diff options
Diffstat (limited to 'src/libcore/num/float_macros.rs')
| -rw-r--r-- | src/libcore/num/float_macros.rs | 141 |
1 files changed, 0 insertions, 141 deletions
diff --git a/src/libcore/num/float_macros.rs b/src/libcore/num/float_macros.rs index 88c3b756793..b3adef53dab 100644 --- a/src/libcore/num/float_macros.rs +++ b/src/libcore/num/float_macros.rs @@ -18,144 +18,3 @@ macro_rules! assert_approx_eq { "{} is not approximately equal to {}", *a, *b); }) } - -macro_rules! from_str_radix_float_impl { - ($T:ty) => { - fn from_str_radix(src: &str, radix: u32) - -> Result<$T, ParseFloatError> { - use num::dec2flt::{pfe_empty, pfe_invalid}; - - // Special values - match src { - "inf" => return Ok(Float::infinity()), - "-inf" => return Ok(Float::neg_infinity()), - "NaN" => return Ok(Float::nan()), - _ => {}, - } - - let (is_positive, src) = match src.slice_shift_char() { - None => return Err(pfe_empty()), - Some(('-', "")) => return Err(pfe_empty()), - Some(('-', src)) => (false, src), - Some((_, _)) => (true, src), - }; - - // The significand to accumulate - let mut sig = if is_positive { 0.0 } else { -0.0 }; - // Necessary to detect overflow - let mut prev_sig = sig; - let mut cs = src.chars().enumerate(); - // Exponent prefix and exponent index offset - let mut exp_info = None::<(char, usize)>; - - // Parse the integer part of the significand - for (i, c) in cs.by_ref() { - match c.to_digit(radix) { - Some(digit) => { - // shift significand one digit left - sig = sig * (radix as $T); - - // add/subtract current digit depending on sign - if is_positive { - sig = sig + ((digit as isize) as $T); - } else { - sig = sig - ((digit as isize) as $T); - } - - // Detect overflow by comparing to last value, except - // if we've not seen any non-zero digits. - if prev_sig != 0.0 { - if is_positive && sig <= prev_sig - { return Ok(Float::infinity()); } - if !is_positive && sig >= prev_sig - { return Ok(Float::neg_infinity()); } - - // Detect overflow by reversing the shift-and-add process - if is_positive && (prev_sig != (sig - digit as $T) / radix as $T) - { return Ok(Float::infinity()); } - if !is_positive && (prev_sig != (sig + digit as $T) / radix as $T) - { return Ok(Float::neg_infinity()); } - } - prev_sig = sig; - }, - None => match c { - 'e' | 'E' | 'p' | 'P' => { - exp_info = Some((c, i + 1)); - break; // start of exponent - }, - '.' => { - break; // start of fractional part - }, - _ => { - return Err(pfe_invalid()) - }, - }, - } - } - - // If we are not yet at the exponent parse the fractional - // part of the significand - if exp_info.is_none() { - let mut power = 1.0; - for (i, c) in cs.by_ref() { - match c.to_digit(radix) { - Some(digit) => { - // Decrease power one order of magnitude - power = power / (radix as $T); - // add/subtract current digit depending on sign - sig = if is_positive { - sig + (digit as $T) * power - } else { - sig - (digit as $T) * power - }; - // Detect overflow by comparing to last value - if is_positive && sig < prev_sig - { return Ok(Float::infinity()); } - if !is_positive && sig > prev_sig - { return Ok(Float::neg_infinity()); } - prev_sig = sig; - }, - None => match c { - 'e' | 'E' | 'p' | 'P' => { - exp_info = Some((c, i + 1)); - break; // start of exponent - }, - _ => { - return Err(pfe_invalid()) - }, - }, - } - } - } - - // Parse and calculate the exponent - let exp = match exp_info { - Some((c, offset)) => { - let base = match c { - 'E' | 'e' if radix == 10 => 10.0, - 'P' | 'p' if radix == 16 => 2.0, - _ => return Err(pfe_invalid()), - }; - - // Parse the exponent as decimal integer - let src = &src[offset..]; - let (is_positive, exp) = match src.slice_shift_char() { - Some(('-', src)) => (false, src.parse::<usize>()), - Some(('+', src)) => (true, src.parse::<usize>()), - Some((_, _)) => (true, src.parse::<usize>()), - None => return Err(pfe_invalid()), - }; - - match (is_positive, exp) { - (true, Ok(exp)) => base.powi(exp as i32), - (false, Ok(exp)) => 1.0 / base.powi(exp as i32), - (_, Err(_)) => return Err(pfe_invalid()), - } - }, - None => 1.0, // no exponent - }; - - Ok(sig * exp) - } - } -} |