Experiment with parallel grammar checks

Introduced the function

	parallelCheck :: [Check a] -> Check [a]

that runs independent checks in parallel, potentially allowing faster grammar
compilation on multi-core computers, if you run gf with +RTS -N.

However, on my dual core laptop, this seems to slow down compilation somewhat
even though CPU utilization goes up as high as 170% at times.
(This is with GF compiled with GHC 7.0.4.)

1 files changed, 3 insertions, 1 deletions

diff --git a/gf.cabal b/gf.cabal
index 4cbc24a96..ae1d73774 100644
--- a/gf.cabal
+++ b/gf.cabal
@@ -108,7 +108,9 @@ executable gf
                  process,
                  pretty,
                  mtl,
-                 haskeline
+                 haskeline,
+                 parallel
+  ghc-options: -threaded
   if flag(server)
     build-depends: httpd-shed, network, silently, utf8-string, json, cgi
     cpp-options: -DSERVER_MODE