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.
These changes are inspired by the gf -cshell implementation of these commands.
The output of the linearize command has been changed to remove superfluous
blank lines and commas, and deliver the result as a list of strings instead of
a single multi-line string. This makes it possible to use -all and pipe the
results to the parse command. This also means that with -treebank -all,
the language tag will be repeated for each result from the same language.
The parse command, when trying to parse with more than one language, would
"forget" other results after a failed parse, and thus not send all
successful parses through the pipe. For example, if English is not the first
language in the grammar,
p "hello" | l
would output nothing, instead of translations of "hello" to all languages,
forcing the user to write
p -lang=Eng "hello" | l
instead, to get the expected result. The cause of this behaviour was in the
function fromParse, which was rather messy, so I assume it is not intentional,
but the result of a programming mistake at some point.
The fromParse function has now been refactored from a big recursive function
into
fromParse opts = foldr (joinPiped . fromParse1 opts) void
where the helper functions fromParse1 deals with a single parse result and
joinPiped combines multiple parse results.
Even though the -lang flag was handled in the implementation, it was not
documented, and GF.Command.Interpreter rejects undocumented flags:
option not interpreted: lang
This must be a fairly old bug, so it suggests that the vp command isn't used
much...
pg supports only the -funs, -cats and -langs output modes.
ai IDENTIFIER shows info about a category or a function. ai can not type check
and refine metavariables in expressions.
Options -all and -list use PGF2.linearizeAll, which lists all variants, but
not all forms...
Also, there is no attempt to be compatible with the output from the Haskell
run-rime shell, which produces superfluous blank lines (-all) or
commas (-list), and mixes tagged and untagged lines (-treebank -all).
+ 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}.
These commands are now implemented as regular commands (i.e. using the
CommandInfo data type) in the new module GF.Command.SourceCommands.
The list of commands exported from GF.Command.Commmands now called pgfCommands
instead of allCommands.
The list allCommands of all commands is now assembled
from sourceCommands, pgfCommands, commonCommands and helpCommand in
GF.Interactive.
Created module GF.Command.CommonCommands with ~250 lines of code for commands
that do not depend on the type of PGF in the environemnt, either because they
don't use the PGF or because they are just documented here and implemented
elsewhere.
TODO: further refactoring so that documentation and implementation of
*all* commands can be kept together.
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.
+ Move type CommandInfo from GF.Command.Commands to a new module
GF.Commands.CommandInfo and make it independent of the PGF type.
+ Make the module GF.Command.Interpreter independent of the PGF type and
eliminate the import of GF.Command.Commands.
+ Move the implementation of the "help" command to its own module
GF.Command.Help
Because the prompt included the name of the abstract syntax, the loading
of the PGF was forced even if -retain was used. Even worse,
if an error occured while loading the PGF, it was repeated and caught
every time the prompt was printed, creating an infite loop. The solution
is to not print the name of the abstract syntax when the grammar is
imported with -retain, which is the way things were before anyway.
Renamed appIOE to tryIOE (it is analogous to 'try' in the standard libraries).
Removed unused IOE operations & documented the remaining ones.
Removed/simplified superfluous uses of IOE operations.
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.
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.
When running a command like
gf -make L_1.gf ... L_n.gf
gf now avoids recreating the target PGF file if it already exists and is
up-to-date.
gf still reads all required .gfo files, so significant additional speed
improvements are still possible. This could be done by reading .gfo files
more lazily...
1. No temporary files are created.
2. The output of a system command is read lazily, making it feasible to
process large or even infinite output, e.g. the following works as
expected:
? "yes" | ? "head -5" | ps -lextext
The system_pipe (aka "?") command creates a temporary file _tmpi containing
the input of the system command. It *both* appends _tmpi as an extra argument
to the system command line *and* adds an input redirection "< _tmpi". (It
also uses and output redirection "> _tmpo" to captures the output of the
command.)
With this patch, the _tmpi argument is no longer appended to the command line.
This allows system_pipe to work with pure filters, such as the "tr" commands,
but it will no longer work with commands that require an input file name.
(It is possible to use write_file instead...)
TODO: it would also be fairly easy to eliminate the creation of the _tmpi and
_tmpo files altogether.
Trailing spaces caused the command line parse to be ambiguous, and
ambiguous parses were rejected by function readCommandLine, causing
the cryptic error message "command not parsed".
The only use of PGF.Tree outside the PGF library was in GF.Command.Commands,
and it was eliminated by using PGF.Expr directly instead.
PGF.Paraphrase still uses PGF.Tree.
