37 lines
2.1 KiB
Text
37 lines
2.1 KiB
Text
This module provides a simple way to extend the Math::Symbolic parser with
|
|
arbitrary functions that return any valid Math::Symbolic tree. The return
|
|
value of the function call is inserted into the complete parse tree at the
|
|
point at which the function call is parsed. Familiarity with the
|
|
Math::Symbolic module will be assumed throughout the documentation.
|
|
|
|
This module is not object oriented. It does not export anything. You
|
|
should not call any subroutines directly nor should you modify any class
|
|
data directly. The complete interface is the call to use
|
|
Math::SymbolicX::ParserExtensionFactory and its arguments. The reason for
|
|
the long module name is that you should not have to call it multiple times
|
|
in your code because it modifies the parser for good. It is intended to be
|
|
a pain to type. :-)
|
|
|
|
The aim of the module is to allow for hooks into the parser without
|
|
modifying the parser yourself because that requires rather in-depth
|
|
knowledge of the module code. By specifying key => value pairs of function
|
|
names and function implementations (code references) as arguments to the
|
|
use() call of the module, this module extends the parser that is stored in
|
|
the $Math::Symbolic::Parser variable with the specified functions and
|
|
whenever "yourfunction(any argument string not containing an unescaped \)
|
|
)" occurs in the code, the subroutine reference is called with the
|
|
argument string as argument.
|
|
|
|
The subroutine is expected to return any Math::Symbolic tree. That means,
|
|
as of version 0.133, a Math::Symbolic::Operator, a
|
|
Math::Symbolic::Variable, or a Math::Symbolic::Constant object. The
|
|
returned object will be incorporated into the Math::Symbolic tree that
|
|
results from the parse at the exact position at which the custom function
|
|
call was parsed.
|
|
|
|
Please note that the usage of this module will be quite slow at compile
|
|
time because it has to regenerate the complete Math::Symbolic parser the
|
|
first time you use this module in your code. The run time performance
|
|
penalty should be low, however.
|
|
|
|
WWW: http://search.cpan.org/dist/Math-SymbolicX-ParserExtensionFactory/
|