Struct Bits 

pub struct Bits { /* private fields */ }

The Bits structure stores the encoded data for a QR code.

Implementations

impl Bits

pub const fn new(version: Version) -> Bits

Constructs a new, empty bits structure.

pub fn push_number_checked( &mut self, n: usize, number: usize, ) -> Result<(), QrError>

Pushes an N-bit big-endian integer to the end of the bits, and check that the number does not overflow the bits.

Returns Err(QrError::DataTooLong) on overflow.

pub fn reserve(&mut self, n: usize)

Reserves n extra bits of space for pushing.

pub fn into_bytes(self) -> Vec<u8>

Convert the bits into a byte vector.

pub fn len(&self) -> usize

Total number of bits currently pushed.

pub fn is_empty(&self) -> bool

Whether there are any bits pushed.

pub fn max_len(&self, ec_level: EcLevel) -> Result<usize, QrError>

The maximum number of bits allowed by the provided QR code version and error correction level.

Errors

Returns Err(QrError::InvalidVersion) if it is not valid to use the ec_level for the given version (e.g. Version::Micro(1) with EcLevel::H).

pub fn version(&self) -> Version

Version of the QR code.

impl Bits

pub fn push_mode_indicator(&mut self, mode: ExtendedMode) -> Result<(), QrError>

Push the mode indicator to the end of the bits.

Errors

If the mode is not supported in the provided version, this method returns Err(QrError::UnsupportedCharacterSet).

impl Bits

pub fn push_eci_designator( &mut self, eci_designator: u32, ) -> Result<(), QrError>

Push an ECI (Extended Channel Interpretation) designator to the bits.

An ECI designator is a 6-digit number to specify the character set of the following binary data. After calling this method, one could call .push_byte_data() or similar methods to insert the actual data, e.g.

#![allow(unused_must_use)]

use qrcode_core::bits::Bits;
use qrcode_core::types::Version;

let mut bits = Bits::new(Version::Normal(1));
bits.push_eci_designator(9); // 9 = ISO-8859-7 (Greek).
bits.push_byte_data(b"\xa1\xa2\xa3\xa4\xa5"); // ΑΒΓΔΕ

The full list of ECI designator values can be found from http://strokescribe.com/en/ECI.html. Some example values are:

ECI #	Character set
3	ISO-8859-1 (Western European)
20	Shift JIS (Japanese)
23	Windows 1252 (Latin 1) (Western European)
25	UTF-16 Big Endian
26	UTF-8
28	Big 5 (Traditional Chinese)
29	GB-18030 (Simplified Chinese)
30	EUC-KR (Korean)

Errors

If the QR code version does not support ECI, this method will return Err(QrError::UnsupportedCharacterSet).

If the designator is outside the expected range, this method will return Err(QrError::InvalidECIDesignator).

impl Bits

pub fn push_numeric_data(&mut self, data: &[u8]) -> Result<(), QrError>

Encodes a numeric string to the bits.

The data should only contain the characters 0 to 9.

Errors

Returns Err(QrError::DataTooLong) on overflow.

impl Bits

pub fn push_alphanumeric_data(&mut self, data: &[u8]) -> Result<(), QrError>

Encodes an alphanumeric string to the bits.

The data should only contain the characters A to Z (excluding lowercase), 0 to 9, space, $, %, *, +, -, ., / or :.

Errors

Returns Err(QrError::DataTooLong) on overflow.

impl Bits

pub fn push_byte_data(&mut self, data: &[u8]) -> Result<(), QrError>

Encodes 8-bit byte data to the bits.

Errors

Returns Err(QrError::DataTooLong) on overflow.

impl Bits

pub fn push_kanji_data(&mut self, data: &[u8]) -> Result<(), QrError>

Encodes Shift JIS double-byte data to the bits.

Errors

Returns Err(QrError::DataTooLong) on overflow.

Returns Err(QrError::InvalidCharacter) if the data is not Shift JIS double-byte data (e.g. if the length of data is not an even number).

impl Bits

pub fn push_mode_data<M>(&mut self, data: &[u8]) -> Result<(), QrError>

where M: EncodingMode,

Encodes data with a type-level QR encoding mode.

This is the type-safe counterpart to calling one of push_numeric_data, push_alphanumeric_data, push_byte_data, or push_kanji_data directly.

Errors

Returns QrError::InvalidCharacter when data is not valid for M. Returns the same length or version errors as the mode-specific push method after validation succeeds.

impl Bits

pub fn push_fnc1_first_position(&mut self) -> Result<(), QrError>

Encodes an indicator that the following data are formatted according to the UCC/EAN Application Identifiers standard.

#![allow(unused_must_use)]

use qrcode_core::bits::Bits;
use qrcode_core::types::Version;

let mut bits = Bits::new(Version::Normal(1));
bits.push_fnc1_first_position();
bits.push_numeric_data(b"01049123451234591597033130128");
bits.push_alphanumeric_data(b"%10ABC123");

In QR code, the character % is used as the data field separator (0x1D).

Errors

If the mode is not supported in the provided version, this method returns Err(QrError::UnsupportedCharacterSet).

pub fn push_fnc1_second_position( &mut self, application_indicator: u8, ) -> Result<(), QrError>

Encodes an indicator that the following data are formatted in accordance with specific industry or application specifications previously agreed with AIM International.

#![allow(unused_must_use)]

use qrcode_core::bits::Bits;
use qrcode_core::types::Version;

let mut bits = Bits::new(Version::Normal(1));
bits.push_fnc1_second_position(37);
bits.push_alphanumeric_data(b"AA1234BBB112");
bits.push_byte_data(b"text text text text\r");

If the application indicator is a single Latin alphabet (a–z / A–Z), please pass in its ASCII value + 100:

bits.push_fnc1_second_position(b'A' + 100);

Errors

If the mode is not supported in the provided version, this method returns Err(QrError::UnsupportedCharacterSet).

impl Bits

pub fn push_structured_append_header( &mut self, position: u8, total: u8, parity: u8, ) -> Result<(), QrError>

Pushes a Structured Append header (ISO/IEC 18004 §7.4) to the front of the bit stream.

Structured Append splits one logical message across 2..=16 QR symbols. Every symbol in the sequence carries this 20-bit header as the very first thing in its bit stream, before the data mode indicator:

• 4-bit mode indicator 0011,
• an 8-bit symbol-sequence indicator whose high nibble is this symbol’s position (1-based, 1..=total) and whose low nibble is the total symbol count (2..=16),
• an 8-bit parity byte (the XOR of every byte of the original, un-split message — identical in every symbol).

A position/total of 16 wraps to nibble 0 (the only encoding of 16 in four bits); a spec-aware reader reads nibble 0 as 16.

Structured Append is not valid for Micro QR; this method returns Err(QrError::UnsupportedCharacterSet) for a Micro QR version.

Errors

Returns QrError::UnsupportedCharacterSet on a Micro QR version, and QrError::InvalidStructuredAppend if total is not 2..=16 or position is not 1..=total.

use qrcode_core::bits::Bits;
use qrcode_core::types::Version;

let mut bits = Bits::new(Version::Normal(1));
bits.push_structured_append_header(1, 3, 0x5a);
// First symbol of a 3-symbol sequence; parity 0x5a.

impl Bits

pub fn push_terminator(&mut self, ec_level: EcLevel) -> Result<(), QrError>

Pushes the ending bits to indicate no more data.

Errors

Returns Err(QrError::DataTooLong) on overflow.

Returns Err(QrError::InvalidVersion) if it is not valid to use the ec_level for the given version (e.g. Version::Micro(1) with EcLevel::H).

impl Bits

pub fn push_segments<I>( &mut self, data: &[u8], segments_iter: I, ) -> Result<(), QrError>

where I: Iterator<Item = Segment>,

Push a segmented data to the bits, and then terminate it.

Errors

Returns Err(QrError::DataTooLong) on overflow.

Returns Err(QrError::InvalidData) if the segment refers to incorrectly encoded byte sequences.

pub fn push_optimal_data(&mut self, data: &[u8]) -> Result<(), QrError>

Pushes the data the bits, using the optimal encoding.

Errors

Returns Err(QrError::DataTooLong) on overflow.