Becacuse of the new special tokens added to the Symbol type, .gfo and .pgf
files produced with the current version of GF can not always be used with
older versions of GF and the PGF run-time system.
The PGF version number was increased from (2,0) to (2,1). GF can still
read version (2,0) and (1,0), so old PGF files continue to work.
The GFO version was increased from "GF03" to "GF04".
The def rules are now compiled to byte code by the compiler and then to
native code by the JIT compiler in the runtime. Not all constructions
are implemented yet. The partial implementation is now in the repository
but it is not activated by default since this requires changes in the
PGF format. I will enable it only after it is complete.
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.
+ 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%.
The following are the outcomes:
- Predef.nonExist is fully supported by both the Haskell and the C runtimes
- Predef.BIND is now an internal compiler defined token. For now
it behaves just as usual for the Haskell runtime, i.e. it generates &+.
However, the special treatment will let us to handle it properly in
the C runtime.
- This required a major change in the PGF format since both
nonExist and BIND may appear inside 'pre' and this was not supported
before.
