hi::v1::lookahead_iterator< LookaheadCount, Iterator > Class Template Reference

#include <hikogui/lookahead_iterator.hpp>

Public Types
using	iterator = Iterator
using	value_type = iterator_type::value_type
using	reference = iterator_type::reference
using	const_reference = iterator_type::const_reference
using	pointer = iterator_type::pointer
using	const_pointer = iterator_type::const_pointer

Public Member Functions
constexpr	lookahead_iterator (lookahead_iterator const &) noexcept=delete
constexpr	lookahead_iterator (lookahead_iterator &&) noexcept=default
constexpr lookahead_iterator &	operator= (lookahead_iterator const &) noexcept=delete
constexpr lookahead_iterator &	operator= (lookahead_iterator &&) noexcept=default
constexpr	lookahead_iterator (forward_of< Iterator > auto &&it) noexcept
constexpr size_t	size () const noexcept
	The number of entries can be looked ahead.
constexpr bool	empty () const noexcept
	Check if the iterator is at end.
constexpr	operator bool () const noexcept
constexpr bool	operator== (std::default_sentinel_t const &) const noexcept
const_reference	operator[] (size_t i) const noexcept
	Get a reference to an item at or beyond the iterator.
const_reference	at (size_t i) const
	Get a reference to an item at or beyond the iterator.
std::optional< value_type >	next (size_t i=1) const noexcept
	Get a reference to an item at or beyond the iterator.
const_reference	operator* () const noexcept
	Get a reference to the value at the iterator.
const_pointer	operator-> () const noexcept
	Get a pointer to the value at the iterator.
lookahead_iterator &	operator++ () noexcept
	Increment the iterator.

Static Public Attributes
static constexpr size_t	max_size = LookaheadCount + 1

Detailed Description

template<size_t LookaheadCount, typename Iterator>
class hi::v1::lookahead_iterator< LookaheadCount, Iterator >

Lookahead iterator.

This iterator adapter takes a forward input iterator and adapts it so that you can look ahead beyond the current position of the iterator. This is useful when writing a parser.

Member Function Documentation

at()

template<size_t LookaheadCount, typename Iterator >

const_reference hi::v1::lookahead_iterator< LookaheadCount, Iterator >::at ( size_t i ) const

inline

Get a reference to an item at or beyond the iterator.

Parameters

i	Index to lookahead, 0 means the current iterator, larger than zero is lookahead.

Exceptions

std::out_of_range

when index beyond the lookahead buffer.

Returns

A reference to the item.

empty()

template<size_t LookaheadCount, typename Iterator >

constexpr bool hi::v1::lookahead_iterator< LookaheadCount, Iterator >::empty ( ) const

inlineconstexprnoexcept

Check if the iterator is at end.

Return values

true	Iterator at end.

next()

template<size_t LookaheadCount, typename Iterator >

std::optional< value_type > hi::v1::lookahead_iterator< LookaheadCount, Iterator >::next ( size_t i = 1 ) const

inlinenoexcept

Get a reference to an item at or beyond the iterator.

Parameters

i	Index to lookahead, 0 means the current iterator, larger than zero is lookahead.

Return values

std::nullopt

When the index points beyond the lookahead buffer.

Returns

A reference to the item.

operator*()

template<size_t LookaheadCount, typename Iterator >

const_reference hi::v1::lookahead_iterator< LookaheadCount, Iterator >::operator* ( ) const

inlinenoexcept

Get a reference to the value at the iterator.

operator++()

template<size_t LookaheadCount, typename Iterator >

lookahead_iterator & hi::v1::lookahead_iterator< LookaheadCount, Iterator >::operator++ ( )

inlinenoexcept

Increment the iterator.

operator->()

template<size_t LookaheadCount, typename Iterator >

const_pointer hi::v1::lookahead_iterator< LookaheadCount, Iterator >::operator-> ( ) const

inlinenoexcept

Get a pointer to the value at the iterator.

operator[]()

template<size_t LookaheadCount, typename Iterator >

const_reference hi::v1::lookahead_iterator< LookaheadCount, Iterator >::operator[] ( size_t i ) const

inlinenoexcept

Get a reference to an item at or beyond the iterator.

Parameters

i	Index to lookahead, 0 means the current iterator, larger than zero is lookahead.

Returns

A reference to the item.

size()

template<size_t LookaheadCount, typename Iterator >

constexpr size_t hi::v1::lookahead_iterator< LookaheadCount, Iterator >::size ( ) const

inlineconstexprnoexcept

The number of entries can be looked ahead.

Returns

Number of entries that can be looked ahead, including the current entry.

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

• hikogui/src/hikogui/lookahead_iterator.hpp