Lexer.x: Change the parser monad type P to allow the remaining input to
be returned after a partial parse. Add function
runPartial :: P t -> String -> Either (Posn, String) (String, t)
Parser.y: Add a partial parser pTerm for nonterminal Exp1.
Re-export runPartial.
This makes the output from PGF.showExpr (and other Haskell code that uses
the Prelude.show function to show strings) parsable as GF source code in
more cases.
This is a workaround for the problem that GHC's implementation of the show
function uses numeric escapes for printable non-ASCII characters, e.g.
show "dålig" = "d\229lig"...
This was a fairly simple change thanks to previous work on making the Ident
type abstract and the fact that PGF.CId already uses UTF-8-encoded
ByteStrings.
One potential pitfall is that Data.ByteString.UTF8 uses the same type for
ByteStrings as Data.ByteString. I renamed ident2bs to ident2utf8 and
bsCId to utf8CId, to make it clearer that they work with UTF-8-encoded
ByteStrings.
Since both the compiler input and identifiers are now UTF-8-encoded
ByteStrings, the lexer now creates identifiers without copying any characters.
**END OF DESCRIPTION***
Place the long patch description above the ***END OF DESCRIPTION*** marker.
The first line of this file will be the patch name.
This patch contains the following changes:
M ./src/compiler/GF/Compile/CheckGrammar.hs -3 +3
M ./src/compiler/GF/Compile/GrammarToPGF.hs -2 +2
M ./src/compiler/GF/Grammar/Binary.hs -5 +1
M ./src/compiler/GF/Grammar/Lexer.x -11 +13
M ./src/compiler/GF/Infra/Ident.hs -19 +36
M ./src/runtime/haskell/PGF.hs -1 +1
M ./src/runtime/haskell/PGF/CId.hs -2 +3
1. The default encoding is changed from Latin-1 to UTF-8.
2. Alternate encodings should be specified as "--# -coding=enc", the old
"flags coding=enc" declarations have no effect but are still checked for
consistency.
3. A transitional warning is generated for files that contain non-ASCII
characters without specifying a character encoding:
"Warning: default encoding has changed from Latin-1 to UTF-8"
4. Conversion to Unicode is now done *before* lexing. This makes it possible
to allow arbitrary Unicode characters in identifiers. But identifiers are
still stored as ByteStrings, so they are limited to Latin-1 characters
for now.
5. Lexer.hs is no longer part of the repository. We now generate the lexer
from Lexer.x with alex>=3. Some workarounds for bugs in alex-3.0 were
needed. These bugs might already be fixed in newer versions of alex, but
we should be compatible with what is shipped in the Haskell Platform.
As a temporary workaround, alex is no longer invoked automatically when
building with cabal. Developers who want to modify the lexer need to run
alex on Lexer.x manually and record the modified Lexer.hs.
src/compiler/GF/Grammar/lexer/Lexer.x -- hidden from cabal
src/compiler/GF/Grammar/Lexer.hs -- update it manually
