This patch fixes a problem introduced last year when the GF shell was
refactored to allow more commands to be treated uniformly and be part
of pipes. The cc command was one of those commands, but unfortunately this
introduced a parsing problem, e.g.
> cc "last"
constant not found: last
> cc "last"++"year"
command not parsed: cc "last"++"year"
This happened because the generic command line parser in
GF.Command.{Abstract,Parse} assumes that all commands have an argument of
type PGF.Expr. Commands that expect other types of arguments have to
use PGF.showExpr combined with other conversion to the argument type they
expect. The cc command excpets a GF.Grammar.Term, and unfortunately not
all terms survice the roundtrip through PGF.Expr, in part because of
an additional hack to allow strings to be roundtripped through PGF.Expr
without adding superfluous double quotes.
To solve the problem, this patch
+ makes room for arguments of type Term in the Argument type in
GF.Command.Abstract.
+ makes a special case for the cc command in GF.Command.Parse, by
calling the partial parser 'runPartial pTerm' recently added in
GF.Grammar.Lexer and GF.Grammar.Parser. Care was taken so that
that "|" and ";" can be used both inside terms and as separators between
commands in the shell, e.g. things like the following now work:
> cc ("a"|"b") | ps -lexcode
variants { "a" ; "b" }
+ introduces a type CommandArgument that replaces [Expr] as the
type of values passed between commands in pipes. It has room for
values of type [Expr], [String] and Term, thus eliminating the need
to roundtrip through the Expr type all the time.
The hack to avoid adding superfluous quotes when strings are
roundtripped through Expr has been left in place for now,
but can probably be removed.
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.
+ 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
+ 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%.
An apparent bug in ghc-7.2.2 causes the type Value to be exported from PGF.Data.
Workaround: restrict the imports from PGF.Data in GF.Command.Abstract and
GF.Compile.GeneratePMCFG to avoid the clash with locally defined type Value.
(ghc-7.0.4 and ghc-7.4.1 appear to be free from this bug.)
