page_pluginmgr -
page plugin manager
package require page::pluginmgr ? 0.2 ?
package require fileutil
::page::pluginmgr::reportvia cmd
::page::pluginmgr::report level text ? from ? to ? ?
::page::pluginmgr::log cmd
::page::pluginmgr::configuration name
::page::pluginmgr::reader name
::page::pluginmgr::rconfigure dict
::page::pluginmgr::rtimeable
::page::pluginmgr::rtime
::page::pluginmgr::rgettime
::page::pluginmgr::rhelp
::page::pluginmgr::rlabel
::page::pluginmgr::read read eof ? complete ?
read num
eof
done
::page::pluginmgr::writer name
::page::pluginmgr::wconfigure dict
::page::pluginmgr::wtimeable
::page::pluginmgr::wtime
::page::pluginmgr::wgettime
::page::pluginmgr::whelp
::page::pluginmgr::wlabel
::page::pluginmgr::write chan data
::page::pluginmgr::transform name
::page::pluginmgr::tconfigure id dict
::page::pluginmgr::ttimeable id
::page::pluginmgr::ttime id
::page::pluginmgr::tgettime id
::page::pluginmgr::thelp id
::page::pluginmgr::tlabel id
::page::pluginmgr::transform_do id data
page_cdefinition
page_rfeature name
page_rtime
page_rgettime
page_rlabel
page_rhelp
page_roptions
page_rconfigure option value
page_rrun
page_read num
page_read_done
page_eof
page_info text ? from ? to ? ?
page_warning text ? from ? to ? ?
page_error text ? from ? to ? ?
page_log_info text
page_log_warning text
page_log_error text
page_wfeature
page_wtime
page_wgettime
page_wlabel
page_whelp
page_woptions
page_wconfigure option value
page_wrun chan data
page_info text ? from ? to ? ?
page_warning text ? from ? to ? ?
page_error text ? from ? to ? ?
page_log_info text
page_log_warning text
page_log_error text
page_tfeature
page_ttime
page_tgettime
page_tlabel
page_thelp
page_toptions
page_tconfigure option value
page_trun chan data
page_info text ? from ? to ? ?
page_warning text ? from ? to ? ?
page_error text ? from ? to ? ?
page_log_info text
page_log_warning text
page_log_error text
This package provides the plugin manager central to the page
application. It manages the various reader, writer, configuration, and
transformation plugins which actually process the text (read,
transform, and write).
All plugins are loaded into slave interpreters specially prepared for
them. While implemented using packages they need this special
environment and are not usable in a plain interpreter, like
tclsh. Because of that they are only described in general terms in
section PREDEFINED PLUGINS, and not documented as regular
packages. It is expected that they follow the APIs specified in the
sections
- CONFIG PLUGIN API
- READER PLUGIN API
- WRITER PLUGIN API
- TRANSFORM PLUGIN API
as per their type.
-
::page::pluginmgr::reportvia cmd
-
This command defines the callback command used by
::page::pluginmgr::report (see below) to report input errors and
warnings. The default is to write such reports to the standard error
channel.
-
::page::pluginmgr::report level text ? from ? to ? ?
-
This command is used to report input errors and warnings. By default
such reports are written to the standard error. This can be changed by
setting a user-specific callback command with
::page::pluginmgr::reportvia (see above).
The arguments level and text specify both the importance
of the message, and the message itself. For the former see the package
logger for the allowed values.
The optional argument from and to can be used by the
caller to indicate the location (or range) in the input where the
reported problem occured. Each is a list containing two elements, the
line and the column in the input, in this order.
-
::page::pluginmgr::log cmd
-
This command defines a log callback command to be used by loaded
plugins for the reporting of internal errors, warnings, and general
information. Specifying the empty string as callback disables logging.
Note: The cmd has to be created by the logger package,
or follow the same API as such.
The command returns the empty string as its result.
-
::page::pluginmgr::configuration name
-
This command loads the named configuration plugin, retrieves the
options encoded in it, and then immediately unloads it again.
If the name is the path to a file, then this files will be tried
to be loaded as a plugin first, and, if that fails, opened and its
contents read as a list of options and their arguments, separated by
spaces, tabs and newlines, possibly quotes with single and double
quotes.
See section CONFIG PLUGIN API for the API expected of
configuration plugins.
The result of the command is the list of options retrieved.
-
::page::pluginmgr::reader name
-
This command loads the named reader plugin and initializes it. The
result of the command is a list of options the plugin understands.
Only a single reader plugin can be loaded. Loading another reader
plugin causes the previously loaded reader plugin to be de-initialized
and unloaded.
See section READER PLUGIN API for the API expected of
reader plugins.
-
::page::pluginmgr::rconfigure dict
-
This commands configures the loaded reader plugin. The options and
their values are provided as a Tcl dictionary. The result of the
command is the empty string.
-
::page::pluginmgr::rtimeable
-
This commands checks if the loaded reader plugin is able to collect
timing statistics. The result of the command is a boolean flag. The
result is true if the plugin can be timed, and false
otherwise.
-
::page::pluginmgr::rtime
-
This command activates the collection of timing statistics in the
loaded reader plugin.
-
::page::pluginmgr::rgettime
-
This command retrieves the collected timing statistics of the loaded
reader plugin after it was executed.
-
::page::pluginmgr::rhelp
-
This command retrieves the help string of the loaded reader
plugin. This is expected to be in doctools format.
-
::page::pluginmgr::rlabel
-
This command retrieves the human-readable name of the loaded reader
plugin.
-
::page::pluginmgr::read read eof ? complete ?
-
This command invokes the loaded reader plugin to process the input,
and returns the results of the plugin as its own result. The input is
accessible through the callback commands read, and eof. The
optional done can be used to intrecept when the plugin has
completed its processing. All arguments are command prefixes.
The plugin will invoke the various callbacks in the following
situations:
-
read num
-
is invoked whenever input to process is needed, with the number of
characters/bytes it asks for. The result is expected to be the input
the plugin is in need of.
-
eof
-
is invoked by the plugin to check if the input has reached the of the
stream. The result is expected to be a boolean flag, true when
the input has hit EOF, and false otherwise.
-
done
-
is invoked when the plugin has completed the processing of the input.
-
::page::pluginmgr::writer name
-
This command loads the named writer plugin and initializes it. The
result of the command is a list of options the plugin understands.
Only a single reader plugin can be loaded. Loading another reader
plugin causes the previously loaded reader plugin to be de-initialized
and unloaded.
See section WRITER PLUGIN API for the API expected of
writer plugins.
-
::page::pluginmgr::wconfigure dict
-
This commands configures the loaded writer plugin. The options and
their values are provided as a Tcl dictionary. The result of the
command is the empty string.
-
::page::pluginmgr::wtimeable
-
This commands checks if the loaded writer plugin is able to measure
execution times. The result of the command is a boolean flag. The
result is true if the plugin can be timed, and false
otherwise.
-
::page::pluginmgr::wtime
-
This command activates the collection of timing statistics in the
loaded writer plugin.
-
::page::pluginmgr::wgettime
-
This command retrieves the collected timing statistics of the loaded
writer plugin after it was executed.
-
::page::pluginmgr::whelp
-
This command retrieves the help string of the loaded writer
plugin. This is expected to be in doctools format.
-
::page::pluginmgr::wlabel
-
This command retrieves the human-readable name of the loaded writer
plugin.
-
::page::pluginmgr::write chan data
-
The loaded writer plugin is invoked to generate the output. It is
given the data to generate the outpout from, and the Tcl handle
chan of the channel to write the generated output to. The
command returns th empty string as its result.
-
::page::pluginmgr::transform name
-
This command loads the named transformation plugin and initializes
it. The result of the command is a 2-element list containing the
plugin id and a list of options the plugin understands, in this order.
Multiple transformations plugins can be loaded and are identified by
handles.
See section TRANSFORM PLUGIN API for the API expected of
transformation plugins.
-
::page::pluginmgr::tconfigure id dict
-
This commands configures the identified transformation plugin. The
options and their values are provided as a Tcl dictionary. The result
of the command is the empty string.
-
::page::pluginmgr::ttimeable id
-
This commands checks if the identified transformation plugin is able
to collect timing statistics. The result of the command is a boolean
flag. The result is true if the plugin can be timed, and
false otherwise.
-
::page::pluginmgr::ttime id
-
This command activates the collection of timing statistics in the
identified transformation plugin.
-
::page::pluginmgr::tgettime id
-
This command retrieves the collected timing statistics of the
identified transformation plugin after it was executed.
-
::page::pluginmgr::thelp id
-
This command retrieves the help string of the identified
transformation plugin. This is expected to be in doctools
format.
-
::page::pluginmgr::tlabel id
-
This command retrieves the human-readable name of the identified
transformation plugin.
-
::page::pluginmgr::transform_do id data
-
The identified transformation plugin is invoked to process the
specified data. The result of the plugin is returned as the
result of the command.
Configuration plugins are expected to provide a single command,
described below.
-
page_cdefinition
-
This command of a configuration plugin is called by the plugin manager
to execute it. Its result has to be a list of options and values to
process.
Configuration plugins do not expect the environment to provide any
special commands.
It is expected that a configuration plugin FOO is implemented
by the package page::config::FOO
.
Configuration plugins are loaded, executed, and unloaded in one step,
they are not kept in memory. The command for doing this is
::page::pluginmgr::configuration.
Reader plugins are expected to provide the following commands,
described below.
-
page_rfeature name
-
This command takes a feature name and returns a boolean flag
indicating whether the feature is supported by the plugin, or not.
The result has to be true if the feature is supported, and
false otherwise.
See section FEATURES for the possible features the plugin
manager will ask for.
-
page_rtime
-
This command is invoked to activate the collection of timing
statistics.
-
page_rgettime
-
This command is invoked to retrieve the collected timing statistics.
-
page_rlabel
-
This command is invoked to retrieve a human-readable label for the
plugin.
-
page_rhelp
-
This command is invoked to retrieve a help text for plugin. The text
is expected to be in doctools format.
-
page_roptions
-
This command is invoked to retrieve the options understood by the
plugin.
-
page_rconfigure option value
-
This command is invoked to reconfigure the plugin, specifically the
given option is set to the new value.
-
page_rrun
-
This command is invoked to process the input stream per the current
plugin configuration. The result of the command is the result of the
processing.
Reader plugins expect the environment to provide the following special
commands.
-
page_read num
-
This command is invoked to read num characters/bytes from the
input. Its result has to be read characters/bytes.
-
page_read_done
-
This command is invoked to signal that the plugin has completed the
processing of the input.
-
page_eof
-
This command is invoked to check if the input stream has reached its
end. Its result has to be a boolean flag, true when the input
has reached the end, false otherwise.
-
page_info text ? from ? to ? ?
-
Invoked to report some information to the user. May indicate a
location or range in the input. Each piece of location data, if
provided, is a 2-element list containing line and column numbers.
-
page_warning text ? from ? to ? ?
-
Invoked to report a warning to the user. May indicate a location or
range in the input. Each piece of location data, if provided, is a
2-element list containing line and column numbers.
-
page_error text ? from ? to ? ?
-
Invoked to report an error to the user. May indicate a location or
range in the input. Each piece of location data, if provided, is a
2-element list containing line and column numbers.
-
page_log_info text
-
Invoked to report some internal information.
-
page_log_warning text
-
Invoked to report an internal warning.
-
page_log_error text
-
Invoked to report an internal error.
It is expected that a reader plugin FOO is implemented
by the package page::reader::FOO
.
Reader plugins are loaded by the command
::page::pluginmgr::reader. At most one reader plugin can be kept
in memory.
Writer plugins are expected to provide the following commands,
described below.
-
page_wfeature
-
This command takes a feature name and returns a boolean flag
indicating whether the feature is supported by the plugin, or not.
The result has to be true if the feature is supported, and
false otherwise.
See section FEATURES for the possible features the plugin
manager will ask for.
-
page_wtime
-
This command is invoked to activate the collection of timing
statistics.
-
page_wgettime
-
This command is invoked to retrieve the collected timing statistics.
-
page_wlabel
-
This command is invoked to retrieve a human-readable label for the
plugin.
-
page_whelp
-
This command is invoked to retrieve a help text for plugin. The text
is expected to be in doctools format.
-
page_woptions
-
This command is invoked to retrieve the options understood by the
plugin.
-
page_wconfigure option value
-
This command is invoked to reconfigure the plugin, specifically the
given option is set to the new value.
-
page_wrun chan data
-
This command is invoked to process the specified data and write
it to the output stream chan. The latter is a Tcl channel handle
opened for writing. The result of the command is the empty string.
Writer plugins expect the environment to provide the following special
commands.
-
page_info text ? from ? to ? ?
-
Invoked to report some information to the user. May indicate a
location or range in the input. Each piece of location data, if
provided, is a 2-element list containing line and column numbers.
-
page_warning text ? from ? to ? ?
-
Invoked to report a warning to the user. May indicate a location or
range in the input. Each piece of location data, if provided, is a
2-element list containing line and column numbers.
-
page_error text ? from ? to ? ?
-
Invoked to report an error to the user. May indicate a location or
range in the input. Each piece of location data, if provided, is a
2-element list containing line and column numbers.
-
page_log_info text
-
Invoked to report some internal information.
-
page_log_warning text
-
Invoked to report an internal warning.
-
page_log_error text
-
Invoked to report an internal error.
It is expected that a writer plugin FOO is implemented
by the package page::writer::FOO
.
Writer plugins are loaded by the command
::page::pluginmgr::writer. At most one writer plugin can be kept
in memory.
page::transform::*
Transformation plugins are expected to provide the following commands,
described below.
-
page_tfeature
-
This command takes a feature name and returns a boolean flag
indicating whether the feature is supported by the plugin, or not.
The result has to be true if the feature is supported, and
false otherwise.
See section FEATURES for the possible features the plugin
manager will ask for.
-
page_ttime
-
This command is invoked to activate the collection of timing
statistics.
-
page_tgettime
-
This command is invoked to retrieve the collected timing statistics.
-
page_tlabel
-
This command is invoked to retrieve a human-readable label for the
plugin.
-
page_thelp
-
This command is invoked to retrieve a help text for plugin. The text
is expected to be in doctools format.
-
page_toptions
-
This command is invoked to retrieve the options understood by the
plugin.
-
page_tconfigure option value
-
This command is invoked to reconfigure the plugin, specifically the
given option is set to the new value.
-
page_trun chan data
-
This command is invoked to process the specified data and write
it to the output stream chan. The latter is a Tcl channel handle
opened for writing. The result of the command is the empty string.
Transformation plugins expect the environment to provide the following
special commands.
-
page_info text ? from ? to ? ?
-
Invoked to report some information to the user. May indicate a
location or range in the input. Each piece of location data, if
provided, is a 2-element list containing line and column numbers.
-
page_warning text ? from ? to ? ?
-
Invoked to report a warning to the user. May indicate a location or
range in the input. Each piece of location data, if provided, is a
2-element list containing line and column numbers.
-
page_error text ? from ? to ? ?
-
Invoked to report an error to the user. May indicate a location or
range in the input. Each piece of location data, if provided, is a
2-element list containing line and column numbers.
-
page_log_info text
-
Invoked to report some internal information.
-
page_log_warning text
-
Invoked to report an internal warning.
-
page_log_error text
-
Invoked to report an internal error.
It is expected that a transformation plugin FOO is implemented
by the package page::transform::FOO
.
Transformation plugins are loaded by the command
::page::pluginmgr::transform. More than one transformation
plugin can be kept in memory.
The following predefined plugins are known, i.e. provided by the page
module.
- Configuration
-
- peg
-
Returns a set of options to configure the page application
for the processing of a PEG grammar and the generation of ME code. See
the packages grammar_peg, grammar_me and relations
for more details.
- Reader
-
- hb
-
Expects a so-called half-baked PEG container as input and
returns the equivalent abstract syntax tree. See the writer plugin
hb for the plugin generating this type of input.
- lemon
-
Expects a grammar specification as understood by Richar Hipp's LEMON
parser generator and returns an abstract syntax tree for it.
- peg
-
Expects a grammar specification in the form of a parsing expression
grammar (PEG) and returns an abstract syntax tree for it.
- ser
-
Expect the serialized form of a parsing expression grammar as
generated by the package grammar::peg as input, converts it
into an equivalent abstract syntax tree and returns that.
- treeser
-
Expects the serialized form of a tree as generated by the package
struct::tree as input and returns it, after validation.
- Writer
-
- hb
-
Expects an abstract syntax tree for a parsing expression grammar as
input and writes it out in the form of a so-called
half-baked PEG container.
- identity
-
Takes any input and writes it as is.
- mecpu
-
Expects symbolic assembler code for the MatchEngine CPU (See the
package grammar::me::cpu and relatives) and writes it out as
Tcl code for a parser.
- me
-
Expects an abstract syntax tree for a parsing expression grammar as
input and writes it out as Tcl code for the MatchEngine (See the
package grammar::me and relatives) which parses input in
that grammar.
- null
-
Takes any input and writes nothing. The logical equivalent of
/dev/null.
- peg
-
Expects an abstract syntax tree for a parsing expression grammar as
input and writes it out in the form of a canonical PEG which can be
read by the reader plugin peg.
- ser
-
Expects an abstract syntax tree for a parsing expression grammar as
input and writes it out as a serialized PEG container which can be
read by the reader plugin ser.
- tpc
-
Expects an abstract syntax tree for a parsing expression grammar as
input and writes it out as Tcl code initializing a PEG container as
provided by the package grammar::peg.
- tree
-
Takes any serialized tree (per package struct::tree) as
input and writes it out in a generic indented format.
- Transformation
-
- mecpu
-
Takes an abstract syntax tree for a parsing expression grammer as
input, generates symbolic assembler code for the MatchEngine CPU, and
returns that as its result (See the package grammar::me::cpu
and relatives).
- reachable
-
Takes an abstract syntax tree for a parsing expression grammer as
input, performs a reachability analysis, and returns the modified and
annotated tree.
- realizable
-
Takes an abstract syntax tree for a parsing expression grammer as
input, performs an analysis of realizability, and returns the modified
and annotated tree.
The plugin manager currently checks the plugins for only one feature,
timeable. A plugin supporting this feature is assumed to be
able to collect timing statistics on request.
This document, will undoubtedly contain bugs and other problems.
Please report such in the category
page of the
http://sourceforge.net/tracker/?group_id=12883.
Please also report any ideas for enhancements you may have.
page, parser generator, text processing