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[call [arg objectName] [method destroy]]
This method destroys the parser instance, releasing all claimed memory
and other resources, and deleting the instance command.
[para]
The result of the command is the empty string.
[call [arg objectName] [method parse] [arg chan]]
This method runs the parser using the contents of [arg chan] as input
(starting at the current location in the channel), until parsing is
not possible anymore, either because parsing has completed, or run
into a syntax error.
[include channel_notes.inc]
[para]
Upon successful completion the command returns an abstract syntax tree
as its result.
This AST is in the form specified in section
[sectref {AST serialization format}].
As a plain nested Tcl-list it can then be processed with any Tcl
commands the user likes, doing transformations, semantic checks, etc.
To help in this the package [package pt::ast] provides a set of
convenience commands for validation of the tree's basic structure,
printing it for debugging, and walking it either from the bottom up,
or top down.
[para]
When encountering a syntax error the command will throw an error instead.
This error will be a 4-element Tcl-list, containing, in the order
listed below:
[list_begin enumerated]
[enum]
The string [const pt::rde] identifying it as parser runtime error.
[enum]
The location of the parse error, as character offset from the
beginning of the parsed input.
[enum]
The location of parse error, now as a 2-element list containing
line-number and column in the line.
[enum]
A set of atomic parsing expressions indicating encoding the characters
and/or nonterminal symbols the parser expected to see at the location
of the parse error, but did not get.
For the specification of atomic parsing expressions please see the
section [sectref {PE serialization format}].
[list_end]
[call [arg objectName] [method parset] [arg text]]
This method runs the parser using the string in [arg text] as input.
In all other ways it behaves like the method [method parse], shown
above.
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