildHaddock = return cmdBuildHaddock
 ```
+
+Hadrian prints various progress info during the build. You can customise how this
+info is printed by overriding `putBuild` and `putSuccess` commands:
+
+```haskell
+-- | Customise build progress messages (e.g. executing a build command).
+putBuild :: String -> Action ()
+putBuild = putColoured Vivid White
+
+-- | Customise build success messages (e.g. a package is built successfully).
+putSuccess :: String -> Action ()
+putSuccess = putColoured Vivid Green
+```
+
+You can tune colours for your favourite terminal and also change the verbosity
+level, e.g. by setting `putSuccess = putLoud`, which will hide success messages
+unless Hadrian is called with `--verbose` flag.