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author | Valentin Popov <valentin@popov.link> | 2024-01-08 00:21:28 +0300 |
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committer | Valentin Popov <valentin@popov.link> | 2024-01-08 00:21:28 +0300 |
commit | 1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch) | |
tree | 7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/ryu/src/pretty/mod.rs | |
parent | 5ecd8cf2cba827454317368b68571df0d13d7842 (diff) | |
download | fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip |
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/ryu/src/pretty/mod.rs')
-rw-r--r-- | vendor/ryu/src/pretty/mod.rs | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/vendor/ryu/src/pretty/mod.rs b/vendor/ryu/src/pretty/mod.rs new file mode 100644 index 0000000..da49e86 --- /dev/null +++ b/vendor/ryu/src/pretty/mod.rs @@ -0,0 +1,224 @@ +mod exponent; +mod mantissa; + +use self::exponent::*; +use self::mantissa::*; +use crate::common; +use crate::d2s::{self, *}; +use crate::f2s::*; +use core::ptr; +#[cfg(feature = "no-panic")] +use no_panic::no_panic; + +/// Print f64 to the given buffer and return number of bytes written. +/// +/// At most 24 bytes will be written. +/// +/// ## Special cases +/// +/// This function **does not** check for NaN or infinity. If the input +/// number is not a finite float, the printed representation will be some +/// correctly formatted but unspecified numerical value. +/// +/// Please check [`is_finite`] yourself before calling this function, or +/// check [`is_nan`] and [`is_infinite`] and handle those cases yourself. +/// +/// [`is_finite`]: https://doc.rust-lang.org/std/primitive.f64.html#method.is_finite +/// [`is_nan`]: https://doc.rust-lang.org/std/primitive.f64.html#method.is_nan +/// [`is_infinite`]: https://doc.rust-lang.org/std/primitive.f64.html#method.is_infinite +/// +/// ## Safety +/// +/// The `result` pointer argument must point to sufficiently many writable bytes +/// to hold Ryū's representation of `f`. +/// +/// ## Example +/// +/// ``` +/// use std::{mem::MaybeUninit, slice, str}; +/// +/// let f = 1.234f64; +/// +/// unsafe { +/// let mut buffer = [MaybeUninit::<u8>::uninit(); 24]; +/// let len = ryu::raw::format64(f, buffer.as_mut_ptr() as *mut u8); +/// let slice = slice::from_raw_parts(buffer.as_ptr() as *const u8, len); +/// let print = str::from_utf8_unchecked(slice); +/// assert_eq!(print, "1.234"); +/// } +/// ``` +#[must_use] +#[cfg_attr(feature = "no-panic", no_panic)] +pub unsafe fn format64(f: f64, result: *mut u8) -> usize { + let bits = f.to_bits(); + let sign = ((bits >> (DOUBLE_MANTISSA_BITS + DOUBLE_EXPONENT_BITS)) & 1) != 0; + let ieee_mantissa = bits & ((1u64 << DOUBLE_MANTISSA_BITS) - 1); + let ieee_exponent = + (bits >> DOUBLE_MANTISSA_BITS) as u32 & ((1u32 << DOUBLE_EXPONENT_BITS) - 1); + + let mut index = 0isize; + if sign { + *result = b'-'; + index += 1; + } + + if ieee_exponent == 0 && ieee_mantissa == 0 { + ptr::copy_nonoverlapping(b"0.0".as_ptr(), result.offset(index), 3); + return sign as usize + 3; + } + + let v = d2d(ieee_mantissa, ieee_exponent); + + let length = d2s::decimal_length17(v.mantissa) as isize; + let k = v.exponent as isize; + let kk = length + k; // 10^(kk-1) <= v < 10^kk + debug_assert!(k >= -324); + + if 0 <= k && kk <= 16 { + // 1234e7 -> 12340000000.0 + write_mantissa_long(v.mantissa, result.offset(index + length)); + for i in length..kk { + *result.offset(index + i) = b'0'; + } + *result.offset(index + kk) = b'.'; + *result.offset(index + kk + 1) = b'0'; + index as usize + kk as usize + 2 + } else if 0 < kk && kk <= 16 { + // 1234e-2 -> 12.34 + write_mantissa_long(v.mantissa, result.offset(index + length + 1)); + ptr::copy(result.offset(index + 1), result.offset(index), kk as usize); + *result.offset(index + kk) = b'.'; + index as usize + length as usize + 1 + } else if -5 < kk && kk <= 0 { + // 1234e-6 -> 0.001234 + *result.offset(index) = b'0'; + *result.offset(index + 1) = b'.'; + let offset = 2 - kk; + for i in 2..offset { + *result.offset(index + i) = b'0'; + } + write_mantissa_long(v.mantissa, result.offset(index + length + offset)); + index as usize + length as usize + offset as usize + } else if length == 1 { + // 1e30 + *result.offset(index) = b'0' + v.mantissa as u8; + *result.offset(index + 1) = b'e'; + index as usize + 2 + write_exponent3(kk - 1, result.offset(index + 2)) + } else { + // 1234e30 -> 1.234e33 + write_mantissa_long(v.mantissa, result.offset(index + length + 1)); + *result.offset(index) = *result.offset(index + 1); + *result.offset(index + 1) = b'.'; + *result.offset(index + length + 1) = b'e'; + index as usize + + length as usize + + 2 + + write_exponent3(kk - 1, result.offset(index + length + 2)) + } +} + +/// Print f32 to the given buffer and return number of bytes written. +/// +/// At most 16 bytes will be written. +/// +/// ## Special cases +/// +/// This function **does not** check for NaN or infinity. If the input +/// number is not a finite float, the printed representation will be some +/// correctly formatted but unspecified numerical value. +/// +/// Please check [`is_finite`] yourself before calling this function, or +/// check [`is_nan`] and [`is_infinite`] and handle those cases yourself. +/// +/// [`is_finite`]: https://doc.rust-lang.org/std/primitive.f32.html#method.is_finite +/// [`is_nan`]: https://doc.rust-lang.org/std/primitive.f32.html#method.is_nan +/// [`is_infinite`]: https://doc.rust-lang.org/std/primitive.f32.html#method.is_infinite +/// +/// ## Safety +/// +/// The `result` pointer argument must point to sufficiently many writable bytes +/// to hold Ryū's representation of `f`. +/// +/// ## Example +/// +/// ``` +/// use std::{mem::MaybeUninit, slice, str}; +/// +/// let f = 1.234f32; +/// +/// unsafe { +/// let mut buffer = [MaybeUninit::<u8>::uninit(); 16]; +/// let len = ryu::raw::format32(f, buffer.as_mut_ptr() as *mut u8); +/// let slice = slice::from_raw_parts(buffer.as_ptr() as *const u8, len); +/// let print = str::from_utf8_unchecked(slice); +/// assert_eq!(print, "1.234"); +/// } +/// ``` +#[must_use] +#[cfg_attr(feature = "no-panic", no_panic)] +pub unsafe fn format32(f: f32, result: *mut u8) -> usize { + let bits = f.to_bits(); + let sign = ((bits >> (FLOAT_MANTISSA_BITS + FLOAT_EXPONENT_BITS)) & 1) != 0; + let ieee_mantissa = bits & ((1u32 << FLOAT_MANTISSA_BITS) - 1); + let ieee_exponent = (bits >> FLOAT_MANTISSA_BITS) & ((1u32 << FLOAT_EXPONENT_BITS) - 1); + + let mut index = 0isize; + if sign { + *result = b'-'; + index += 1; + } + + if ieee_exponent == 0 && ieee_mantissa == 0 { + ptr::copy_nonoverlapping(b"0.0".as_ptr(), result.offset(index), 3); + return sign as usize + 3; + } + + let v = f2d(ieee_mantissa, ieee_exponent); + + let length = common::decimal_length9(v.mantissa) as isize; + let k = v.exponent as isize; + let kk = length + k; // 10^(kk-1) <= v < 10^kk + debug_assert!(k >= -45); + + if 0 <= k && kk <= 13 { + // 1234e7 -> 12340000000.0 + write_mantissa(v.mantissa, result.offset(index + length)); + for i in length..kk { + *result.offset(index + i) = b'0'; + } + *result.offset(index + kk) = b'.'; + *result.offset(index + kk + 1) = b'0'; + index as usize + kk as usize + 2 + } else if 0 < kk && kk <= 13 { + // 1234e-2 -> 12.34 + write_mantissa(v.mantissa, result.offset(index + length + 1)); + ptr::copy(result.offset(index + 1), result.offset(index), kk as usize); + *result.offset(index + kk) = b'.'; + index as usize + length as usize + 1 + } else if -6 < kk && kk <= 0 { + // 1234e-6 -> 0.001234 + *result.offset(index) = b'0'; + *result.offset(index + 1) = b'.'; + let offset = 2 - kk; + for i in 2..offset { + *result.offset(index + i) = b'0'; + } + write_mantissa(v.mantissa, result.offset(index + length + offset)); + index as usize + length as usize + offset as usize + } else if length == 1 { + // 1e30 + *result.offset(index) = b'0' + v.mantissa as u8; + *result.offset(index + 1) = b'e'; + index as usize + 2 + write_exponent2(kk - 1, result.offset(index + 2)) + } else { + // 1234e30 -> 1.234e33 + write_mantissa(v.mantissa, result.offset(index + length + 1)); + *result.offset(index) = *result.offset(index + 1); + *result.offset(index + 1) = b'.'; + *result.offset(index + length + 1) = b'e'; + index as usize + + length as usize + + 2 + + write_exponent2(kk - 1, result.offset(index + length + 2)) + } +} |