The implementation was meant to lift from SIO to IO,
but instead it was just the identity function,
which means that `fail = id . fail` and we have an infinite loop.
This output format converts a GF grammar to a "canonical" GF grammar. A
canonical GF grammar consists of
- one self-contained module for the abstract syntax
- one self-contained module per concrete syntax
The concrete syntax modules contain param, lincat and lin definitions,
everything else has been eliminated by the partial evaluator, including
references to resource library modules and functors. Record types
and tables are retained.
The -output-format canonical_gf option writes canonical GF grammars to a
subdirectory "canonical/". The canonical GF grammars are written as
normal GF ".gf" source files, which can be compiled with GF in the normal way.
The translation to canonical form goes via an AST for canonical GF grammars,
defined in GF.Grammar.Canonical. This is a simple, self-contained format that
doesn't cover everyting in GF (e.g. omitting dependent types and HOAS), but it
is complete enough to translate the Foods and Phrasebook grammars found in
gf-contrib. The AST is based on the GF grammar "GFCanonical" presented here:
https://github.com/GrammaticalFramework/gf-core/issues/30#issuecomment-453556553
The translation of concrete syntax to canonical form is based on the
previously existing translation of concrete syntax to Haskell, implemented
in module GF.Compile.ConcreteToHaskell. This module could now be reimplemented
and simplified significantly by going via the canonical format. Perhaps exports
to other output formats could benefit by going via the canonical format too.
There is also the possibility of completing the GFCanonical grammar
mentioned above and using GF itself to convert canonical GF grammars to
other formats...
Traditionally, GF_LIB_PATH points to something like
`.../share/ghc-8.0.2-x86_64/gf-3.9/lib`
and if you want prelude and alltenses and present, you add a
`--# -path=.:present`
compiler pragma to the top of your .gf file
But if you are developing some kind of application grammar
library or contrib of your own, you might find yourself
repeating your library path at the top of all your .gf files.
After painstakingly maintaining the same library path at the
top of all your .gf files, you might say, let's factor this
out into GF_LIB_PATH.
Then you might then find to your surprise that GF_LIB_PATH
doesn't accept the usual colon:separated:path notation
familiar from, say, unix PATH and MANPATH.
This patch allows you to define
`GF_LIB_PATH=gf-3.9.lib:$HOME/gf-contrib/whatever/lib`
in a more natural way.
If you are an RGL hacker and have your own version of the
RGL tree sitting somewhere, you should be able to have both
paths in the GF_LIB_PATH, for added convenience. This minor
convenience will probably lead to obscure bugs and great
frustration when you find that your changes are mysteriously
not being picked up by GF; so keep this in mind and use it
cautiously.
This caution should probably sit in the documentation
somewhere. A subsequent commit will do that.
If you use zsh, you can do this to quickly build up a big
GF_LIB_PATH:
% gf_lib_path=( $HOME/src/GF/lib/src/{api,abstract,common,english,api/libraryBrowser,prelude,..} )
% typeset -xT GF_LIB_PATH gf_lib_path
* In GHC 8.4.1, the operator <> has become a method of the Semigroup class
and is exported from the Prelude. This is unfortunate, since <> is also
exported from the standard library module Text.PrettyPrint, so in any
module that defines a pretty printer, there is likely to be an ambiguity.
This affects ~18 modules in GF. Solution:
import Prelude hiding (<>)
This works also in older versions of GHC, since GHC does't complain if
you hide something that doesn't exists.
* In GHC 8.4.1, Semigroup has become a superclass of Monoid. This means
that anywhere you define an instance of the Monoid class you also have to
define an instance in the Semigroup class.
This affects Data.Binary.Builder in GF. Solution: conditionally define
a Semigroup instance if compiling with base>=4.11 (ghc>=8.4.1)
+ Generalize the CommandInfo type by parameterizing it on the monad
instead of just the environment.
+ Generalize the commands defined in
GF.Command.{Commands,Commands2,CommonCommands,SourceCommands,HelpCommand}
to work in any monad that supports the needed operations.
+ Liberate GF.Command.Interpreter from the IO monad.
Also, move the current PGF from CommandEnv to GFEnv in
GF.Interactive, making the command interpreter even more generic.
+ Use a state monad to maintain the state of the interpreter in
GF.{Interactive,Interactive2}.
Some C run-time functionality is now available in the GF shell, by starting
GF with 'gf -cshell' or 'gf -crun'. Only limited functionality is available
when running the shell in these modes:
- You can only import .pgf files, not source files.
- The -retain flag can not be used and the commands that require it to work
are not available.
- Only 18 of the 40 commands available in the usual shell have been
implemented. The 'linearize' and 'parse' commands are the only ones
that call the C run-time system, and they support only a limited set of
options and flags. Use the 'help' commmands for details.
- A new command 'generate_all', that calls PGF2.generateAll, has been added.
Unfortuntaly, using it causes 'segmentation fault'.
This is implemented by adding two new modules: GF.Command.Commands2 and
GF.Interactive2. They are copied and modified versions of GF.Command.Commands
and GF.Interactive, respectively. Code for unimplemented commands and other
code that has not been adapted to the C run-time system has been left in
place, but commented out, pending further work.
