lxr Class Reference
[Lexical analysis]

#include <lxr.hh>

List of all members.

Public Types
enum	select_type { kChar, kGroup, kDefault, kEOF }
enum	flag_bits { kUnget, kNoSave, kReturn }
typedef int	state_type
typedef char	char_type
typedef int	token_type
typedef std::vector< transition >	trans_list
Public Member Functions
	lxr (int N)
void	check (bool warn) const
void	dump (void) const
const transition &	find (int state, char c) const
token_type	token (std::istream &in, std::string &tkn) const
int	push_state (void)
void	addTransition (int state, select_type sel, char_type sel_id, int flags, int next)
void	setState0 (int state)
void	setTable (const Translate< char > &table)
Classes
class	transition

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Detailed Description

This class takes in a stream of characters and uses them to build an output string. Each character read in is optionally stored into the output string and is used to calculate a new state. When the end of a token is detected, the analysis method (token()) returns the token string and ID as specified by the state tables. Lexographic analysis is based on a state table and a character translation table provided by the user. brief Table driven state machine lexographic analysis.

Author:

J. Zweizig

Version:

1.1; Last modified March 3, 2008

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Member Typedef Documentation

typedef int lxr::state_type

State data type

typedef char lxr::char_type

Character data type

typedef int lxr::token_type

Token data type

typedef std::vector<transition> lxr::trans_list

Define transition list data type.

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Member Enumeration Documentation

enum lxr::select_type

Enumerate selection type

enum lxr::flag_bits

Enumerate flag bits.

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Constructor & Destructor Documentation

lxr::lxr

(

int

N

)

Construct a lxr object. Allocate tables for the specified number of states.

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Member Function Documentation

void lxr::check

(

bool

warn

)

const

Check the state table for undefined states and for ambiguously defined transitions. If an undefined state or ambiguous transition is found, it is reported and an invlid state table exception is thrown. If the warn argument is true, check will also report missing EOF and Default values.

void lxr::dump

(

void

)

const

Dump out the state transition table.

const transition& lxr::find	(	int	state,
		char	c
	)			const

Find the state transition entry

token_type lxr::token	(	std::istream &	in,
		std::string &	tkn
	)			const

Get the next token. The token type is return as the function value, and the token string is returned to the second argument value.

int lxr::push_state

(

void

)

Allocate a new state. No transition entries are added.

void lxr::addTransition	(	int	state,
		select_type	sel,
		char_type	sel_id,
		int	flags,
		int	next
	)

Add a transition entry to the table for the specified state.

void lxr::setState0

(

int

state

)

Set the initial state number. By default, state 0 is the initial state.

void lxr::setTable

(

const Translate< char > &

table

)

Set a translation table that defines the group ID for each character.

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

• lxr/lxr.hh

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