Eliminate mutual dependencies between the GF compiler and the PGF library

+ References to modules under src/compiler have been eliminated from the PGF
  library (under src/runtime/haskell). Only two functions had to be moved (from
  GF.Data.Utilities to PGF.Utilities) to make this possible, other apparent
  dependencies turned out to be vacuous.

+ In gf.cabal, the GF executable no longer directly depends on the PGF library
  source directory, but only on the exposed library modules. This means that
  there is less duplication in gf.cabal and that the 30 modules in the
  PGF library will no longer be compiled twice while building GF.

  To make this possible, additional PGF library modules have been exposed, even
  though they should probably be considered for internal use only. They could
  be collected in a PGF.Internal module, or marked as "unstable", to make
  this explicit.

+ Also, by using the -fwarn-unused-imports flag, ~220 redundant imports were
  found and removed, reducing the total number of imports by ~15%.

1 files changed, 0 insertions, 3 deletions

diff --git a/src/compiler/GFI.hs b/src/compiler/GFI.hs
index 7c53ed8d8..1a786a3d2 100644
--- a/src/compiler/GFI.hs
+++ b/src/compiler/GFI.hs
@@ -13,7 +13,6 @@ import GF.Data.Operations (chunks,err)
 import GF.Grammar hiding (Ident,isPrefixOf)
 import GF.Grammar.Analyse
 import GF.Grammar.Parser (runP, pExp)
-import GF.Grammar.Printer (ppGrammar, ppModule)
 import GF.Grammar.ShowTerm
 import GF.Grammar.Lookup (allOpers,allOpersTo)
 import GF.Compile.Rename(renameSourceTerm)
@@ -25,7 +24,6 @@ import GF.Infra.CheckM
 import GF.Infra.UseIO(ioErrorText)
 import GF.Infra.SIO
 import GF.Infra.Option
-import GF.Infra.Ident (showIdent)
 import qualified System.Console.Haskeline as Haskeline
 import GF.Text.Coding(decodeUnicode,encodeUnicode)
 
@@ -36,7 +34,6 @@ import PGF.Data
 import PGF.Macros
 
 import Data.Char
-import Data.Maybe
 import Data.List(nub,isPrefixOf,isInfixOf,partition)
 import qualified Data.Map as Map
 import qualified Data.ByteString.Char8 as BS