Lr0Item Struct Reference

Represents an LR(0) item used in LR automata construction. More...

#include <lr0_item.hpp>

Public Member Functions
	Lr0Item (std::string antecedent, std::vector< std::string > consequent, std::string epsilon, std::string eol)
	Constructs an LR(0) item with the dot at position 0.
	Lr0Item (std::string antecedent, std::vector< std::string > consequent, unsigned int dot, std::string epsilon, std::string eol)
	Constructs an LR(0) item with a custom dot position.
std::string	NextToDot () const
	Returns the symbol immediately after the dot, or empty if the dot is at the end.
void	PrintItem () const
	Prints the LR(0) item to the standard output in a human-readable format.
std::string	ToString () const
	Converts the item to a string representation, including the dot position.
void	AdvanceDot ()
	Advances the dot one position to the right.
bool	IsComplete () const
	Checks whether the dot has reached the end of the production.
bool	operator== (const Lr0Item &other) const
	Equality operator for comparing two LR(0) items.

Public Attributes
std::string	antecedent_
	The non-terminal on the left-hand side of the production.
std::vector< std::string >	consequent_
	The sequence of symbols on the right-hand side of the production.
std::string	epsilon_
	The symbol representing the empty string (ε).
std::string	eol_
	The symbol representing end-of-line or end-of-input ($).
unsigned int	dot_ = 0
	The position of the dot (·) in the production.

Detailed Description

Represents an LR(0) item used in LR automata construction.

An LR(0) item has a production of the form A → α·β, where the dot indicates the current parsing position. This structure tracks the antecedent (left-hand side), consequent (right-hand side), the dot position, and special symbols like EPSILON and end-of-line ($).

Constructor & Destructor Documentation

Lr0Item() [1/2]

Lr0Item::Lr0Item	(	std::string	antecedent,
		std::vector< std::string >	consequent,
		std::string	epsilon,
		std::string	eol )

Constructs an LR(0) item with the dot at position 0.

Parameters

antecedent	The left-hand side non-terminal.
consequent	The right-hand side of the production.
epsilon	The EPSILON symbol.
eol	The end-of-line symbol.

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Lr0Item() [2/2]

Lr0Item::Lr0Item	(	std::string	antecedent,
		std::vector< std::string >	consequent,
		unsigned int	dot,
		std::string	epsilon,
		std::string	eol )

Constructs an LR(0) item with a custom dot position.

Parameters

antecedent	The left-hand side non-terminal.
consequent	The right-hand side of the production.
dot	The position of the dot.
epsilon	The EPSILON symbol.
eol	The end-of-line symbol.

Member Function Documentation

AdvanceDot()

void Lr0Item::AdvanceDot

(

)

Advances the dot one position to the right.

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IsComplete()

bool Lr0Item::IsComplete

(

)

const

Checks whether the dot has reached the end of the production.

Returns

true if the item is complete; false otherwise.

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NextToDot()

std::string Lr0Item::NextToDot

(

)

const

Returns the symbol immediately after the dot, or empty if the dot is at the end.

Returns

The symbol after the dot, or an empty string.

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operator==()

bool Lr0Item::operator==

(

const Lr0Item &

other

)

const

Equality operator for comparing two LR(0) items.

Parameters

other

The item to compare with.

Returns

true if both items are equal; false otherwise.

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PrintItem()

void Lr0Item::PrintItem

(

)

const

Prints the LR(0) item to the standard output in a human-readable format.

ToString()

std::string Lr0Item::ToString

(

)

const

Converts the item to a string representation, including the dot position.

Returns

A string representation of the item.

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Member Data Documentation

antecedent_

std::string Lr0Item::antecedent_

The non-terminal on the left-hand side of the production.

consequent_

std::vector<std::string> Lr0Item::consequent_

The sequence of symbols on the right-hand side of the production.

dot_

unsigned int Lr0Item::dot_ = 0

The position of the dot (·) in the production.

eol_

std::string Lr0Item::eol_

The symbol representing end-of-line or end-of-input ($).

epsilon_

std::string Lr0Item::epsilon_

The symbol representing the empty string (ε).

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

• backend/lr0_item.hpp
• backend/lr0_item.cpp