+ Eliminated vairous ad-hoc coersion functions between specific monads
(IO, Err, IOE, Check) in favor of more general lifting functions
(liftIO, liftErr).
+ Generalized many basic monadic operations from specific monads to
arbitrary monads in the appropriate class (MonadIO and/or ErrorMonad),
thereby completely eliminating the need for lifting functions in lots
of places.
This can be considered a small step forward towards a cleaner
compiler API and more malleable compiler code in general.
+ 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 fact that identifiers are represented as ByteStrings is now an internal
implentation detail in module GF.Infra.Ident. Conversion between ByteString
and identifiers is only needed in the lexer and the Binary instances.
The refresh pass does not correctly keep track of the scope of local variables
and can convert things like \x->(\x->x) x into \x1->(\x2->x2) x2. Fortunately,
it appears that the refresh pass is not needed anymore, so it has been removed.
When compiling a grammar containing characters that are not supported in the
current locale, warning messages could cause GF fail with
hPutChar: invalid argument (Invalid or incomplete multibyte or wide character)
With this quick fix, warning messages that can not be displayed are silently
truncated instead, and compilation continues.
+ Instead of "Internal error in ...", you now get a proper error message with
a source location and a function name.
+ Also added some missing error value propagation in the partial evaluator.
+ Also some other minor cleanup and error handling fixes.
There was 55 lines of rather repetitive code with calls to 6 compiler passes.
They have been replaced with 19 lines that call the 6 compiler passes
plus 26 lines of helper functions.
This speeds up the compilation of PhrasebookFin.pgf by 12%, mosly by speeding
up calls to lookupModule in calls from lookupParamValues, in calls
from allParamValues.
The invariant "modules are stored in dependency order" is no longer respected!
But the type MGrammar is now abstract, making it easier to maintain this or
other invariants in the future.
