strus::ProgramLexer Class Reference

Class for a lexer used for implementing domain specific languages of strus. More...

#include <programLexer.hpp>

Public Types
enum	Option { KeepStringEscaping =1 }

Public Member Functions
	ProgramLexer (const char *src, const char *eolncomment_, const char **tokens, const char **errtokens, ErrorBufferInterface *errhnd_)
	Constructor. More...
	~ProgramLexer ()
const ProgramLexem &	next ()
	Get the next lexem. More...
const ProgramLexem &	current ()
	Get the current lexem. More...
const ProgramLexem &	rescanCurrent ()
	Rescan the current lexem (with different options) More...
bool	consumeToken (int tokid)
	Skip to next and return true if the current lexem is a token with a defined id. More...
bool	setOption (Option opt_, bool value)
	Switch lexer option on/off. More...
int	lineno () const
	Get the current line number. More...
const char *	pos () const
	Get the current source pointer. More...
std::size_t	len () const
	Get the rest length to parse. More...
bool	skipto (char const *pos)
	Skip to a defined position is the parsed source and scan the next token. More...
const char *	nextpos ()
	Get the start of the next token. More...
const char *	currentpos ()
	Get the start of the current token. More...
std::string	currentLocationString (int posincr, int size, const char *marker) const
	Get an excerpt of the current source location starting from a position with a marker inserted. More...

Detailed Description

Class for a lexer used for implementing domain specific languages of strus.

Member Enumeration Documentation

enum strus::ProgramLexer::Option

Enumerator
KeepStringEscaping

Constructor & Destructor Documentation

strus::ProgramLexer::ProgramLexer	(	const char *	src,
		const char *	eolncomment_,
		const char **	tokens,
		const char **	errtokens,
		ErrorBufferInterface *	errhnd_
	)

Constructor.

Parameters

[in]	src	pointer to source to parse
[in]	eolncomment_	operator used for comments (end of line comments)
[in]	errtokens	illegal lexems defined as regular expressions (leading to a syntax error)
[in]	tokens	lexems defined as regular expressions with the position in the array as associated id
[in]	errhnd_	error buffer interface to use for reporting errors

strus::ProgramLexer::~ProgramLexer

(

)

Member Function Documentation

bool strus::ProgramLexer::consumeToken ( int  tokid )

inline

Skip to next and return true if the current lexem is a token with a defined id.

const ProgramLexem& strus::ProgramLexer::current ( )

inline

Get the current lexem.

std::string strus::ProgramLexer::currentLocationString	(	int	posincr,
		int	size,
		const char *	marker
	)		const

Get an excerpt of the current source location starting from a position with a marker inserted.

Parameters

[in]	posincr	increment of the current position to show
[in]	marker	marker to insert in the result at the current position
[in]	size	size of excerpt to show

const char* strus::ProgramLexer::currentpos

(

)

Get the start of the current token.

Returns

the position of the current token or NULL, if an error occurred or if we got to the end of source

std::size_t strus::ProgramLexer::len ( ) const

inline

Get the rest length to parse.

int strus::ProgramLexer::lineno

(

)

const

Get the current line number.

Remarks

expensive operation, if scans the source every time it is called, because it is thought to be used only for error messages

const ProgramLexem& strus::ProgramLexer::next

(

)

Get the next lexem.

const char* strus::ProgramLexer::nextpos

(

)

Get the start of the next token.

Returns

the position of the next token or NULL, if an error occurred or if we got to the end of source

const char* strus::ProgramLexer::pos ( ) const

inline

Get the current source pointer.

const ProgramLexem& strus::ProgramLexer::rescanCurrent

(

)

Rescan the current lexem (with different options)

bool strus::ProgramLexer::setOption	(	Option	opt_,
		bool	value
	)

Switch lexer option on/off.

Parameters

[in]	opt	option identifier
[in]	value	true=on, false=off

Returns

previous option value

bool strus::ProgramLexer::skipto

(

char const *

pos

)

Skip to a defined position is the parsed source and scan the next token.

Parameters

[in]

pos

pointer to position to set scanner to for restart scanning

Remarks

pos must be inside of the parsed source

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The documentation for this class was generated from the following file:

• /home/patrick/Projects/github/strusBase/include/strus/base/programLexer.hpp