Updates command registration to provide top-level handlers for all
commands, rather than falling back onto the 'unknown' command. Instead,
that same handler is registered for placeholders, providing the same
functionality under the root verb command name instead. This permits
users to implement their own 'unknown' function, and it resolves some
mind-bending breakage related to function object lookup while recursing.
Changes 'ocd_bounce' to call 'ocd_command' and 'ocd_help' from the
wrapper directly, rather than bouncing through their wrappers. This
prevents endless recursion caused by the above changes, whereby the
'command' wrapper's type check would blow the stack to hell and gone.
Adds 'ocd_bouncer' in startup.tcl that is called as a helper for
all command handlers, shrinking the embedded C wrapper to a mere stub.
Jim handlers are called directly, simple handlers get called with the
wrapper to capture and discard their output on error, and placeholders
call help directly (though the unknown handler still does this too).
It attempts to improve the quality of the error messages as well.
Adds the 'command' group handler, with the 'type' command producing
a string that tells whether the given command is 'native' (for Jim-based
command handlers), 'simple' (for simple built-in commands), 'group'
for command group placeholders, and 'unknown' if not found in the
command registration tables (e.g. core built-ins functions).
The command refactoring caused subcommand handlers to produce duplicate
output when run. The problem was introduced by failing to ensure all
such invocations went through a top-level "catcher" script, prefixing
the command name with the 'ocd_' prefix and consuming its results.
The fix is to ensure such a top-level "catcher" script gets created
for each top-level command, regardless of whether it has a handler.
Indeed, this patch removes all command registrations for sub-commands,
which would not have worked in the new registration scheme anyway.
For now, dispatch of subcommands continues to be handled by the new
'unknown' command handler, which gets fixed here to strip the 'ocd_'
prefix if searching for the top-level command name fails initially.
Some Jim commands may be registered with this prefix, and that situation
seems to require the current fallback approach. Otherwise, that prefix
could be stripped unconditionally and the logic made a little simpler.
The same problem must be handled by the 'help' command handler too,
so its lookup process works as intended.
Overall, the command dispatching remains more complicated than desired,
but this patch fixes the immediate regressions.
Factors log capture while running script commands, eliminating
duplicated code between script_command and jim_capture. Factors
setting a command's Jim "retval" into a new helper as well.
Using these new helpers in the new unknown command handler's
fixes possible regressions caused by these bits being missing.
The add_usage_text command uses the same C handler, which was updated
to support its new polymorphic role. This patch updates the two script
commands that needed this support: 'find' and 'script'.
Adding jim_handler field to command_registration allows removing the
register_jim helper. All command registrations now go through the
register_command{,s}() functions.
Adds the ability to chain registration structures. Modules can define a
command with the 'chain' and 'num_chain' fields defined in their
registration table, and the register_commands() function will initialize
these commands. If the registration record creates a new command, then
the chained commands are created under it; otherwise, they are created
in the same context as the other commands (i.e. the parent argument).
Use register_commands() to register low-level command handlers,
adding a builtin_command_handlers declaration that is easy to understand.
Splits help and usage information into their appropriate fields.
Adds the usage command, to display usage information for commands.
The output for this command will remain erronenously empty until
commands are updated to use these new coventions.
The register_commands API takes multiple commands in one call, allowing
modules to declare and pass a much simpler (and more explicit) array of
command_registration records.
Add a structure to encapsulate command registration information, rather
than passing them all as parameters. Enables further API changes that
require additional required or optional parameters.
Updates the register_command API and COMMAND_REGISTER macro to use it,
along with their documentation.
Rewrite means for scripts to register help text for commands. These
cause the new commands to be stored in the command heirarchy, with
built-in commands; however, they will never be invoked there because
they do not receive a command handler. The same trick is used for
the Jim commands.
Remove the old helpers that were used to register commands.
For the startup.tcl code to use built-in commands, the context must be
associated with the interpreter temporarily. This will be required to
add help text.
Rewrites 'help' command in C, using new 'cmd_help' for display. Adds the
built-in 'help' COMMAND_HANDLER to provide better output than the
TCL-based script command (e.g. heirarchical listing of commands).
The help string is stored in the command structure, though it conitnues
to be pushed into the Jim environment. The current idiomatic usage
suggests the addition of a usage field as well, to provide two levels
of detail for users to consume (i.e. terse usage list, or verbose help).
