Series
[Algebra]

Collaboration diagram for Series:

Files
file	krat_exp_parser.hh
	This file declares the parse() function.
Namespaces
namespace	vcsn::algebra::krat_exp_lexing
	Misc. declarations used for rational expression lexing.
Classes
struct	SeriesBase
	Structural element of series K<A*> from a free monoid A* to a semiring K. More...
struct	series_traits
	Meta information about series. More...
struct	dynamic_traits< algebra::SeriesBase< Self > >
class	MetaElement< algebra::SeriesBase< Self >, T >
	Services of every series. More...
class	KRatExpToken
	Schrödinger's token for rational expression lexing. More...
struct	Lexer
	Lexer class for the rational expression parser. More...
struct	Parser
	Parser class used in the parse() function. More...
Functions
template<typename S, typename T>
Element< S, T >	transpose (const algebra::SeriesBase< S > &s, const T &t)
	returns a fresh series that is the transposed of the argument.
template<typename S, typename T>
bool	is_support_in_alphabet (const Element< S, T > &s)
	Returns true if the support of the series is only composed of letters.
template<typename S1, typename S2, typename T1, typename T2>
void	extract_support (Element< S1, T1 > &, Element< S2, T2 > &)
	Make the first series be the support of the second.
template<class S, class T>
Element< S, T >	hadamard (const Element< S, T > &lhs, const Element< S, T > &rhs)
	Return the hadamard product of lhs and rhs.
template<class S, class T>
std::pair< bool, std::string >	parse (const std::string &from, Element< S, T > &exp, bool lex_trace=false, bool parse_trace=false)
	Parse a rational expression.

---

Function Documentation

std::pair< bool, std::string > parse	(	const std::string &	from,
		Element< S, T > &	exp,
		bool	lex_trace = false,
		bool	parse_trace = false
	)			[inline]

Parse a rational expression.

This functions parses any numerical rational expression. The grammar is:

     exp ::= '(' exp ')'
         |   exp '+' exp
         |   exp '.' exp
         |   exp exp
         |   exp '*'
         |   weight ' ' exp
         |   exp ' ' weight
         |   0
         |   1
         |   word
     

Priority for operators is, from the most important to the least important:

• * (star), to star a series.
• ' ' (space), to weight a series either on the right or on the left.
• . (dot), to concatenate two series.
• + (plus), to do the union of two series.

This function returns a pair which first element is a Boolean indicating whether an error occured or not. The second element is an error message when a parse error have been ecountered.

Note that this function requires exception support from the compiler.

Parameters:

	from	The rational expression, as a string.
	exp	The element to store the result in. Be sure its set is correct before calling parse.
	lex_trace	Enable lexer trace (for debuging purposes).
	parse_trace	Enable parser trace (for debuging purposes).

Author:

Yann Régis-Gianas <yann@lrde.epita.fr>, Thomas Claveirole <thomas@lrde.epita.fr>

Definition at line 690 of file krat_exp_parser.hxx.

References Parser::error(), Parser::error_msg(), Lexer::lex(), and Parser::parse().