squiid/rust
1
0
Fork 0
Code Issues Pull requests Projects Activity

core: Shuffle around float parsing

Browse source 
Stop using stability to hide the implementation details of ParseFloatError and
instead move the error type into the `dec2flt` module. Also move the
implementation blocks of `FromStr for f{32,64}` into `dec2flt` directly.
This commit is contained in:
Alex Crichton 2015-08-17 14:16:41 -07:00
parent 5990249e48
commit a2b932c0b6
9 changed files with 133 additions and 138 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

100
src/libcore/num/dec2flt/mod.rs
View file

@ -96,8 +96,9 @@
issue = "0")]
use prelude::v1::*;
use num::ParseFloatError as PFE;
use num::FloatErrorKind;
use fmt;
use str::FromStr;
use self::parse::{parse_decimal, Decimal, Sign};
use self::parse::ParseResult::{self, Valid, ShortcutToInf, ShortcutToZero};
use self::num::digits_to_big;
@ -110,14 +111,87 @@ mod num;
pub mod rawfp;
pub mod parse;
/// Entry point for decimal-to-f32 conversion.
pub fn to_f32(s: &str) -> Result<f32, PFE> {
dec2flt(s)
macro_rules! from_str_float_impl {
($t:ty, $func:ident) => {
#[stable(feature = "rust1", since = "1.0.0")]
impl FromStr for $t {
type Err = ParseFloatError;
/// Converts a string in base 10 to a float.
/// Accepts an optional decimal exponent.
///
/// This function accepts strings such as
///
/// * '3.14'
/// * '-3.14'
/// * '2.5E10', or equivalently, '2.5e10'
/// * '2.5E-10'
/// * '.' (understood as 0)
/// * '5.'
/// * '.5', or, equivalently, '0.5'
/// * 'inf', '-inf', 'NaN'
///
/// Leading and trailing whitespace represent an error.
///
/// # Arguments
///
/// * src - A string
///
/// # Return value
///
/// `Err(ParseFloatError)` if the string did not represent a valid
/// number. Otherwise, `Ok(n)` where `n` is the floating-point
/// number represented by `src`.
#[inline]
fn from_str(src: &str) -> Result<Self, ParseFloatError> {
dec2flt(src)
}
}
}
}
from_str_float_impl!(f32, to_f32);
from_str_float_impl!(f64, to_f64);
/// An error which can be returned when parsing a float.
#[derive(Debug, Clone, PartialEq)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct ParseFloatError {
kind: FloatErrorKind
}
/// Entry point for decimal-to-f64 conversion.
pub fn to_f64(s: &str) -> Result<f64, PFE> {
dec2flt(s)
#[derive(Debug, Clone, PartialEq)]
enum FloatErrorKind {
Empty,
Invalid,
}
impl ParseFloatError {
#[unstable(feature = "int_error_internals",
reason = "available through Error trait and this method should \
not be exposed publicly",
issue = "0")]
#[doc(hidden)]
pub fn __description(&self) -> &str {
match self.kind {
FloatErrorKind::Empty => "cannot parse float from empty string",
FloatErrorKind::Invalid => "invalid float literal",
}
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Display for ParseFloatError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
self.__description().fmt(f)
}
}
pub fn pfe_empty() -> ParseFloatError {
ParseFloatError { kind: FloatErrorKind::Empty }
}
pub fn pfe_invalid() -> ParseFloatError {
ParseFloatError { kind: FloatErrorKind::Invalid }
}
/// Split decimal string into sign and the rest, without inspecting or validating the rest.
@ -131,9 +205,9 @@ fn extract_sign(s: &str) -> (Sign, &str) {
}
/// Convert a decimal string into a floating point number.
fn dec2flt<T: RawFloat>(s: &str) -> Result<T, PFE> {
fn dec2flt<T: RawFloat>(s: &str) -> Result<T, ParseFloatError> {
if s.is_empty() {
return Err(PFE { __kind: FloatErrorKind::Empty });
return Err(pfe_empty())
}
let (sign, s) = extract_sign(s);
let flt = match parse_decimal(s) {
@ -143,7 +217,7 @@ fn dec2flt<T: RawFloat>(s: &str) -> Result<T, PFE> {
ParseResult::Invalid => match s {
"inf" => T::infinity(),
"NaN" => T::nan(),
_ => { return Err(PFE { __kind: FloatErrorKind::Invalid }); }
_ => { return Err(pfe_invalid()); }
}
};
@ -155,7 +229,7 @@ fn dec2flt<T: RawFloat>(s: &str) -> Result<T, PFE> {
/// The main workhorse for the decimal-to-float conversion: Orchestrate all the preprocessing
/// and figure out which algorithm should do the actual conversion.
fn convert<T: RawFloat>(mut decimal: Decimal) -> Result<T, PFE> {
fn convert<T: RawFloat>(mut decimal: Decimal) -> Result<T, ParseFloatError> {
simplify(&mut decimal);
if let Some(x) = trivial_cases(&decimal) {
return Ok(x);
@ -172,7 +246,7 @@ fn convert<T: RawFloat>(mut decimal: Decimal) -> Result<T, PFE> {
// If we exceed this, perhaps while calculating `f * 10^e` in Algorithm R or Algorithm M,
// we'll crash. So we error out before getting too close, with a generous safety margin.
if max_digits > 375 {
return Err(PFE { __kind: FloatErrorKind::Invalid });
return Err(pfe_invalid());
}
let f = digits_to_big(decimal.integral, decimal.fractional);

17
src/libcore/num/float_macros.rs
View file

@ -23,8 +23,7 @@ macro_rules! from_str_radix_float_impl {
($T:ty) => {
fn from_str_radix(src: &str, radix: u32)
-> Result<$T, ParseFloatError> {
use num::FloatErrorKind::*;
use num::ParseFloatError as PFE;
use num::dec2flt::{pfe_empty, pfe_invalid};
// Special values
match src {
@ -35,8 +34,8 @@ macro_rules! from_str_radix_float_impl {
}
let (is_positive, src) = match src.slice_shift_char() {
None => return Err(PFE { __kind: Empty }),
Some(('-', "")) => return Err(PFE { __kind: Empty }),
None => return Err(pfe_empty()),
Some(('-', "")) => return Err(pfe_empty()),
Some(('-', src)) => (false, src),
Some((_, _)) => (true, src),
};
@ -88,7 +87,7 @@ macro_rules! from_str_radix_float_impl {
break; // start of fractional part
},
_ => {
return Err(PFE { __kind: Invalid });
return Err(pfe_invalid())
},
},
}
@ -122,7 +121,7 @@ macro_rules! from_str_radix_float_impl {
break; // start of exponent
},
_ => {
return Err(PFE { __kind: Invalid });
return Err(pfe_invalid())
},
},
}
@ -135,7 +134,7 @@ macro_rules! from_str_radix_float_impl {
let base = match c {
'E' | 'e' if radix == 10 => 10.0,
'P' | 'p' if radix == 16 => 2.0,
_ => return Err(PFE { __kind: Invalid }),
_ => return Err(pfe_invalid()),
};
// Parse the exponent as decimal integer
@ -144,13 +143,13 @@ macro_rules! from_str_radix_float_impl {
Some(('-', src)) => (false, src.parse::<usize>()),
Some(('+', src)) => (true, src.parse::<usize>()),
Some((_, _)) => (true, src.parse::<usize>()),
None => return Err(PFE { __kind: Invalid }),
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 { __kind: Invalid }),
(_, Err(_)) => return Err(pfe_invalid()),
}
},
None => 1.0, // no exponent

79
src/libcore/num/mod.rs
View file

@ -1365,47 +1365,6 @@ pub trait Float: Sized {
fn to_radians(self) -> Self;
}
macro_rules! from_str_float_impl {
($t:ty, $func:ident) => {
#[stable(feature = "rust1", since = "1.0.0")]
impl FromStr for $t {
type Err = ParseFloatError;
/// Converts a string in base 10 to a float.
/// Accepts an optional decimal exponent.
///
/// This function accepts strings such as
///
/// * '3.14'
/// * '-3.14'
/// * '2.5E10', or equivalently, '2.5e10'
/// * '2.5E-10'
/// * '.' (understood as 0)
/// * '5.'
/// * '.5', or, equivalently, '0.5'
/// * 'inf', '-inf', 'NaN'
///
/// Leading and trailing whitespace represent an error.
///
/// # Arguments
///
/// * src - A string
///
/// # Return value
///
/// `Err(ParseFloatError)` if the string did not represent a valid
/// number. Otherwise, `Ok(n)` where `n` is the floating-point
/// number represented by `src`.
#[inline]
fn from_str(src: &str) -> Result<Self, ParseFloatError> {
dec2flt::$func(src)
}
}
}
}
from_str_float_impl!(f32, to_f32);
from_str_float_impl!(f64, to_f64);
macro_rules! from_str_radix_int_impl {
($($t:ty)*) => {$(
#[stable(feature = "rust1", since = "1.0.0")]
@ -1548,40 +1507,4 @@ impl fmt::Display for ParseIntError {
}
}
/// An error which can be returned when parsing a float.
#[derive(Debug, Clone, PartialEq)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct ParseFloatError {
#[doc(hidden)]
#[unstable(feature = "float_error_internals",
reason = "should not be exposed publicly",
issue = "0")]
pub __kind: FloatErrorKind
}
#[derive(Debug, Clone, PartialEq)]
#[unstable(feature = "float_error_internals",
reason = "should not be exposed publicly",
issue = "0")]
#[doc(hidden)]
pub enum FloatErrorKind {
Empty,
Invalid,
}
impl ParseFloatError {
#[doc(hidden)]
pub fn __description(&self) -> &str {
match self.__kind {
FloatErrorKind::Empty => "cannot parse float from empty string",
FloatErrorKind::Invalid => "invalid float literal",
}
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Display for ParseFloatError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
self.__description().fmt(f)
}
}
pub use num::dec2flt::ParseFloatError;

4
src/libcoretest/atomic.rs
View file

@ -8,8 +8,8 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use core::atomic::*;
use core::atomic::Ordering::SeqCst;
use core::sync::atomic::*;
use core::sync::atomic::Ordering::SeqCst;
#[test]
fn bool_() {

51
src/libcoretest/num/dec2flt/mod.rs
View file

@ -12,7 +12,6 @@
use std::{i64, f32, f64};
use test;
use core::num::dec2flt::{to_f32, to_f64};
mod parse;
mod rawfp;
@ -27,11 +26,11 @@ macro_rules! test_literal {
let inputs = &[stringify!($x).into(), format!("{:?}", x64), format!("{:e}", x64)];
for input in inputs {
if input != "inf" {
assert_eq!(to_f64(input), Ok(x64));
assert_eq!(to_f32(input), Ok(x32));
assert_eq!(input.parse(), Ok(x64));
assert_eq!(input.parse(), Ok(x32));
let neg_input = &format!("-{}", input);
assert_eq!(to_f64(neg_input), Ok(-x64));
assert_eq!(to_f32(neg_input), Ok(-x32));
assert_eq!(neg_input.parse(), Ok(-x64));
assert_eq!(neg_input.parse(), Ok(-x32));
}
}
})
@ -99,83 +98,83 @@ fn fast_path_correct() {
#[test]
fn lonely_dot() {
assert_eq!(to_f64("."), Ok(0.0));
assert_eq!(".".parse(), Ok(0.0));
}
#[test]
fn nan() {
assert!(to_f64("NaN").unwrap().is_nan());
assert!(to_f32("NaN").unwrap().is_nan());
assert!("NaN".parse::<f32>().unwrap().is_nan());
assert!("NaN".parse::<f64>().unwrap().is_nan());
}
#[test]
fn inf() {
assert_eq!(to_f64("inf"), Ok(f64::INFINITY));
assert_eq!(to_f64("-inf"), Ok(f64::NEG_INFINITY));
assert_eq!(to_f32("inf"), Ok(f32::INFINITY));
assert_eq!(to_f32("-inf"), Ok(f32::NEG_INFINITY));
assert_eq!("inf".parse(), Ok(f64::INFINITY));
assert_eq!("-inf".parse(), Ok(f64::NEG_INFINITY));
assert_eq!("inf".parse(), Ok(f32::INFINITY));
assert_eq!("-inf".parse(), Ok(f32::NEG_INFINITY));
}
#[test]
fn massive_exponent() {
let max = i64::MAX;
assert_eq!(to_f64(&format!("1e{}000", max)), Ok(f64::INFINITY));
assert_eq!(to_f64(&format!("1e-{}000", max)), Ok(0.0));
assert_eq!(to_f64(&format!("1e{}000", max)), Ok(f64::INFINITY));
assert_eq!(format!("1e{}000", max).parse(), Ok(f64::INFINITY));
assert_eq!(format!("1e-{}000", max).parse(), Ok(0.0));
assert_eq!(format!("1e{}000", max).parse(), Ok(f64::INFINITY));
}
#[bench]
fn bench_0(b: &mut test::Bencher) {
b.iter(|| to_f64("0.0"));
b.iter(|| "0.0".parse::<f64>());
}
#[bench]
fn bench_42(b: &mut test::Bencher) {
b.iter(|| to_f64("42"));
b.iter(|| "42".parse::<f64>());
}
#[bench]
fn bench_huge_int(b: &mut test::Bencher) {
// 2^128 - 1
b.iter(|| to_f64("170141183460469231731687303715884105727"));
b.iter(|| "170141183460469231731687303715884105727".parse::<f64>());
}
#[bench]
fn bench_short_decimal(b: &mut test::Bencher) {
b.iter(|| to_f64("1234.5678"));
b.iter(|| "1234.5678".parse::<f64>());
}
#[bench]
fn bench_pi_long(b: &mut test::Bencher) {
b.iter(|| to_f64("3.14159265358979323846264338327950288"));
b.iter(|| "3.14159265358979323846264338327950288".parse::<f64>());
}
#[bench]
fn bench_pi_short(b: &mut test::Bencher) {
b.iter(|| to_f64("3.141592653589793"))
b.iter(|| "3.141592653589793".parse::<f64>())
}
#[bench]
fn bench_1e150(b: &mut test::Bencher) {
b.iter(|| to_f64("1e150"));
b.iter(|| "1e150".parse::<f64>());
}
#[bench]
fn bench_long_decimal_and_exp(b: &mut test::Bencher) {
b.iter(|| to_f64("727501488517303786137132964064381141071e-123"));
b.iter(|| "727501488517303786137132964064381141071e-123".parse::<f64>());
}
#[bench]
fn bench_min_subnormal(b: &mut test::Bencher) {
b.iter(|| to_f64("5e-324"));
b.iter(|| "5e-324".parse::<f64>());
}
#[bench]
fn bench_min_normal(b: &mut test::Bencher) {
b.iter(|| to_f64("2.2250738585072014e-308"));
b.iter(|| "2.2250738585072014e-308".parse::<f64>());
}
#[bench]
fn bench_max(b: &mut test::Bencher) {
b.iter(|| to_f64("1.7976931348623157e308"));
b.iter(|| "1.7976931348623157e308".parse::<f64>());
}

4
src/libcoretest/num/uint_macros.rs
View file

@ -14,7 +14,7 @@ mod tests {
use core::$T_i::*;
use num;
use core::ops::{BitOr, BitAnd, BitXor, Shl, Shr, Not};
use std::str;
use std::str::FromStr;
#[test]
fn test_overflows() {
@ -152,5 +152,5 @@ mod tests {
assert_eq!($T::from_str_radix("Z", 10).ok(), None::<$T>);
assert_eq!($T::from_str_radix("_", 2).ok(), None::<$T>);
}
}
)}

4
src/test/compile-fail/issue-1920-1.rs
View file

@ -17,6 +17,6 @@ mod foo {
fn assert_clone<T>() where T : Clone { }
fn main() {
assert_clone::<foo::core::atomic::AtomicBool>();
assert_clone::<foo::core::sync::atomic::AtomicBool>();
//~^ ERROR the trait `foo::core::clone::Clone` is not implemented for the type `foo::core::
}
}

6
src/test/compile-fail/issue-1920-2.rs
View file

@ -15,6 +15,6 @@ extern crate core as bar;
fn assert_clone<T>() where T : Clone { }
fn main() {
assert_clone::<bar::atomic::AtomicBool>();
//~^ ERROR the trait `bar::clone::Clone` is not implemented for the type `bar::atomic::
}
assert_clone::<bar::sync::atomic::AtomicBool>();
//~^ ERROR the trait `bar::clone::Clone` is not implemented for the type `bar::sync::atomic::
}

6
src/test/compile-fail/issue-1920-3.rs
View file

@ -19,6 +19,6 @@ extern crate core;
fn assert_clone<T>() where T : Clone { }
fn main() {
assert_clone::<foo::core::atomic::AtomicBool>();
//~^ ERROR the trait `core::clone::Clone` is not implemented for the type `core::atomic::
}
assert_clone::<foo::core::sync::atomic::AtomicBool>();
//~^ ERROR the trait `core::clone::Clone` is not implemented for the type `core::sync::atomic::
}