//! Low-level API generator.
//!
//! Uses either the imprecise or the precise algorithm.

use crate::lib::slice;
use crate::util::*;

// Select the back-end
cfg_if! {
if #[cfg(feature = "correct")] {
    use super::algorithm::correct as algorithm;
} else {
    use super::algorithm::incorrect as algorithm;
}}  // cfg_if

// TRAITS

/// Trait to define parsing of a string to float.
trait StringToFloat: Float {
    /// Serialize string to float, favoring correctness.
    fn default(bytes: &[u8], radix: u32, lossy: bool, sign: Sign, format: NumberFormat) -> ParseResult<(Self, *const u8)>;
}

impl StringToFloat for f32 {
    perftools_inline_always!{
    fn default(bytes: &[u8], radix: u32, lossy: bool, sign: Sign, format: NumberFormat)
        -> ParseResult<(f32, *const u8)>
    {
        algorithm::atof(bytes, radix, lossy, sign, format)
    }}
}

impl StringToFloat for f64 {
    perftools_inline_always!{
    fn default(bytes: &[u8], radix: u32, lossy: bool, sign: Sign, format: NumberFormat)
        -> ParseResult<(f64, *const u8)>
    {
        algorithm::atod(bytes, radix, lossy, sign, format)
    }}
}

// SPECIAL
// Utilities to filter special values.

// Convert slice to iterator without digit separators.
perftools_inline!{
fn to_iter<'a>(bytes: &'a [u8], _: u8) -> slice::Iter<'a, u8> {
    bytes.iter()
}}

// Convert slice to iterator with digit separators.
perftools_inline!{
#[cfg(feature = "format")]
fn to_iter_s<'a>(bytes: &'a [u8], digit_separator: u8) -> SkipValueIterator<'a, u8> {
    SkipValueIterator::new(bytes, digit_separator)
}}

// PARSER

// Parse infinity from string.
perftools_inline!{
fn parse_infinity<'a, ToIter, StartsWith, Iter, F>(
    bytes: &'a [u8],
    radix: u32,
    lossy: bool,
    sign: Sign,
    format: NumberFormat,
    to_iter: ToIter,
    starts_with: StartsWith
)
    -> ParseResult<(F, *const u8)>
    where F: StringToFloat,
          ToIter: Fn(&'a [u8], u8) -> Iter,
          Iter: AsPtrIterator<'a, u8>,
          StartsWith: Fn(Iter, slice::Iter<'a, u8>) -> (bool, Iter)
{
    let infinity = get_infinity_string();
    let inf = get_inf_string();
    if let (true, iter) = starts_with(to_iter(bytes, format.digit_separator()), infinity.iter()) {
        Ok((F::INFINITY, iter.as_ptr()))
    } else if let (true, iter) = starts_with(to_iter(bytes, format.digit_separator()), inf.iter()) {
        Ok((F::INFINITY, iter.as_ptr()))
    } else {
        // Not infinity, may be valid with a different radix.
        if cfg!(feature = "radix"){
            F::default(bytes, radix, lossy, sign, format)
        } else {
            Err((ErrorCode::InvalidDigit, bytes.as_ptr()))
        }
    }
}}

// Parse NaN from string.
perftools_inline!{
fn parse_nan<'a, ToIter, StartsWith, Iter, F>(
    bytes: &'a [u8],
    radix: u32,
    lossy: bool,
    sign: Sign,
    format: NumberFormat,
    to_iter: ToIter,
    starts_with: StartsWith
)
-> ParseResult<(F, *const u8)>
    where F: StringToFloat,
          ToIter: Fn(&'a [u8], u8) -> Iter,
          Iter: AsPtrIterator<'a, u8>,
          StartsWith: Fn(Iter, slice::Iter<'a, u8>) -> (bool, Iter)
{
    let nan = get_nan_string();
    if let (true, iter) = starts_with(to_iter(bytes, format.digit_separator()), nan.iter()) {
        Ok((F::NAN, iter.as_ptr()))
    } else {
        // Not NaN, may be valid with a different radix.
        if cfg!(feature = "radix"){
            F::default(bytes, radix, lossy, sign, format)
        } else {
            Err((ErrorCode::InvalidDigit, bytes.as_ptr()))
        }
    }
}}

// ATOF/ATOD

// Parse special or float values with the standard format.
// Special values are allowed, the match is case-insensitive,
// and no digit separators are allowed.
perftools_inline!{
fn parse_float_standard<F: StringToFloat>(bytes: &[u8], radix: u32, lossy: bool, sign: Sign, format: NumberFormat)
    -> ParseResult<(F, *const u8)>
{
    // Use predictive parsing to filter special cases. This leads to
    // dramatic performance gains.
    let starts_with = case_insensitive_starts_with_iter;
    match index!(bytes[0]) {
        b'i' | b'I' => parse_infinity(bytes, radix, lossy, sign, format, to_iter, starts_with),
        b'N' | b'n' => parse_nan(bytes, radix, lossy, sign, format, to_iter, starts_with),
        _           => F::default(bytes, radix, lossy, sign, format),
    }
}}

// Parse special or float values.
// Special values are allowed, the match is case-sensitive,
// and digit separators are allowed.
perftools_inline!{
#[cfg(feature = "format")]
fn parse_float_cs<F: StringToFloat>(bytes: &[u8], radix: u32, lossy: bool, sign: Sign, format: NumberFormat)
    -> ParseResult<(F, *const u8)>
{
    let digit_separator = format.digit_separator();
    let starts_with = starts_with_iter;
    match SkipValueIterator::new(bytes, digit_separator).next()  {
        Some(&b'i') | Some(&b'I')   => parse_infinity(bytes, radix, lossy, sign, format, to_iter_s, starts_with),
        Some(&b'n') | Some(&b'N')   => parse_nan(bytes, radix, lossy, sign, format, to_iter_s, starts_with),
        _                           => F::default(bytes, radix, lossy, sign, format),
    }
}}

// Parse special or float values.
// Special values are allowed, the match is case-sensitive,
// and no digit separators are allowed.
perftools_inline!{
#[cfg(feature = "format")]
fn parse_float_c<F: StringToFloat>(bytes: &[u8], radix: u32, lossy: bool, sign: Sign, format: NumberFormat)
    -> ParseResult<(F, *const u8)>
{
    // Use predictive parsing to filter special cases. This leads to
    // dramatic performance gains.
    let starts_with = starts_with_iter;
    match index!(bytes[0]) {
        b'i' | b'I' => parse_infinity(bytes, radix, lossy, sign, format, to_iter, starts_with),
        b'N' | b'n' => parse_nan(bytes, radix, lossy, sign, format, to_iter, starts_with),
        _           => F::default(bytes, radix, lossy, sign, format),
    }
}}

// Parse special or float values.
// Special values are allowed, the match is case-insensitive,
// and digit separators are allowed.
perftools_inline!{
#[cfg(feature = "format")]
fn parse_float_s<F: StringToFloat>(bytes: &[u8], radix: u32, lossy: bool, sign: Sign, format: NumberFormat)
    -> ParseResult<(F, *const u8)>
{
    let digit_separator = format.digit_separator();
    let starts_with = case_insensitive_starts_with_iter;
    match SkipValueIterator::new(bytes, digit_separator).next()  {
        Some(&b'i') | Some(&b'I')   => parse_infinity(bytes, radix, lossy, sign, format, to_iter_s, starts_with),
        Some(&b'n') | Some(&b'N')   => parse_nan(bytes, radix, lossy, sign, format, to_iter_s, starts_with),
        _                           => F::default(bytes, radix, lossy, sign, format),
    }
}}

// Parse special or float values with the default formatter.
perftools_inline!{
#[cfg(not(feature = "format"))]
fn parse_float<F: StringToFloat>(bytes: &[u8], radix: u32, lossy: bool, sign: Sign, format: NumberFormat)
    -> ParseResult<(F, *const u8)>
{
    parse_float_standard(bytes, radix, lossy, sign, format)
}}

// Parse special or float values with the default formatter.
perftools_inline!{
#[cfg(feature = "format")]
fn parse_float<F: StringToFloat>(bytes: &[u8], radix: u32, lossy: bool, sign: Sign, format: NumberFormat)
    -> ParseResult<(F, *const u8)>
{
    // Need to consider 3 possibilities:
    //  1). No special values are allowed.
    //  2). Special values are case-sensitive.
    //  3). Digit separators are allowed in the special.
    let no_special = format.no_special();
    let case = format.case_sensitive_special();
    let has_sep = format.special_digit_separator();
    match (no_special, case, has_sep) {
        (true, _, _)            => F::default(bytes, radix, lossy, sign, format),
        (false, true, true)     => parse_float_cs(bytes, radix, lossy, sign, format),
        (false, false, true)    => parse_float_s(bytes, radix, lossy, sign, format),
        (false, true, false)    => parse_float_c(bytes, radix, lossy, sign, format),
        (false, false, false)   => parse_float_standard(bytes, radix, lossy, sign, format),
    }
}}

// Validate sign byte is valid.
perftools_inline!{
#[cfg(not(feature = "format"))]
fn validate_sign(_: &[u8], _: &[u8], _: Sign, _: NumberFormat)
    -> ParseResult<()>
{
    Ok(())
}}

// Validate sign byte is valid.
perftools_inline!{
#[cfg(feature = "format")]
fn validate_sign(bytes: &[u8], digits: &[u8], sign: Sign, format: NumberFormat)
    -> ParseResult<()>
{
    let has_sign = bytes.as_ptr() != digits.as_ptr();
    if format.no_positive_mantissa_sign() && has_sign && sign == Sign::Positive {
        Err((ErrorCode::InvalidPositiveMantissaSign, bytes.as_ptr()))
    } else if format.required_mantissa_sign() && !has_sign {
        Err((ErrorCode::MissingMantissaSign, bytes.as_ptr()))
    } else {
        Ok(())
    }
}}

// Convert float to signed representation.
perftools_inline!{
fn to_signed<F: StringToFloat>(float: F, sign: Sign) -> F
{
    match sign {
        Sign::Positive => float,
        Sign::Negative => -float
    }
}}

// Standalone atof processor.
perftools_inline!{
fn atof<F: StringToFloat>(bytes: &[u8], radix: u32, lossy: bool, format: NumberFormat)
    -> ParseResult<(F, *const u8)>
{
    let (sign, digits) = parse_sign::<F>(bytes, format);
    if digits.is_empty() {
        return Err((ErrorCode::Empty, digits.as_ptr()));
    }
    let (float, ptr): (F, *const u8) = parse_float(digits, radix, lossy, sign, format)?;
    validate_sign(bytes, digits, sign, format)?;

    Ok((to_signed(float, sign), ptr))
}}

perftools_inline!{
fn atof_lossy<F: StringToFloat>(bytes: &[u8], radix: u32)
    -> Result<(F, usize)>
{
    let index = | ptr | distance(bytes.as_ptr(), ptr);
    match atof::<F>(bytes, radix, true, NumberFormat::standard().unwrap()) {
        Ok((value, ptr)) => Ok((value, index(ptr))),
        Err((code, ptr)) => Err((code, index(ptr)).into()),
    }
}}

perftools_inline!{
fn atof_nonlossy<F: StringToFloat>(bytes: &[u8], radix: u32)
    -> Result<(F, usize)>
{
    let index = | ptr | distance(bytes.as_ptr(), ptr);
    match atof::<F>(bytes, radix, false, NumberFormat::standard().unwrap()) {
        Ok((value, ptr)) => Ok((value, index(ptr))),
        Err((code, ptr)) => Err((code, index(ptr)).into()),
    }
}}

perftools_inline!{
#[cfg(feature = "format")]
fn atof_format<F: StringToFloat>(bytes: &[u8], radix: u32, format: NumberFormat)
    -> Result<(F, usize)>
{
    let index = | ptr | distance(bytes.as_ptr(), ptr);
    match atof::<F>(bytes, radix, false, format) {
        Ok((value, ptr)) => Ok((value, index(ptr))),
        Err((code, ptr)) => Err((code, index(ptr)).into()),
    }
}}

perftools_inline!{
#[cfg(feature = "format")]
fn atof_lossy_format<F: StringToFloat>(bytes: &[u8], radix: u32, format: NumberFormat)
    -> Result<(F, usize)>
{
    let index = | ptr | distance(bytes.as_ptr(), ptr);
    match atof::<F>(bytes, radix, true, format) {
        Ok((value, ptr)) => Ok((value, index(ptr))),
        Err((code, ptr)) => Err((code, index(ptr)).into()),
    }
}}

// FROM LEXICAL
// ------------

from_lexical!(atof_nonlossy, f32);
from_lexical!(atof_nonlossy, f64);
from_lexical_lossy!(atof_lossy, f32);
from_lexical_lossy!(atof_lossy, f64);

cfg_if!{
if #[cfg(feature = "format")] {
    from_lexical_format!(atof_format, f32);
    from_lexical_format!(atof_format, f64);
    from_lexical_lossy_format!(atof_lossy_format, f32);
    from_lexical_lossy_format!(atof_lossy_format, f64);
}}

// TESTS
// -----

#[cfg(test)]
mod tests {
    use crate::util::*;

    use approx::assert_relative_eq;
    #[cfg(all(feature = "std", feature = "property_tests"))]
    use proptest::{proptest, prop_assert_eq, prop_assert};

    #[test]
    fn f32_decimal_test() {
        // integer test
        assert_f32_eq!(0.0, f32::from_lexical(b"0").unwrap());
        assert_f32_eq!(1.0, f32::from_lexical(b"1").unwrap());
        assert_f32_eq!(12.0, f32::from_lexical(b"12").unwrap());
        assert_f32_eq!(123.0, f32::from_lexical(b"123").unwrap());
        assert_f32_eq!(1234.0, f32::from_lexical(b"1234").unwrap());
        assert_f32_eq!(12345.0, f32::from_lexical(b"12345").unwrap());
        assert_f32_eq!(123456.0, f32::from_lexical(b"123456").unwrap());
        assert_f32_eq!(1234567.0, f32::from_lexical(b"1234567").unwrap());
        assert_f32_eq!(12345678.0, f32::from_lexical(b"12345678").unwrap());

         // No fraction after decimal point test
        assert_f32_eq!(1.0, f32::from_lexical(b"1.").unwrap());
        assert_f32_eq!(12.0, f32::from_lexical(b"12.").unwrap());
        assert_f32_eq!(1234567.0, f32::from_lexical(b"1234567.").unwrap());

        // No integer before decimal point test
        assert_f32_eq!(0.1, f32::from_lexical(b".1").unwrap());
        assert_f32_eq!(0.12, f32::from_lexical(b".12").unwrap());
        assert_f32_eq!(0.1234567, f32::from_lexical(b".1234567").unwrap());

        // decimal test
        assert_f32_eq!(123.1, f32::from_lexical(b"123.1").unwrap());
        assert_f32_eq!(123.12, f32::from_lexical(b"123.12").unwrap());
        assert_f32_eq!(123.123, f32::from_lexical(b"123.123").unwrap());
        assert_f32_eq!(123.1234, f32::from_lexical(b"123.1234").unwrap());
        assert_f32_eq!(123.12345, f32::from_lexical(b"123.12345").unwrap());

        // rounding test
        assert_f32_eq!(123456790.0, f32::from_lexical(b"123456789").unwrap());
        assert_f32_eq!(123456790.0, f32::from_lexical(b"123456789.1").unwrap());
        assert_f32_eq!(123456790.0, f32::from_lexical(b"123456789.12").unwrap());
        assert_f32_eq!(123456790.0, f32::from_lexical(b"123456789.123").unwrap());
        assert_f32_eq!(123456790.0, f32::from_lexical(b"123456789.1234").unwrap());
        assert_f32_eq!(123456790.0, f32::from_lexical(b"123456789.12345").unwrap());

        // exponent test
        assert_f32_eq!(123456789.12345, f32::from_lexical(b"1.2345678912345e8").unwrap());
        assert_f32_eq!(123450000.0, f32::from_lexical(b"1.2345e+8").unwrap());
        assert_f32_eq!(1.2345e+11, f32::from_lexical(b"1.2345e+11").unwrap());
        assert_f32_eq!(1.2345e+11, f32::from_lexical(b"123450000000").unwrap());
        assert_f32_eq!(1.2345e+38, f32::from_lexical(b"1.2345e+38").unwrap());
        assert_f32_eq!(1.2345e+38, f32::from_lexical(b"123450000000000000000000000000000000000").unwrap());
        assert_f32_eq!(1.2345e-8, f32::from_lexical(b"1.2345e-8").unwrap());
        assert_f32_eq!(1.2345e-8, f32::from_lexical(b"0.000000012345").unwrap());
        assert_f32_eq!(1.2345e-38, f32::from_lexical(b"1.2345e-38").unwrap());
        assert_f32_eq!(1.2345e-38, f32::from_lexical(b"0.000000000000000000000000000000000000012345").unwrap());

        assert!(f32::from_lexical(b"NaN").unwrap().is_nan());
        assert!(f32::from_lexical(b"nan").unwrap().is_nan());
        assert!(f32::from_lexical(b"NAN").unwrap().is_nan());
        assert!(f32::from_lexical(b"inf").unwrap().is_infinite());
        assert!(f32::from_lexical(b"INF").unwrap().is_infinite());
        assert!(f32::from_lexical(b"+inf").unwrap().is_infinite());
        assert!(f32::from_lexical(b"-inf").unwrap().is_infinite());

        // Check various expected failures.
        assert_eq!(Err(ErrorCode::Empty.into()), f32::from_lexical(b""));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f32::from_lexical(b"e"));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f32::from_lexical(b"E"));
        assert_eq!(Err(ErrorCode::EmptyMantissa.into()), f32::from_lexical(b".e1"));
        assert_eq!(Err(ErrorCode::EmptyMantissa.into()), f32::from_lexical(b".e-1"));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f32::from_lexical(b"e1"));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f32::from_lexical(b"e-1"));
        assert_eq!(Err((ErrorCode::Empty, 1).into()), f32::from_lexical(b"+"));
        assert_eq!(Err((ErrorCode::Empty, 1).into()), f32::from_lexical(b"-"));

        // Bug fix for Issue #8
        assert_eq!(Ok(5.002868148396374), f32::from_lexical(b"5.002868148396374"));
    }

    #[cfg(feature = "radix")]
    #[test]
    fn f32_radix_test() {
        assert_f32_eq!(1234.0, f32::from_lexical_radix(b"YA", 36).unwrap());
        assert_f32_eq!(1234.0, f32::from_lexical_lossy_radix(b"YA", 36).unwrap());
    }

    #[test]
    fn f64_decimal_test() {
        // integer test
        assert_f64_eq!(0.0, f64::from_lexical(b"0").unwrap());
        assert_f64_eq!(1.0, f64::from_lexical(b"1").unwrap());
        assert_f64_eq!(12.0, f64::from_lexical(b"12").unwrap());
        assert_f64_eq!(123.0, f64::from_lexical(b"123").unwrap());
        assert_f64_eq!(1234.0, f64::from_lexical(b"1234").unwrap());
        assert_f64_eq!(12345.0, f64::from_lexical(b"12345").unwrap());
        assert_f64_eq!(123456.0, f64::from_lexical(b"123456").unwrap());
        assert_f64_eq!(1234567.0, f64::from_lexical(b"1234567").unwrap());
        assert_f64_eq!(12345678.0, f64::from_lexical(b"12345678").unwrap());

        // No fraction after decimal point test
        assert_f64_eq!(1.0, f64::from_lexical(b"1.").unwrap());
        assert_f64_eq!(12.0, f64::from_lexical(b"12.").unwrap());
        assert_f64_eq!(1234567.0, f64::from_lexical(b"1234567.").unwrap());

        // No integer before decimal point test
        assert_f64_eq!(0.1, f64::from_lexical(b".1").unwrap());
        assert_f64_eq!(0.12, f64::from_lexical(b".12").unwrap());
        assert_f64_eq!(0.1234567, f64::from_lexical(b".1234567").unwrap());

        // decimal test
        assert_f64_eq!(123456789.0, f64::from_lexical(b"123456789").unwrap());
        assert_f64_eq!(123456789.1, f64::from_lexical(b"123456789.1").unwrap());
        assert_f64_eq!(123456789.12, f64::from_lexical(b"123456789.12").unwrap());
        assert_f64_eq!(123456789.123, f64::from_lexical(b"123456789.123").unwrap());
        assert_f64_eq!(123456789.1234, f64::from_lexical(b"123456789.1234").unwrap());
        assert_f64_eq!(123456789.12345, f64::from_lexical(b"123456789.12345").unwrap());
        assert_f64_eq!(123456789.123456, f64::from_lexical(b"123456789.123456").unwrap());
        assert_f64_eq!(123456789.1234567, f64::from_lexical(b"123456789.1234567").unwrap());
        assert_f64_eq!(123456789.12345678, f64::from_lexical(b"123456789.12345678").unwrap());

        // rounding test
        assert_f64_eq!(123456789.12345679, f64::from_lexical(b"123456789.123456789").unwrap());
        assert_f64_eq!(123456789.12345679, f64::from_lexical(b"123456789.1234567890").unwrap());
        assert_f64_eq!(123456789.12345679, f64::from_lexical(b"123456789.123456789012").unwrap());
        assert_f64_eq!(123456789.12345679, f64::from_lexical(b"123456789.1234567890123").unwrap());
        assert_f64_eq!(123456789.12345679, f64::from_lexical(b"123456789.12345678901234").unwrap());

        // exponent test
        assert_f64_eq!(123456789.12345, f64::from_lexical(b"1.2345678912345e8").unwrap());
        assert_f64_eq!(123450000.0, f64::from_lexical(b"1.2345e+8").unwrap());
        assert_f64_eq!(1.2345e+11, f64::from_lexical(b"123450000000").unwrap());
        assert_f64_eq!(1.2345e+11, f64::from_lexical(b"1.2345e+11").unwrap());
        assert_f64_eq!(1.2345e+38, f64::from_lexical(b"1.2345e+38").unwrap());
        assert_f64_eq!(1.2345e+38, f64::from_lexical(b"123450000000000000000000000000000000000").unwrap());
        assert_f64_eq!(1.2345e+308, f64::from_lexical(b"1.2345e+308").unwrap());
        assert_f64_eq!(1.2345e+308, f64::from_lexical(b"123450000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000").unwrap());
        assert_f64_eq!(0.000000012345, f64::from_lexical(b"1.2345e-8").unwrap());
        assert_f64_eq!(1.2345e-8, f64::from_lexical(b"0.000000012345").unwrap());
        assert_f64_eq!(1.2345e-38, f64::from_lexical(b"1.2345e-38").unwrap());
        assert_f64_eq!(1.2345e-38, f64::from_lexical(b"0.000000000000000000000000000000000000012345").unwrap());

        // denormalized (try extremely low values)
        assert_f64_eq!(1.2345e-308, f64::from_lexical(b"1.2345e-308").unwrap());
        // These next 3 tests fail on arm-unknown-linux-gnueabi with the
        // incorrect parser.
        #[cfg(all(not(feature = "correct"), not(target_arch = "arm")))]
        assert_eq!(Ok(5e-322), f64::from_lexical(b"5e-322"));
        #[cfg(all(not(feature = "correct"), not(target_arch = "arm")))]
        assert_eq!(Ok(5e-323), f64::from_lexical(b"5e-323"));
        #[cfg(all(not(feature = "correct"), not(target_arch = "arm")))]
        assert_eq!(Ok(5e-324), f64::from_lexical(b"5e-324"));
        // due to issues in how the data is parsed, manually extracting
        // non-exponents of 1.<e-299 is prone to error
        // test the limit of our ability
        // We tend to get relative errors of 1e-16, even at super low values.
        assert_f64_eq!(1.2345e-299, f64::from_lexical(b"0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000012345").unwrap(), epsilon=1e-314);

        // Keep pushing from -300 to -324
        assert_f64_eq!(1.2345e-300, f64::from_lexical(b"0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000012345").unwrap(), epsilon=1e-315);

        // These next 3 tests fail on arm-unknown-linux-gnueabi with the
        // incorrect parser.
        #[cfg(all(not(feature = "correct"), not(target_arch = "arm")))]
        assert_f64_eq!(1.2345e-310, f64::from_lexical(b"0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000012345").unwrap(), epsilon=5e-324);
        #[cfg(all(not(feature = "correct"), not(target_arch = "arm")))]
        assert_f64_eq!(1.2345e-320, f64::from_lexical(b"0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000012345").unwrap(), epsilon=5e-324);
        #[cfg(all(not(feature = "correct"), not(target_arch = "arm")))]
        assert_f64_eq!(1.2345e-321, f64::from_lexical(b"0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000012345").unwrap(), epsilon=5e-324);
        #[cfg(all(not(feature = "correct"), not(target_arch = "arm")))]
        assert_f64_eq!(1.24e-322, f64::from_lexical(b"0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000124").unwrap(), epsilon=5e-324);
        #[cfg(all(not(feature = "correct"), not(target_arch = "arm")))]
        assert_eq!(Ok(1e-323), f64::from_lexical(b"0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001"));
        #[cfg(all(not(feature = "correct"), not(target_arch = "arm")))]
        assert_eq!(Ok(5e-324), f64::from_lexical(b"0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000005"));

        assert!(f64::from_lexical(b"NaN").unwrap().is_nan());
        assert!(f64::from_lexical(b"nan").unwrap().is_nan());
        assert!(f64::from_lexical(b"NAN").unwrap().is_nan());
        assert!(f64::from_lexical(b"inf").unwrap().is_infinite());
        assert!(f64::from_lexical(b"INF").unwrap().is_infinite());
        assert!(f64::from_lexical(b"+inf").unwrap().is_infinite());
        assert!(f64::from_lexical(b"-inf").unwrap().is_infinite());

        // Check various expected failures.
        assert_eq!(Err(ErrorCode::Empty.into()), f64::from_lexical(b""));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f64::from_lexical(b"e"));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f64::from_lexical(b"E"));
        assert_eq!(Err(ErrorCode::EmptyMantissa.into()), f64::from_lexical(b".e1"));
        assert_eq!(Err(ErrorCode::EmptyMantissa.into()), f64::from_lexical(b".e-1"));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f64::from_lexical(b"e1"));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f64::from_lexical(b"e-1"));

        // Check various reports from a fuzzer.
        assert_eq!(Err((ErrorCode::EmptyExponent, 2).into()), f64::from_lexical(b"0e"));
        assert_eq!(Err((ErrorCode::EmptyExponent, 4).into()), f64::from_lexical(b"0.0e"));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f64::from_lexical(b".E"));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f64::from_lexical(b".e"));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f64::from_lexical(b"E2252525225"));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f64::from_lexical(b"e2252525225"));
        assert_eq!(Ok(f64::INFINITY), f64::from_lexical(b"2E200000000000"));

        // Add various unittests from proptests.
        assert_eq!(Err((ErrorCode::EmptyExponent, 2).into()), f64::from_lexical(b"0e"));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 0).into()), f64::from_lexical(b"."));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 1).into()), f64::from_lexical(b"+."));
        assert_eq!(Err((ErrorCode::EmptyMantissa, 1).into()), f64::from_lexical(b"-."));
        assert_eq!(Err((ErrorCode::Empty, 1).into()), f64::from_lexical(b"+"));
        assert_eq!(Err((ErrorCode::Empty, 1).into()), f64::from_lexical(b"-"));

        // Bug fix for Issue #8
        assert_eq!(Ok(5.002868148396374), f64::from_lexical(b"5.002868148396374"));
    }

    #[test]
    #[should_panic]
    fn limit_test() {
        assert_relative_eq!(1.2345e-320, 0.0, epsilon=5e-324);
    }

    #[cfg(feature = "radix")]
    #[test]
    fn f64_radix_test() {
        assert_f64_eq!(1234.0, f64::from_lexical_radix(b"YA", 36).unwrap());
        assert_f64_eq!(1234.0, f64::from_lexical_lossy_radix(b"YA", 36).unwrap());
    }

    #[test]
    fn f32_lossy_decimal_test() {
        assert_eq!(Err(ErrorCode::EmptyMantissa.into()), f32::from_lexical_lossy(b"."));
        assert_eq!(Err(ErrorCode::Empty.into()), f32::from_lexical_lossy(b""));
        assert_eq!(Ok(0.0), f32::from_lexical_lossy(b"0.0"));
        assert_eq!(Err((ErrorCode::InvalidDigit, 1).into()), f32::from_lexical_lossy(b"1a"));

        // Bug fix for Issue #8
        assert_eq!(Ok(5.002868148396374), f32::from_lexical_lossy(b"5.002868148396374"));
    }

    #[test]
    fn f64_lossy_decimal_test() {
        assert_eq!(Err(ErrorCode::EmptyMantissa.into()), f64::from_lexical_lossy(b"."));
        assert_eq!(Err(ErrorCode::Empty.into()), f64::from_lexical_lossy(b""));
        assert_eq!(Ok(0.0), f64::from_lexical_lossy(b"0.0"));
        assert_eq!(Err((ErrorCode::InvalidDigit, 1).into()), f64::from_lexical_lossy(b"1a"));

        // Bug fix for Issue #8
        assert_eq!(Ok(5.002868148396374), f64::from_lexical_lossy(b"5.002868148396374"));
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_special_test() {
        //  Comments match (no_special, case_sensitive, has_sep)
        let f1 = NumberFormat::standard().unwrap();         // false, false, false
        let f2 = NumberFormat::ignore(b'_').unwrap();       // false, false, true
        let f3 = f1 | NumberFormat::NO_SPECIAL;             // true, _, _
        let f4 = f1 | NumberFormat::CASE_SENSITIVE_SPECIAL; // false, true, false
        let f5 = f2 | NumberFormat::CASE_SENSITIVE_SPECIAL; // false, true, true

        // Easy NaN
        assert!(f64::from_lexical_format(b"NaN", f1).unwrap().is_nan());
        assert!(f64::from_lexical_format(b"NaN", f2).unwrap().is_nan());
        assert!(f64::from_lexical_format(b"NaN", f3).is_err());
        assert!(f64::from_lexical_format(b"NaN", f4).unwrap().is_nan());
        assert!(f64::from_lexical_format(b"NaN", f5).unwrap().is_nan());

        // Case-sensitive NaN.
        assert!(f64::from_lexical_format(b"nan", f1).unwrap().is_nan());
        assert!(f64::from_lexical_format(b"nan", f2).unwrap().is_nan());
        assert!(f64::from_lexical_format(b"nan", f3).is_err());
        assert!(f64::from_lexical_format(b"nan", f4).is_err());
        assert!(f64::from_lexical_format(b"nan", f5).is_err());

        // Digit-separator NaN.
        assert!(f64::from_lexical_format(b"N_aN", f1).is_err());
        assert!(f64::from_lexical_format(b"N_aN", f2).unwrap().is_nan());
        assert!(f64::from_lexical_format(b"N_aN", f3).is_err());
        assert!(f64::from_lexical_format(b"N_aN", f4).is_err());
        assert!(f64::from_lexical_format(b"N_aN", f5).unwrap().is_nan());

        // Digit-separator + case-sensitive NaN.
        assert!(f64::from_lexical_format(b"n_an", f1).is_err());
        assert!(f64::from_lexical_format(b"n_an", f2).unwrap().is_nan());
        assert!(f64::from_lexical_format(b"n_an", f3).is_err());
        assert!(f64::from_lexical_format(b"n_an", f4).is_err());
        assert!(f64::from_lexical_format(b"n_an", f5).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_required_integer_digits_test() {
        let format = NumberFormat::REQUIRED_INTEGER_DIGITS;
        assert!(f64::from_lexical_format(b"+3.0", format).is_ok());
        assert!(f64::from_lexical_format(b"3.0", format).is_ok());
        assert!(f64::from_lexical_format(b".0", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_required_fraction_digits_test() {
        let format = NumberFormat::REQUIRED_FRACTION_DIGITS;
        assert!(f64::from_lexical_format(b"+3.0", format).is_ok());
        assert!(f64::from_lexical_format(b"3.0", format).is_ok());
        assert!(f64::from_lexical_format(b"3.", format).is_err());
        assert!(f64::from_lexical_format(b"3", format).is_ok());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_required_digits_test() {
        let format = NumberFormat::REQUIRED_DIGITS;
        assert!(f64::from_lexical_format(b"+3.0", format).is_ok());
        assert!(f64::from_lexical_format(b"3.0", format).is_ok());
        assert!(f64::from_lexical_format(b"3.", format).is_err());
        assert!(f64::from_lexical_format(b"3", format).is_ok());
        assert!(f64::from_lexical_format(b".0", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_no_positive_mantissa_sign_test() {
        let format = NumberFormat::NO_POSITIVE_MANTISSA_SIGN;
        assert!(f64::from_lexical_format(b"+3.0", format).is_err());
        assert!(f64::from_lexical_format(b"-3.0", format).is_ok());
        assert!(f64::from_lexical_format(b"3.0", format).is_ok());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_required_mantissa_sign_test() {
        let format = NumberFormat::REQUIRED_MANTISSA_SIGN;
        assert!(f64::from_lexical_format(b"+3.0", format).is_ok());
        assert!(f64::from_lexical_format(b"-3.0", format).is_ok());
        assert!(f64::from_lexical_format(b"3.0", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_no_exponent_notation_test() {
        let format = NumberFormat::NO_EXPONENT_NOTATION;
        assert!(f64::from_lexical_format(b"+3.0e7", format).is_err());
        assert!(f64::from_lexical_format(b"+3.0e-7", format).is_err());
        assert!(f64::from_lexical_format(b"+3e", format).is_err());
        assert!(f64::from_lexical_format(b"+3e-", format).is_err());
        assert!(f64::from_lexical_format(b"+3.0", format).is_ok());
        assert!(f64::from_lexical_format(b"+3", format).is_ok());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_optional_exponent_test() {
        let format = NumberFormat::permissive().unwrap();
        assert!(f64::from_lexical_format(b"+3.0e7", format).is_ok());
        assert!(f64::from_lexical_format(b"+3.0e-7", format).is_ok());
        assert!(f64::from_lexical_format(b"+3.0e", format).is_ok());
        assert!(f64::from_lexical_format(b"+3.0e-", format).is_ok());
        assert!(f64::from_lexical_format(b"+3.0", format).is_ok());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_required_exponent_test() {
        let format = NumberFormat::REQUIRED_EXPONENT_DIGITS;
        assert!(f64::from_lexical_format(b"+3.0e7", format).is_ok());
        assert!(f64::from_lexical_format(b"+3.0e-7", format).is_ok());
        assert!(f64::from_lexical_format(b"+3.0e", format).is_err());
        assert!(f64::from_lexical_format(b"+3.0e-", format).is_err());
        assert!(f64::from_lexical_format(b"+3.0", format).is_ok());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_no_positive_exponent_sign_test() {
        let format = NumberFormat::NO_POSITIVE_EXPONENT_SIGN;
        assert!(f64::from_lexical_format(b"3.0e7", format).is_ok());
        assert!(f64::from_lexical_format(b"3.0e+7", format).is_err());
        assert!(f64::from_lexical_format(b"3.0e-7", format).is_ok());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_required_exponent_sign_test() {
        let format = NumberFormat::REQUIRED_EXPONENT_SIGN;
        assert!(f64::from_lexical_format(b"3.0e7", format).is_err());
        assert!(f64::from_lexical_format(b"3.0e+7", format).is_ok());
        assert!(f64::from_lexical_format(b"3.0e-7", format).is_ok());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_no_exponent_without_fraction_test() {
        let format = NumberFormat::NO_EXPONENT_WITHOUT_FRACTION;
        assert!(f64::from_lexical_format(b"3.0e7", format).is_ok());
        assert!(f64::from_lexical_format(b"3.e7", format).is_ok());
        assert!(f64::from_lexical_format(b"3e7", format).is_err());

        let format = format | NumberFormat::REQUIRED_FRACTION_DIGITS;
        assert!(f64::from_lexical_format(b"3.0e7", format).is_ok());
        assert!(f64::from_lexical_format(b"3.e7", format).is_err());
        assert!(f64::from_lexical_format(b"3e7", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_no_leading_zeros_test() {
        let format = NumberFormat::NO_FLOAT_LEADING_ZEROS;
        assert!(f64::from_lexical_format(b"1.0", format).is_ok());
        assert!(f64::from_lexical_format(b"0.0", format).is_ok());
        assert!(f64::from_lexical_format(b"01.0", format).is_err());
        assert!(f64::from_lexical_format(b"10.0", format).is_ok());
        assert!(f64::from_lexical_format(b"010.0", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_integer_internal_digit_separator_test() {
        let format = NumberFormat::from_separator(b'_') | NumberFormat::INTEGER_INTERNAL_DIGIT_SEPARATOR;
        assert!(f64::from_lexical_format(b"3_1.0e7", format).is_ok());
        assert!(f64::from_lexical_format(b"_31.0e7", format).is_err());
        assert!(f64::from_lexical_format(b"31_.0e7", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_fraction_internal_digit_separator_test() {
        let format = NumberFormat::from_separator(b'_') | NumberFormat::FRACTION_INTERNAL_DIGIT_SEPARATOR;
        assert!(f64::from_lexical_format(b"31.0_1e7", format).is_ok());
        assert!(f64::from_lexical_format(b"31._01e7", format).is_err());
        assert!(f64::from_lexical_format(b"31.01_e7", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_exponent_internal_digit_separator_test() {
        let format = NumberFormat::from_separator(b'_') | NumberFormat::EXPONENT_INTERNAL_DIGIT_SEPARATOR;
        assert!(f64::from_lexical_format(b"31.01e7_1", format).is_ok());
        assert!(f64::from_lexical_format(b"31.01e_71", format).is_err());
        assert!(f64::from_lexical_format(b"31.01e71_", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_integer_leading_digit_separator_test() {
        let format = NumberFormat::from_separator(b'_') | NumberFormat::INTEGER_LEADING_DIGIT_SEPARATOR;
        assert!(f64::from_lexical_format(b"3_1.0e7", format).is_err());
        assert!(f64::from_lexical_format(b"_31.0e7", format).is_ok());
        assert!(f64::from_lexical_format(b"31_.0e7", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_fraction_leading_digit_separator_test() {
        let format = NumberFormat::from_separator(b'_') | NumberFormat::FRACTION_LEADING_DIGIT_SEPARATOR;
        assert!(f64::from_lexical_format(b"31.0_1e7", format).is_err());
        assert!(f64::from_lexical_format(b"31._01e7", format).is_ok());
        assert!(f64::from_lexical_format(b"31.01_e7", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_exponent_leading_digit_separator_test() {
        let format = NumberFormat::from_separator(b'_') | NumberFormat::EXPONENT_LEADING_DIGIT_SEPARATOR;
        assert!(f64::from_lexical_format(b"31.01e7_1", format).is_err());
        assert!(f64::from_lexical_format(b"31.01e_71", format).is_ok());
        assert!(f64::from_lexical_format(b"31.01e71_", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_integer_trailing_digit_separator_test() {
        let format = NumberFormat::from_separator(b'_') | NumberFormat::INTEGER_TRAILING_DIGIT_SEPARATOR;
        assert!(f64::from_lexical_format(b"3_1.0e7", format).is_err());
        assert!(f64::from_lexical_format(b"_31.0e7", format).is_err());
        assert!(f64::from_lexical_format(b"31_.0e7", format).is_ok());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_fraction_trailing_digit_separator_test() {
        let format = NumberFormat::from_separator(b'_') | NumberFormat::FRACTION_TRAILING_DIGIT_SEPARATOR;
        assert!(f64::from_lexical_format(b"31.0_1e7", format).is_err());
        assert!(f64::from_lexical_format(b"31._01e7", format).is_err());
        assert!(f64::from_lexical_format(b"31.01_e7", format).is_ok());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_exponent_trailing_digit_separator_test() {
        let format = NumberFormat::from_separator(b'_') | NumberFormat::EXPONENT_TRAILING_DIGIT_SEPARATOR;
        assert!(f64::from_lexical_format(b"31.01e7_1", format).is_err());
        assert!(f64::from_lexical_format(b"31.01e_71", format).is_err());
        assert!(f64::from_lexical_format(b"31.01e71_", format).is_ok());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_integer_consecutive_digit_separator_test() {
        let format = NumberFormat::from_separator(b'_')
            | NumberFormat::INTEGER_INTERNAL_DIGIT_SEPARATOR
            | NumberFormat::INTEGER_CONSECUTIVE_DIGIT_SEPARATOR;
        assert!(f64::from_lexical_format(b"3__1.0e7", format).is_ok());
        assert!(f64::from_lexical_format(b"_31.0e7", format).is_err());
        assert!(f64::from_lexical_format(b"31_.0e7", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_fraction_consecutive_digit_separator_test() {
        let format = NumberFormat::from_separator(b'_')
            | NumberFormat::FRACTION_INTERNAL_DIGIT_SEPARATOR
            | NumberFormat::FRACTION_CONSECUTIVE_DIGIT_SEPARATOR;
        assert!(f64::from_lexical_format(b"31.0__1e7", format).is_ok());
        assert!(f64::from_lexical_format(b"31._01e7", format).is_err());
        assert!(f64::from_lexical_format(b"31.01_e7", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_exponent_consecutive_digit_separator_test() {
        let format = NumberFormat::from_separator(b'_')
            | NumberFormat::EXPONENT_INTERNAL_DIGIT_SEPARATOR
            | NumberFormat::EXPONENT_CONSECUTIVE_DIGIT_SEPARATOR;
        assert!(f64::from_lexical_format(b"31.01e7__1", format).is_ok());
        assert!(f64::from_lexical_format(b"31.01e_71", format).is_err());
        assert!(f64::from_lexical_format(b"31.01e71_", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_json_exponent_without_dot() {
        // Tests courtesy of @ijl:
        //  https://github.com/Alexhuszagh/rust-lexical/issues/24#issuecomment-578153783
        let format = NumberFormat::JSON;
        // JSONTestSuite/test_parsing/y_number_0e1.json
        assert!(f64::from_lexical_format(b"0e1", format).is_ok());
        // JSONTestSuite/test_parsing/y_number_int_with_exp.json
        assert!(f64::from_lexical_format(b"20e1", format).is_ok());
        // JSONTestSuite/test_parsing/y_number_real_capital_e_pos_exp.json
        assert!(f64::from_lexical_format(b"1E+2", format).is_ok());
        // JSONTestSuite/test_transform/number_1e-999.json
        assert!(f64::from_lexical_format(b"1E-999", format).is_ok());
        // nativejson-benchmark/data/jsonchecker/pass01.json
        assert!(f64::from_lexical_format(b"23456789012E66", format).is_ok());
    }
    #[test]
    #[cfg(feature = "format")]
    fn f64_json_exponent_requires_digit() {
        // Tests courtesy of @ijl:
        //  https://github.com/Alexhuszagh/rust-lexical/issues/24#issuecomment-578153783
        let format = NumberFormat::JSON;
        assert!(f64::from_lexical_format(b"1e", format).is_err());
        // JSONTestSuite/test_parsing/n_number_9.e+.json
        assert!(f64::from_lexical_format(b"9.e+", format).is_err());
        // JSONTestSuite/test_parsing/n_number_2.e-3.json
        assert!(f64::from_lexical_format(b"2.e-3", format).is_err());
        // JSONTestSuite/test_parsing/n_number_real_without_fractional_part.json
        assert!(f64::from_lexical_format(b"1.", format).is_err());
    }

    #[test]
    #[cfg(feature = "format")]
    fn f64_json_no_leading_zero() {
        let format = NumberFormat::JSON;
        assert!(f64::from_lexical_format(b"12.0", format).is_ok());
        assert!(f64::from_lexical_format(b"-12.0", format).is_ok());
        assert!(f64::from_lexical_format(b"012.0", format).is_err());
        assert!(f64::from_lexical_format(b"-012.0", format).is_err());
    }

    #[cfg(all(feature = "std", feature = "property_tests"))]
    proptest! {
        #[test]
        fn f32_invalid_proptest(i in r"[+-]?[0-9]{2}[^\deE]?\.[^\deE]?[0-9]{2}[^\deE]?e[+-]?[0-9]+[^\deE]") {
            let res = f32::from_lexical(i.as_bytes());
            prop_assert!(res.is_err());
            let err = res.err().unwrap();
            prop_assert_eq!(err.code, ErrorCode::InvalidDigit);
        }

        #[test]
        fn f32_double_sign_proptest(i in r"[+-]{2}[0-9]{2}\.[0-9]{2}e[+-]?[0-9]+") {
            let res = f32::from_lexical(i.as_bytes());
            prop_assert!(res.is_err());
            let err = res.err().unwrap();
            prop_assert!(err.code == ErrorCode::InvalidDigit || err.code == ErrorCode::EmptyMantissa);
            prop_assert!(err.index == 0 || err.index == 1);
        }

        #[test]
        fn f32_sign_or_dot_only_proptest(i in r"[+-]?\.?") {
            let res = f32::from_lexical(i.as_bytes());
            prop_assert!(res.is_err());
            let err = res.err().unwrap();
            prop_assert!(err.code == ErrorCode::Empty || err.code == ErrorCode::EmptyMantissa);
            prop_assert!(err.index == 0 || err.index == 1);
        }

        #[test]
        fn f32_double_exponent_sign_proptest(i in r"[+-]?[0-9]{2}\.[0-9]{2}e[+-]{2}[0-9]+") {
            let res = f32::from_lexical(i.as_bytes());
            prop_assert!(res.is_err());
            let err = res.err().unwrap();
            prop_assert_eq!(err.code, ErrorCode::EmptyExponent);
        }

        #[test]
        fn f32_missing_exponent_proptest(i in r"[+-]?[0-9]{2}\.[0-9]{2}e[+-]?") {
            let res = f32::from_lexical(i.as_bytes());
            prop_assert!(res.is_err());
            let err = res.err().unwrap();
            prop_assert_eq!(err.code, ErrorCode::EmptyExponent);
        }

        #[cfg(feature = "correct")]
        #[test]
        fn f32_roundtrip_display_proptest(i in f32::MIN..f32::MAX) {
            let input: String = format!("{}", i);
            prop_assert_eq!(i, f32::from_lexical(input.as_bytes()).unwrap());
        }

        #[cfg(feature = "correct")]
        #[test]
        fn f32_roundtrip_debug_proptest(i in f32::MIN..f32::MAX) {
            let input: String = format!("{:?}", i);
            prop_assert_eq!(i, f32::from_lexical(input.as_bytes()).unwrap());
        }

        #[cfg(feature = "correct")]
        #[test]
        fn f32_roundtrip_scientific_proptest(i in f32::MIN..f32::MAX) {
            let input: String = format!("{:e}", i);
            prop_assert_eq!(i, f32::from_lexical(input.as_bytes()).unwrap());
        }

        #[test]
        fn f64_invalid_proptest(i in r"[+-]?[0-9]{2}[^\deE]?\.[^\deE]?[0-9]{2}[^\deE]?e[+-]?[0-9]+[^\deE]") {
            let res = f64::from_lexical(i.as_bytes());
            prop_assert!(res.is_err());
            let err = res.err().unwrap();
            prop_assert_eq!(err.code, ErrorCode::InvalidDigit);
        }

        #[test]
        fn f64_double_sign_proptest(i in r"[+-]{2}[0-9]{2}\.[0-9]{2}e[+-]?[0-9]+") {
            let res = f64::from_lexical(i.as_bytes());
            prop_assert!(res.is_err());
            let err = res.err().unwrap();
            prop_assert!(err.code == ErrorCode::InvalidDigit || err.code == ErrorCode::EmptyMantissa);
            prop_assert!(err.index == 0 || err.index == 1);
        }

        #[test]
        fn f64_sign_or_dot_only_proptest(i in r"[+-]?\.?") {
            let res = f64::from_lexical(i.as_bytes());
            prop_assert!(res.is_err());
            let err = res.err().unwrap();
            prop_assert!(err.code == ErrorCode::Empty || err.code == ErrorCode::EmptyMantissa);
            prop_assert!(err.index == 0 || err.index == 1);
        }

        #[test]
        fn f64_double_exponent_sign_proptest(i in r"[+-]?[0-9]{2}\.[0-9]{2}e[+-]{2}[0-9]+") {
            let res = f64::from_lexical(i.as_bytes());
            prop_assert!(res.is_err());
            let err = res.err().unwrap();
            prop_assert_eq!(err.code, ErrorCode::EmptyExponent);
        }

        #[test]
        fn f64_missing_exponent_proptest(i in r"[+-]?[0-9]{2}\.[0-9]{2}e[+-]?") {
            let res = f64::from_lexical(i.as_bytes());
            prop_assert!(res.is_err());
            let err = res.err().unwrap();
            prop_assert_eq!(err.code, ErrorCode::EmptyExponent);
        }

        #[cfg(feature = "correct")]
        #[test]
        fn f64_roundtrip_display_proptest(i in f64::MIN..f64::MAX) {
            let input: String = format!("{}", i);
            prop_assert_eq!(i, f64::from_lexical(input.as_bytes()).unwrap());
        }

        #[cfg(feature = "correct")]
        #[test]
        fn f64_roundtrip_debug_proptest(i in f64::MIN..f64::MAX) {
            let input: String = format!("{:?}", i);
            prop_assert_eq!(i, f64::from_lexical(input.as_bytes()).unwrap());
        }

        #[cfg(feature = "correct")]
        #[test]
        fn f64_roundtrip_scientific_proptest(i in f64::MIN..f64::MAX) {
            let input: String = format!("{:e}", i);
            prop_assert_eq!(i, f64::from_lexical(input.as_bytes()).unwrap());
        }
    }
}