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