hi::v1::lookahead_iterator< LookaheadCount, It, ItEnd > Class Template Reference

#include <hikogui/parser/lookahead_iterator.hpp>

Data Structures
class	proxy

Public Types
using	value_type = std::iterator_traits<It>::value_type
using	reference = value_type const &
using	pointer = value_type const *
using	difference_type = std::ptrdiff_t
using	iterator_category = std::forward_iterator_tag

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 (It first, ItEnd last) 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 noexcept
constexpr reference	operator[] (size_t i) const noexcept
	Get a reference to an item at or beyond the iterator.
constexpr reference	at (size_t i) const
	Get a reference to an item at or beyond the iterator.
constexpr std::optional< value_type >	next (size_t i=1) const noexcept
	Get a reference to an item at or beyond the iterator.
constexpr reference	operator* () const noexcept
	Get a reference to the value at the iterator.
constexpr pointer	operator-> () const noexcept
	Get a pointer to the value at the iterator.
constexpr lookahead_iterator &	operator++ () noexcept
	Increment the iterator.
constexpr lookahead_iterator &	operator+= (size_t n) noexcept
constexpr proxy	operator++ (int) noexcept

Static Public Attributes
static constexpr size_t	max_size = LookaheadCount

Detailed Description

template<size_t LookaheadCount, typename It, std::sentinel_for< It > ItEnd = std::default_sentinel_t>
class hi::v1::lookahead_iterator< LookaheadCount, It, ItEnd >

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 It, std::sentinel_for< It > ItEnd = std::default_sentinel_t>

reference hi::v1::lookahead_iterator< LookaheadCount, It, ItEnd >::at ( size_t i ) const

inlinenodiscardconstexpr

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 It, std::sentinel_for< It > ItEnd = std::default_sentinel_t>

bool hi::v1::lookahead_iterator< LookaheadCount, It, ItEnd >::empty ( ) const

inlinenodiscardconstexprnoexcept

Check if the iterator is at end.

Return values

true	Iterator at end.

next()

template<size_t LookaheadCount, typename It, std::sentinel_for< It > ItEnd = std::default_sentinel_t>

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

inlinenodiscardconstexprnoexcept

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 It, std::sentinel_for< It > ItEnd = std::default_sentinel_t>

reference hi::v1::lookahead_iterator< LookaheadCount, It, ItEnd >::operator* ( ) const

inlineconstexprnoexcept

Get a reference to the value at the iterator.

operator++()

template<size_t LookaheadCount, typename It, std::sentinel_for< It > ItEnd = std::default_sentinel_t>

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

inlineconstexprnoexcept

Increment the iterator.

operator->()

template<size_t LookaheadCount, typename It, std::sentinel_for< It > ItEnd = std::default_sentinel_t>

pointer hi::v1::lookahead_iterator< LookaheadCount, It, ItEnd >::operator-> ( ) const

inlineconstexprnoexcept

Get a pointer to the value at the iterator.

operator[]()

template<size_t LookaheadCount, typename It, std::sentinel_for< It > ItEnd = std::default_sentinel_t>

reference hi::v1::lookahead_iterator< LookaheadCount, It, ItEnd >::operator[] ( size_t i ) const

inlinenodiscardconstexprnoexcept

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 It, std::sentinel_for< It > ItEnd = std::default_sentinel_t>

size_t hi::v1::lookahead_iterator< LookaheadCount, It, ItEnd >::size ( ) const

inlinenodiscardconstexprnoexcept

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/parser/lookahead_iterator.hpp