Parser Class Reference

YCP parser A YCP parser read a characters stream and outputs a sequence of YCP values. Three properties of the YCP grammar are important:. More...

#include <Parser.h>

List of all members.

Public Member Functions
void	init ()
	Parser ()
	Parser (FILE *file, const char *filename=0)
	Parser (const char *buf)
	Parser (int fd, const char *filename=0)
	~Parser ()
YCodePtr	parse (SymbolTable *gTable=0, SymbolTable *lTable=0)
Scanner *	scanner ()
void	setScanner (Scanner *)
bool	atEOF ()
void	setInput (FILE *file, const char *filename=0)
void	setInput (const char *buf)
void	setInput (int fd, const char *filename=0)
void	setBuffered ()
void	setDepends ()
bool	depends () const
Public Attributes
YCodePtr	m_result
int	m_lineno
int	m_loop_count
int	m_parser_errors
blockstack_t *	m_block_stack
switchstack_t *	m_switch_stack
scannerstack_t *	m_scanner_stack
YBlockPtr	m_current_block
int	m_blockstack_depth
Private Attributes
Scanner *	m_scanner
bool	m_buffered
bool	m_depends
bool	m_at_eof

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Detailed Description

YCP parser A YCP parser read a characters stream and outputs a sequence of YCP values. Three properties of the YCP grammar are important:.

1. The syntactical representation of a YCP value uniquely defines its type.

2. The interpretation of the syntactical representation of a YCP value is not dependend on the leading context.

3. The interpretation of the syntactical representation of a YCP value is not dependend on the trailing context other than one trailing white space.

Property 1 allows you to call the parser without the specification, which type of value you expect. This allows a YCP protocol block to be of any YCP value.

Property 2 allows the parser class to be free of variables that must be kept between to parses.

Property 3 is especially important, because it allows the parser to determine the end of a value without having to look ahead more that one character.

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Constructor & Destructor Documentation

Parser::Parser

(

)

Creates a new YCP parser. Afterwards you must set an input source with a call to setInput

Parser::Parser	(	FILE *	file,
		const char *	filename = 0
	)

Creates a new YCP parser

Parameters:

filename

If you have the name of the file you parse available, pass it here in order to get nice error location messages in case of a parse error.

Parser::Parser

(

const char *

buf

)

Creates a new YCP parser

Parser::Parser	(	int	fd,
		const char *	filename = 0
	)

Creates a new YCP parser

Parameters:

filename

If you have the name of the file you parse available, pass it here in order to get nice error location messages in case of a parse error.

Parser::~Parser

(

)

Cleans up.

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Member Function Documentation

void Parser::init

(

)

Initialize the internal state of the parser.

YCodePtr Parser::parse	(	SymbolTable *	gTable = 0,
		SymbolTable *	lTable = 0
	)

Reads in as many bytes from the input stream as are neccessary to parse a YCP file.

Returns:

the parsed value. Returns 0, if no value could be parsed (due to a parse error or the end of the input stream). The value must be deleted after use.

If gTable and lTable are set, they're used instead of local ones. This is used for include files using the symbol tables of the including block. see: Scanner::initTables()

Scanner * Parser::scanner

(

)

Accesses the scanner

void Parser::setScanner

(

Scanner *

)

Sets the scanner. For scannerstack use, this should be encapsulated better.

bool Parser::atEOF

(

)

report EOF state. If parse() returns 0 the caller should check atEOF() in order to distinguish between a syntax error and end-of-file.

void Parser::setInput	(	FILE *	file,
		const char *	filename = 0
	)

use file for further parsing.

Parameters:

filename

If you have the name of the file you parse available, pass it here in order to get nice error location messages in case of a parse error.

void Parser::setInput

(

const char *

buf

)

use buf for further parsing

void Parser::setInput	(	int	fd,
		const char *	filename = 0
	)

Parse a value from a file descriptor

Parameters:

filename

If you have the name of the file you parse available, pass it here in order to get nice error location messages in case of a parse error.

void Parser::setBuffered

(

)

Makes the scanner use buffering, i.e. read more than one character at once.

void Parser::setDepends

(

)

Just output dependencies.

bool Parser::depends

(

)

const

Only dependencies ?

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Member Data Documentation

Scanner* Parser::m_scanner [private]

This is where the parser gets its input from.

bool Parser::m_buffered [private]

Is true, if the input can be buffered, i.e. more than one character may be read at once in order to gain performance.

bool Parser::m_depends [private]

Is true, if just imported modules and included files are to be checked (make depends)

bool Parser::m_at_eof [private]

If true, the scanner reached EOF.

YCodePtr Parser::m_result

Copied from struct parserret Does not need to be deleted by us

int Parser::m_lineno

Copied from struct parserret

int Parser::m_loop_count

Loop nesting level. Detects break outside a loop. Was a static variable in parser.yy

int Parser::m_parser_errors

Errors during one parse. Was a static variable in parser.yy

blockstack_t* Parser::m_block_stack

Stack of parsed blocks

switchstack_t* Parser::m_switch_stack

Stack of parsed switches

scannerstack_t* Parser::m_scanner_stack

Scanners used for include parsing

YBlockPtr Parser::m_current_block

pointer to the currently parsed block

int Parser::m_blockstack_depth

integer number for the depth of the current block

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

• Parser.h
• Parser.cc

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