UnmatchedKeyParentheses,

MissingModuloSign,

UnsupportedFormatChar(CodePoint),

IncompleteFormat,

IntTooBig,

// Unimplemented,

fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {

use CFormatErrorType::*;

match self.typ {

UnmatchedKeyParentheses => write!(f, "incomplete format key"),

IncompleteFormat => write!(f, "incomplete format"),

UnsupportedFormatChar(c) => write!(

f,

"unsupported format character '{}' ({:#x}) at index {}",

c,

c.to_u32(),

self.index

),

IntTooBig => write!(f, "width/precision too big"),

_ => write!(f, "unexpected error parsing format string"),

}

}

DecimalD = b'd',

DecimalI = b'i',

DecimalU = b'u',

Octal = b'o',

HexLower = b'x',

HexUpper = b'X',

ExponentLower = b'e',

ExponentUpper = b'E',

PointDecimalLower = b'f',

PointDecimalUpper = b'F',

GeneralLower = b'g',

GeneralUpper = b'G',

const fn case(self) -> Case {

use CFloatType::*;

match self {

ExponentLower | PointDecimalLower | GeneralLower => Case::Lower,

ExponentUpper | PointDecimalUpper | GeneralUpper => Case::Upper,

}

}

Number(CNumberType),

Float(CFloatType),

Character(CCharacterType),

String(CFormatConversion),

pub const fn to_char(self) -> char {

match self {

Self::Number(x) => x as u8 as char,

Self::Float(x) => x as u8 as char,

Self::Character(x) => x as u8 as char,

Self::String(x) => x as u8 as char,

}

}

fn from(quantity: CFormatQuantity) -> Self {

Self::Quantity(quantity)

}

#[inline]

pub const fn sign_string(&self) -> &'static str {

if self.contains(Self::SIGN_CHAR) {

"+"

} else if self.contains(Self::BLANK_SIGN) {

" "

} else {

""

}

}

Extend<Self::Char> + Default + FromIterator<Self::Char> + From<String>

type Char: FormatChar;

fn chars(&self) -> impl Iterator<Item = Self::Char>;

fn len(&self) -> usize;

fn is_empty(&self) -> bool {

self.len() == 0

}

fn concat(self, other: Self) -> Self;

type Char = char;

fn chars(&self) -> impl Iterator<Item = Self::Char> {

(**self).chars()

}

fn len(&self) -> usize {

self.len()

}

fn concat(mut self, other: Self) -> Self {

self.extend([other]);

self

}

type Char = CodePoint;

fn chars(&self) -> impl Iterator<Item = Self::Char> {

self.code_points()

}

fn len(&self) -> usize {

(**self).len()

}

fn concat(mut self, other: Self) -> Self {

self.extend([other]);

self

}

fn to_char_lossy(self) -> char {

self.to_char_lossy()

}

fn eq_char(self, c: char) -> bool {

self == c

}

type Char = u8;

fn chars(&self) -> impl Iterator<Item = Self::Char> {

self.iter().copied()

}

fn len(&self) -> usize {

self.len()

}

fn concat(mut self, other: Self) -> Self {

self.extend(other);

self

}

pub flags: CConversionFlags,

pub min_field_width: Option<CFormatQuantity>,

pub precision: Option<CFormatPrecision>,

pub format_type: CFormatType,

// chars_consumed: usize,

type Err = ParsingError;

fn from_str(text: &str) -> Result<Self, Self::Err> {

text.parse::<CFormatSpecKeyed<String>>()

.map(|CFormatSpecKeyed { mapping_key, spec }| {

assert!(mapping_key.is_none());

spec

})

}

type Err = ParsingError;

fn from_str(text: &str) -> Result<Self, Self::Err> {

let mut chars = text.chars().enumerate().peekable();

if chars.next().map(|x| x.1) != Some('%') {

return Err((CFormatErrorType::MissingModuloSign, 1));

}

Self::parse(&mut chars)

}

pub fn parse<I>(iter: &mut ParseIter<I>) -> Result<Self, ParsingError>

where

I: Iterator<Item = T::Char>,

{

let mapping_key = parse_spec_mapping_key(iter)?;

let flags = parse_flags(iter);

let min_field_width = parse_quantity(iter)?;

let precision = parse_precision(iter)?;

consume_length(iter);

let format_type = parse_format_type(iter)?;

let spec = CFormatSpec {

flags,

min_field_width,

precision,

format_type,

};

Ok(Self { mapping_key, spec })

}

fn compute_fill_string<T: FormatBuf>(fill_char: T::Char, fill_chars_needed: usize) -> T {

(0..fill_chars_needed).map(|_| fill_char).collect()

}

fn fill_string<T: FormatBuf>(

&self,

string: T,

fill_char: T::Char,

num_prefix_chars: Option<usize>,

) -> T {

let mut num_chars = string.chars().count();

if let Some(num_prefix_chars) = num_prefix_chars {

num_chars += num_prefix_chars;

}

let num_chars = num_chars;

let width = match &self.min_field_width {

Some(CFormatQuantity::Amount(width)) => cmp::max(width, &num_chars),

_ => &num_chars,

};

let fill_chars_needed = width.saturating_sub(num_chars);

let fill_string: T = Self::compute_fill_string(fill_char, fill_chars_needed);

if !fill_string.is_empty() {

if self.flags.contains(CConversionFlags::LEFT_ADJUST) {

string.concat(fill_string)

} else {

fill_string.concat(string)

}

} else {

string

}

}

fn fill_string_with_precision<T: FormatBuf>(&self, string: T, fill_char: T::Char) -> T {

let num_chars = string.chars().count();

let width = match &self.precision {

Some(CFormatPrecision::Quantity(CFormatQuantity::Amount(width))) => {

cmp::max(width, &num_chars)

}

_ => &num_chars,

};

let fill_chars_needed = width.saturating_sub(num_chars);

let fill_string: T = Self::compute_fill_string(fill_char, fill_chars_needed);

if !fill_string.is_empty() {

// Don't left-adjust if precision-filling: that will always be prepending 0s to %d

// arguments, the LEFT_ADJUST flag will be used by a later call to fill_string with

// the 0-filled string as the string param.

fill_string.concat(string)

} else {

string

}

}

fn format_string_with_precision<T: FormatBuf>(

&self,

string: T,

precision: Option<&CFormatPrecision>,

) -> T {

// truncate if needed

let string = match precision {

Some(CFormatPrecision::Quantity(CFormatQuantity::Amount(precision)))

if string.chars().count() > *precision =>

{

string.chars().take(*precision).collect::<T>()

}

Some(CFormatPrecision::Dot) => {

// truncate to 0

T::default()

}

_ => string,

};

self.fill_string(string, b' '.into(), None)

}

#[inline]

pub fn format_string<T: FormatBuf>(&self, string: T) -> T {

self.format_string_with_precision(string, self.precision.as_ref())

}

#[inline]

pub fn format_char<T: FormatBuf>(&self, ch: T::Char) -> T {

self.format_string_with_precision(

T::from_iter([ch]),

Some(&(CFormatQuantity::Amount(1).into())),

)

}

pub fn format_bytes(&self, bytes: &[u8]) -> Vec<u8> {

let bytes = if let Some(CFormatPrecision::Quantity(CFormatQuantity::Amount(precision))) =

self.precision

{

&bytes[..cmp::min(bytes.len(), precision)]

} else {

bytes

};

if let Some(CFormatQuantity::Amount(width)) = self.min_field_width {

let fill = cmp::max(0, width - bytes.len());

let mut v = Vec::with_capacity(bytes.len() + fill);

if self.flags.contains(CConversionFlags::LEFT_ADJUST) {

v.extend_from_slice(bytes);

v.append(&mut vec![b' '; fill]);

} else {

v.append(&mut vec![b' '; fill]);

v.extend_from_slice(bytes);

}

v

} else {

bytes.to_vec()

}

}

pub fn format_number(&self, num: &BigInt) -> String {

use CNumberType::*;

let CFormatType::Number(format_type) = self.format_type else {

unreachable!()

};

let magnitude = num.abs();

let prefix = if self.flags.contains(CConversionFlags::ALTERNATE_FORM) {

match format_type {

Octal => "0o",

HexLower => "0x",

HexUpper => "0X",

_ => "",

}

} else {

""

};

let magnitude_string: String = match format_type {

DecimalD | DecimalI | DecimalU => magnitude.to_str_radix(10),

Octal => magnitude.to_str_radix(8),

HexLower => magnitude.to_str_radix(16),

HexUpper => {

let mut result = magnitude.to_str_radix(16);

result.make_ascii_uppercase();

result

}

};

let sign_string = match num.sign() {

Sign::Minus => "-",

_ => self.flags.sign_string(),

};

let padded_magnitude_string = self.fill_string_with_precision(magnitude_string, '0');

if self.flags.contains(CConversionFlags::ZERO_PAD) {

let fill_char = if !self.flags.contains(CConversionFlags::LEFT_ADJUST) {

'0'

} else {

' ' // '-' overrides the '0' conversion if both are given

};

let signed_prefix = format!("{sign_string}{prefix}");

format!(

"{}{}",

signed_prefix,

self.fill_string(

padded_magnitude_string,

fill_char,

Some(signed_prefix.chars().count()),

),

)

} else {

self.fill_string(

format!("{sign_string}{prefix}{padded_magnitude_string}"),

' ',

None,

)

}

}

pub fn format_float(&self, num: f64) -> String {

let sign_string = if num.is_sign_negative() && !num.is_nan() {

"-"

} else {

self.flags.sign_string()

};

let precision = match &self.precision {

Some(CFormatPrecision::Quantity(quantity)) => match quantity {

CFormatQuantity::Amount(amount) => *amount,

CFormatQuantity::FromValuesTuple => 6,

},

Some(CFormatPrecision::Dot) => 0,

None => 6,

};

let CFormatType::Float(format_type) = self.format_type else {

unreachable!()

};

let magnitude = num.abs();

let case = format_type.case();

let magnitude_string = match format_type {

CFloatType::PointDecimalLower | CFloatType::PointDecimalUpper => float::format_fixed(

precision,

magnitude,

case,

self.flags.contains(CConversionFlags::ALTERNATE_FORM),

),

CFloatType::ExponentLower | CFloatType::ExponentUpper => float::format_exponent(

precision,

magnitude,

case,

self.flags.contains(CConversionFlags::ALTERNATE_FORM),

),

CFloatType::GeneralLower | CFloatType::GeneralUpper => {

let precision = if precision == 0 { 1 } else { precision };

float::format_general(

precision,

magnitude,

case,

self.flags.contains(CConversionFlags::ALTERNATE_FORM),

false,

)

}

};

if self.flags.contains(CConversionFlags::ZERO_PAD) {

let fill_char = if !self.flags.contains(CConversionFlags::LEFT_ADJUST) {

'0'

} else {

' '

};

format!(

"{}{}",

sign_string,

self.fill_string(

magnitude_string,

fill_char,

Some(sign_string.chars().count()),

)

)

} else {

self.fill_string(format!("{sign_string}{magnitude_string}"), ' ', None)

}

}

T: FormatBuf,

I: Iterator<Item = T::Char>,

if let Some((index, _)) = iter.next_if(|(_, c)| c.eq_char('(')) {

return match parse_text_inside_parentheses(iter) {

Some(key) => Ok(Some(key)),

None => Err((CFormatErrorType::UnmatchedKeyParentheses, index)),

};

}

Ok(None)

C: FormatChar,

I: Iterator<Item = C>,

let mut flags = CConversionFlags::empty();

iter.peeking_take_while(|(_, c)| {

let flag = match c.to_char_lossy() {

'#' => CConversionFlags::ALTERNATE_FORM,

'0' => CConversionFlags::ZERO_PAD,

'-' => CConversionFlags::LEFT_ADJUST,

' ' => CConversionFlags::BLANK_SIGN,

'+' => CConversionFlags::SIGN_CHAR,

_ => return false,

};

flags |= flag;

true

})

.for_each(drop);

flags

C: FormatChar,

I: Iterator<Item = C>,

iter.next_if(|(_, c)| matches!(c.to_char_lossy(), 'h' | 'l' | 'L'));

C: FormatChar,

I: Iterator<Item = C>,

use CFloatType::*;

use CNumberType::*;

let (index, c) = iter.next().ok_or_else(|| {

(

CFormatErrorType::IncompleteFormat,

iter.peek().map(|x| x.0).unwrap_or(0),

)

})?;

let format_type = match c.to_char_lossy() {

'd' => CFormatType::Number(DecimalD),

'i' => CFormatType::Number(DecimalI),

'u' => CFormatType::Number(DecimalU),

'o' => CFormatType::Number(Octal),

'x' => CFormatType::Number(HexLower),

'X' => CFormatType::Number(HexUpper),

'e' => CFormatType::Float(ExponentLower),

'E' => CFormatType::Float(ExponentUpper),

'f' => CFormatType::Float(PointDecimalLower),

'F' => CFormatType::Float(PointDecimalUpper),

'g' => CFormatType::Float(GeneralLower),

'G' => CFormatType::Float(GeneralUpper),

'c' => CFormatType::Character(CCharacterType::Character),

'r' => CFormatType::String(CFormatConversion::Repr),

's' => CFormatType::String(CFormatConversion::Str),

'b' => CFormatType::String(CFormatConversion::Bytes),

'a' => CFormatType::String(CFormatConversion::Ascii),

_ => return Err((CFormatErrorType::UnsupportedFormatChar(c.into()), index)),

};

Ok(format_type)

C: FormatChar,

I: Iterator<Item = C>,

if let Some(&(_, c)) = iter.peek() {

if c.eq_char('*') {

iter.next().unwrap();

return Ok(Some(CFormatQuantity::FromValuesTuple));

}

if let Some(i) = c.to_char_lossy().to_digit(10) {

let mut num = i as i32;

iter.next().unwrap();

while let Some(&(index, c)) = iter.peek() {

if let Some(i) = c.to_char_lossy().to_digit(10) {

num = num

.checked_mul(10)

.and_then(|num| num.checked_add(i as i32))

.ok_or((CFormatErrorType::IntTooBig, index))?;

iter.next().unwrap();

} else {

break;

}

}

return Ok(Some(CFormatQuantity::Amount(num.unsigned_abs() as usize)));

}

}

Ok(None)

C: FormatChar,

I: Iterator<Item = C>,

if iter.next_if(|(_, c)| c.eq_char('.')).is_some() {

let quantity = parse_quantity(iter)?;

let precision = quantity.map_or(CFormatPrecision::Dot, CFormatPrecision::Quantity);

return Ok(Some(precision));

}

Ok(None)

T: FormatBuf,

I: Iterator<Item = T::Char>,

let mut counter: i32 = 1;

let mut contained_text = T::default();

loop {

let (_, c) = iter.next()?;

match c.to_char_lossy() {

'(' => {

counter += 1;

}

')' => {

counter -= 1;

}

_ => (),

}

if counter > 0 {

contained_text.extend([c]);

} else {

break;

}

}

Some(contained_text)

#[inline]

pub const fn is_specifier(&self) -> bool {

matches!(self, Self::Spec { .. })

}

#[inline]

pub const fn has_key(&self) -> bool {

match self {

Self::Spec(s) => s.mapping_key.is_some(),

_ => false,

}

}

pub fn check_specifiers(&self) -> Option<(usize, bool)> {

let mut count = 0;

let mut mapping_required = false;

for (_, part) in &self.parts {

if part.is_specifier() {

let has_key = part.has_key();

if count == 0 {

mapping_required = has_key;

} else if mapping_required != has_key {

return None;

}

count += 1;

}

}

Some((count, mapping_required))

}

#[inline]

pub fn iter(&self) -> impl Iterator<Item = &(usize, CFormatPart<S>)> {

self.parts.iter()

}

#[inline]

pub fn iter_mut(&mut self) -> impl Iterator<Item = &mut (usize, CFormatPart<S>)> {

self.parts.iter_mut()

}

pub fn parse<I>(iter: &mut ParseIter<I>) -> Result<Self, CFormatError>

where

S: FormatBuf,

I: Iterator<Item = S::Char>,

{

let mut parts = vec![];

let mut literal = S::default();

let mut part_index = 0;

while let Some((index, c)) = iter.next() {

if c.eq_char('%') {

if let Some(&(_, second)) = iter.peek() {

if second.eq_char('%') {

iter.next().unwrap();

literal.extend([second]);

continue;

} else {

if !literal.is_empty() {

parts.push((

part_index,

CFormatPart::Literal(core::mem::take(&mut literal)),

));

}

let spec = CFormatSpecKeyed::parse(iter).map_err(|err| CFormatError {

typ: err.0,

index: err.1,

})?;

parts.push((index, CFormatPart::Spec(spec)));

if let Some(&(index, _)) = iter.peek() {

part_index = index;

}

}

} else {

return Err(CFormatError {

typ: CFormatErrorType::IncompleteFormat,

index: index + 1,

});

}

} else {

literal.extend([c]);

}

}

if !literal.is_empty() {

parts.push((part_index, CFormatPart::Literal(literal)));

}

Ok(Self { parts })

}

type Item = (usize, CFormatPart<S>);

type IntoIter = alloc::vec::IntoIter<Self::Item>;

fn into_iter(self) -> Self::IntoIter {

self.parts.into_iter()

}

pub fn parse_from_bytes(bytes: &[u8]) -> Result<Self, CFormatError> {