This is implemented as a simple post-processing step after partial evaluation
to try compute pre{...} tokens in token sequences. Nothing is done to deal
with intervening free variants.
This was done in response to a query from René T on the gf-dev mailing list.
If the enumaration of table parameter values fails during the static
traversal phase, try again in the dynamic computation phase, when the values
of bound variables are known.
This is necessary to properly deal with generic table construction in opers,
like the ones found in prelude/Coordination.gf, e.g.
consTable : (P : PType) -> ... = \P ... -> {s1 = table P {...} ; ... }
2 modules: Name clashes caused by Applicative-Monad change in Prelude
2 modules: Ambiguities caused by Foldable/Traversable in Prelude
2 modules: Backwards incompatible changes in time-1.5 for defaultTimeLocale
9 modules: {-# LANGUAGE FlexibleContexts #-} (because GHC checks inferred types
now, in addition to explicitly given type signatures)
Also silenced warnings about tab characters in source files.
It was used only in cases where a lock field needed to be added to a
run-time variable, like e.g. in examples/phrasebook/SentencesTha.gf:
lin
PGreetingMale g = mkText (lin Text g) (lin Text (ss "ครับ")) | g ;
PGreetingFemale g = mkText (lin Text g) (lin Text (ss "ค่ะ")) | g ;
But lock fields are only meaningful during type checking and can safely be
ignored in later passes.
* The following modules are no longer used and have been removed completely:
GF.Compile.Compute.ConcreteLazy
GF.Compile.Compute.ConcreteStrict
GF.Compile.Refresh
* The STM monad has been commented out. It was only used in
GF.Compile.SubExpOpt, where could be replaced with a plain State monad,
since no error handling was needed. One of the functions was hardwired to
the Err monad, but did in fact not use error handling, so it was turned
into a pure function.
* The function errVal has been renamed to fromErr (since it is analogous to
fromMaybe).
* Replaced 'fail' with 'raise' and 'return ()' with 'done' in a few places.
* Some additional old code that was already commented out has been removed.
GF.Text.Pretty provides the class Pretty and overloaded versions of the pretty
printing combinators in Text.PrettyPrint, allowing pretty printable values to
be used directly instead of first having to convert them to Doc with functions
like text, int, char and ppIdent. Some modules have been converted to use
GF.Text.Pretty, but not all. Precedences could be added to simplify the pretty
printers for terms and patterns.
GF.Infra.Location contains the types Location and L, factored out from
GF.Grammar.Grammar, and the class HasSourcePath. This allowed the import
of GF.Grammar.Grammar to be removed from GF.Infra.CheckM, making it more
like a pure library module.
PGF exports the public, stable API.
PGF.Internal exports additional things needed in the GF compiler & shell,
including the nonstardard version of Data.Binary.
(table { p_i => t_i } ! x).l ==> table { p_i => t_i.l } ! x
This was used in the old partial evaluator and can significantly reduce term
sizes in some cases.
This means that the -old-comp and -new-comp flags are not recognized anymore.
The only functional difference is that printnames were still normalized with
the old partial evaluator. Now that is done with the new partial evaluator.
+ 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.
Most of the explicit uses of ByteStrings were eliminated by using identS,
identS = identC . BS.pack
which was found in GF.Grammar.CF and moved to GF.Infra.Ident. The function
prefixIdent :: String -> Ident -> Ident
allowed one additional import of ByteString to be eliminated. The functions
isArgIdent :: Ident -> Bool
getArgIndex :: Ident -> Maybe Int
were needed to eliminate explicit pattern matching on Ident from two modules.
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.
This should prevent errors like
Internal error in Compute.ConcreteNew:
Applying Predef.drop: Expected a value of type String, got VFV [VString "gewandt",VString "gewendet"]
The sequence operator (x+y) was implemented by splitting the string to be
matched at all positions and trying to match the parts against the two
subpatterns. To reduce the number of splits, we now estimate the minimum and
maximum length of the string that the subpatterns could match. For common
cases, where one of the subpatterns is a string of known length, like
in (x+"y") or (x + ("a"|"o"|"u"|"e")+"y"), only one split will be tried.
+ 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.
It failed to delay table selection when the selector contains a run-time
variable, causing "gf: Prelude.(!!): index too large" instead.
Also:
+ Show better source locations on unexpected errors, to aid bug hunting.
+ Removed unused SourceGrammar argument to value2term.
The work done by the partial evaluator is now divied in two stages:
- A static "term traversal" stage that happens only once per term and uses
only statically known information. In particular, the values of lambda bound
variables are unknown during this stage. Some tables are transformed to
reduce the cost of pattern matching.
- A dynamic "function application" stage, where function bodies can be
evaluated repeatedly with different arguments, without the term traversal
overhead and without recomputing statically known information.
Also the treatment of predefined functions has been reworked to take advantage
of the staging and better handle partial applications.
* Evaluate operators once, not every time they are looked up
* Remember the list of parameter values instead of recomputing it from the
pattern type every time a table selection is made.
* Quick fix for partial application of some predefined functions.
