bertini::node::DecodingCursor Class Reference

A read position over one canonical-encoding text, with the small lexical helpers the grammar needs (literals, words, netstrings, numbers). More...

#include <canonical_decoding.hpp>

Public Member Functions
	DecodingCursor (std::string const &text)
	Start reading text from its first byte.
bool	AtEnd () const
	Whether every byte has been consumed.
std::size_t	Offset () const
	The byte offset of the next unread character.
char	Peek () const
	The next unread character (throws at end of text).
void	Expect (char c)
	Consume exactly the character c, or throw.
void	Expect (std::string_view lit)
	Consume exactly the literal lit, or throw.
bool	TryConsume (char c)
	Consume c if it is next; report whether it was.
void	SkipWhitespace ()
	Skip any run of spaces and newlines.
std::string	ReadWord ()
	Read a maximal run of characters that are not whitespace or a parenthesis.
std::string	ReadNetstring ()
	Read a netstring name: <byte-length>:<bytes>.
unsigned long long	ReadUnsigned ()
	Read a non-negative decimal integer.
long long	ReadInt ()
	Read a decimal integer with an optional sign.
void	Fail (std::string const &what) const
	Throw std::runtime_error describing what at the current position.

Detailed Description

A read position over one canonical-encoding text, with the small lexical helpers the grammar needs (literals, words, netstrings, numbers).

The cursor does not own the text: keep the string alive for the cursor's lifetime. Every helper throws std::runtime_error with the byte offset and a snippet of the text when the input does not match, so a malformed or truncated encoding fails loudly at the first wrong byte instead of producing a wrong object.

Constructor & Destructor Documentation

DecodingCursor()

bertini::node::DecodingCursor::DecodingCursor ( std::string const & text )

inlineexplicit

Start reading text from its first byte.

Member Function Documentation

AtEnd()

bool bertini::node::DecodingCursor::AtEnd ( ) const

inline

Whether every byte has been consumed.

Expect() [1/2]

void bertini::node::DecodingCursor::Expect

(

char

c

)

Consume exactly the character c, or throw.

Expect() [2/2]

void bertini::node::DecodingCursor::Expect

(

std::string_view

lit

)

Consume exactly the literal lit, or throw.

Fail()

void bertini::node::DecodingCursor::Fail

(

std::string const &

what

)

const

Throw std::runtime_error describing what at the current position.

Offset()

std::size_t bertini::node::DecodingCursor::Offset ( ) const

inline

The byte offset of the next unread character.

Peek()

char bertini::node::DecodingCursor::Peek

(

)

const

The next unread character (throws at end of text).

ReadInt()

long long bertini::node::DecodingCursor::ReadInt

(

)

Read a decimal integer with an optional sign.

ReadNetstring()

std::string bertini::node::DecodingCursor::ReadNetstring

(

)

Read a netstring name: <byte-length>:<bytes>.

ReadUnsigned()

unsigned long long bertini::node::DecodingCursor::ReadUnsigned

(

)

Read a non-negative decimal integer.

ReadWord()

std::string bertini::node::DecodingCursor::ReadWord

(

)

Read a maximal run of characters that are not whitespace or a parenthesis.

SkipWhitespace()

void bertini::node::DecodingCursor::SkipWhitespace

(

)

Skip any run of spaces and newlines.

TryConsume()

bool bertini::node::DecodingCursor::TryConsume

(

char

c

)

Consume c if it is next; report whether it was.