teditor::parser::NFA Struct Reference

Ken-Thompson NFA as described here: https://swtch.com/~rsc/regexp/regexp1.html but adjusted to work with teditor environment. More...

#include <nfa.h>

Public Member Functions
	NFA (const std::string &reg)
	ctor with adding a regex for the NFA More...
size_t	find (const std::string &str, size_t start=0, size_t end=0)
	String match function. More...
size_t	findAny (const std::string &str, size_t &matchStartPos, size_t start=0, size_t end=0)
	Tries for regex match starting from anywhere in the string. More...
	~NFA ()
bool	isMatch (bool lastStateRemaining=false) const
	checks if we have reached match state, indicating a regex match More...
bool	areActiveStatesEmpty () const
	Tells if after the current step() whether there are any active states still remaining. So, this can be used to prematurely stop the regex search in the string. More...
const Point &	getMatchPos () const
	After the search has finished, use this to know the latest position of the match of the regex in the input string. More...
bool	step (char c, const Point &pos)
	Step through the NFA state using the current char. More...
void	reset ()
	Reset all the variables used during regex search. This needs to be called once before beginning of every search. More...

Static Public Attributes
static const size_t	NoMatch = std::string::npos

Detailed Description

Ken-Thompson NFA as described here: https://swtch.com/~rsc/regexp/regexp1.html but adjusted to work with teditor environment.

Note

the current design is not thread-safe! Meaning, the same NFA object cannot be used by multiple threads at the same. It will cause corruption of data

Constructor & Destructor Documentation

NFA()

teditor::parser::NFA::NFA

(

const std::string &

reg

)

ctor with adding a regex for the NFA

Parameters

reg

regex

~NFA()

teditor::parser::NFA::~NFA ( )

inline

Member Function Documentation

find()

size_t teditor::parser::NFA::find	(	const std::string &	str,
		size_t	start = 0,
		size_t	end = 0
	)

String match function.

Parameters

str	the input string
start	location from where to start searching
end	location (minus 1) till where to search

Returns

the location of the longest match, else returns NFA::NoMatch

findAny()

size_t teditor::parser::NFA::findAny	(	const std::string &	str,
		size_t &	matchStartPos,
		size_t	start = 0,
		size_t	end = 0
	)

Tries for regex match starting from anywhere in the string.

Parameters

str	the input string
matchStartPos	will contain the starting location of the longest match, if found, else, NFA::NoMatch
start	location from where to start searching
end	location (minus 1) till where to search

Returns

the location of the longest match, else returns NFA::NoMatch

Member Data Documentation

NoMatch

const size_t teditor::parser::NFA::NoMatch = std::string::npos

static

represents case when regex didn't match anything

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

• nfa.h
• nfa.cpp