Add backward compatibility for reading old PGF files

Some backwards incompatible changes were made to the PGF file format after
the release of GF 3.5. This patch adds a module for reading PGF files in the
old format.

This means that old PGF files on the grammaticalframework.org server will
continue to work after we install the latest version of GF.

1 files changed, 8 insertions, 3 deletions

diff --git a/src/runtime/haskell/PGF/Binary.hs b/src/runtime/haskell/PGF/Binary.hs
index e2403809e..4d4c53102 100644
--- a/src/runtime/haskell/PGF/Binary.hs
+++ b/src/runtime/haskell/PGF/Binary.hs
@@ -1,8 +1,9 @@
-module PGF.Binary where

+module PGF.Binary(putSplitAbs) where

 

 import PGF.CId

 import PGF.Data

 import PGF.Optimize

+import qualified PGF.OldBinary as Old

 import Data.Binary

 import Data.Binary.Put

 import Data.Binary.Get

@@ -14,7 +15,7 @@ import qualified Data.IntMap as IntMap
 import Control.Monad

 

 pgfMajorVersion, pgfMinorVersion :: Word16

-(pgfMajorVersion, pgfMinorVersion) = (2,0)

+version@(pgfMajorVersion, pgfMinorVersion) = (2,0)

 

 instance Binary PGF where

   put pgf = do putWord16be pgfMajorVersion

@@ -24,7 +25,11 @@ instance Binary PGF where
                put (concretes pgf)

   get = do v1 <- getWord16be

            v2 <- getWord16be

-           gflags <- get

+           case (v1,v2) of

+             v | v==version -> getPGF'

+               | v==Old.version -> Old.getPGF'

+

+getPGF'=do gflags <- get

            (absname,abstract) <- get

            concretes <- get

            return $ updateProductionIndices $