// Copyright 2012 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. //! Operations and constants for `float` // Even though this module exports everything defined in it, // because it contains re-exports, we also have to explicitly // export locally defined things. That's a bit annoying. // export when m_float == c_double // PORT this must match in width according to architecture use m_float = f64; use cmp::{Eq, Ord}; use cmp; use f64; use num; use num::NumCast; use option::{None, Option, Some}; use str; use uint; use to_str; use from_str; pub use f64::{add, sub, mul, div, rem, lt, le, eq, ne, ge, gt}; pub use f64::logarithm; pub use f64::{acos, asin, atan2, cbrt, ceil, copysign, cosh, floor}; pub use f64::{erf, erfc, exp, expm1, exp2, abs_sub}; pub use f64::{mul_add, fmax, fmin, nextafter, frexp, hypot, ldexp}; pub use f64::{lgamma, ln, log_radix, ln1p, log10, log2, ilog_radix}; pub use f64::{modf, pow, round, sinh, tanh, tgamma, trunc}; pub use f64::signbit; pub use f64::{j0, j1, jn, y0, y1, yn}; pub const NaN: float = 0.0/0.0; pub const infinity: float = 1.0/0.0; pub const neg_infinity: float = -1.0/0.0; /* Module: consts */ pub mod consts { // FIXME (requires Issue #1433 to fix): replace with mathematical // constants from cmath. /// Archimedes' constant pub const pi: float = 3.14159265358979323846264338327950288; /// pi/2.0 pub const frac_pi_2: float = 1.57079632679489661923132169163975144; /// pi/4.0 pub const frac_pi_4: float = 0.785398163397448309615660845819875721; /// 1.0/pi pub const frac_1_pi: float = 0.318309886183790671537767526745028724; /// 2.0/pi pub const frac_2_pi: float = 0.636619772367581343075535053490057448; /// 2.0/sqrt(pi) pub const frac_2_sqrtpi: float = 1.12837916709551257389615890312154517; /// sqrt(2.0) pub const sqrt2: float = 1.41421356237309504880168872420969808; /// 1.0/sqrt(2.0) pub const frac_1_sqrt2: float = 0.707106781186547524400844362104849039; /// Euler's number pub const e: float = 2.71828182845904523536028747135266250; /// log2(e) pub const log2_e: float = 1.44269504088896340735992468100189214; /// log10(e) pub const log10_e: float = 0.434294481903251827651128918916605082; /// ln(2.0) pub const ln_2: float = 0.693147180559945309417232121458176568; /// ln(10.0) pub const ln_10: float = 2.30258509299404568401799145468436421; } /* * Section: String Conversions */ /** * Converts a float to a string * * # Arguments * * * num - The float value */ #[inline(always)] pub pure fn to_str(num: float) -> ~str { let (r, _) = num::to_str_common( &num, 10u, true, true, num::SignNeg, num::DigAll); r } /** * Converts a float to a string in hexadecimal format * * # Arguments * * * num - The float value */ #[inline(always)] pub pure fn to_str_hex(num: float) -> ~str { let (r, _) = num::to_str_common( &num, 16u, true, true, num::SignNeg, num::DigAll); r } /** * Converts a float to a string in a given radix * * # Arguments * * * num - The float value * * radix - The base to use * * # Failure * * Fails if called on a special value like `inf`, `-inf` or `NaN` due to * possible misinterpretation of the result at higher bases. If those values * are expected, use `to_str_radix_special()` instead. */ #[inline(always)] pub pure fn to_str_radix(num: float, radix: uint) -> ~str { let (r, special) = num::to_str_common( &num, radix, true, true, num::SignNeg, num::DigAll); if special { die!(~"number has a special value, \ try to_str_radix_special() if those are expected") } r } /** * Converts a float to a string in a given radix, and a flag indicating * whether it's a special value * * # Arguments * * * num - The float value * * radix - The base to use */ #[inline(always)] pub pure fn to_str_radix_special(num: float, radix: uint) -> (~str, bool) { num::to_str_common(&num, radix, true, true, num::SignNeg, num::DigAll) } /** * Converts a float to a string with exactly the number of * provided significant digits * * # Arguments * * * num - The float value * * digits - The number of significant digits */ #[inline(always)] pub pure fn to_str_exact(num: float, digits: uint) -> ~str { let (r, _) = num::to_str_common( &num, 10u, true, true, num::SignNeg, num::DigExact(digits)); r } #[test] pub fn test_to_str_exact_do_decimal() { let s = to_str_exact(5.0, 4u); assert s == ~"5.0000"; } /** * Converts a float to a string with a maximum number of * significant digits * * # Arguments * * * num - The float value * * digits - The number of significant digits */ #[inline(always)] pub pure fn to_str_digits(num: float, digits: uint) -> ~str { let (r, _) = num::to_str_common( &num, 10u, true, true, num::SignNeg, num::DigMax(digits)); r } impl float: to_str::ToStr { #[inline(always)] pure fn to_str(&self) -> ~str { to_str_digits(*self, 8) } } impl float: num::ToStrRadix { #[inline(always)] pure fn to_str_radix(&self, radix: uint) -> ~str { to_str_radix(*self, radix) } } /** * Convert a string in base 10 to a float. * Accepts a optional decimal exponent. * * This function accepts strings such as * * * '3.14' * * '+3.14', equivalent to '3.14' * * '-3.14' * * '2.5E10', or equivalently, '2.5e10' * * '2.5E-10' * * '.' (understood as 0) * * '5.' * * '.5', or, equivalently, '0.5' * * '+inf', 'inf', '-inf', 'NaN' * * Leading and trailing whitespace represent an error. * * # Arguments * * * num - A string * * # Return value * * `none` if the string did not represent a valid number. Otherwise, * `Some(n)` where `n` is the floating-point number represented by `num`. */ #[inline(always)] pub pure fn from_str(num: &str) -> Option { num::from_str_common(num, 10u, true, true, true, num::ExpDec, false) } /** * Convert a string in base 16 to a float. * Accepts a optional binary exponent. * * This function accepts strings such as * * * 'a4.fe' * * '+a4.fe', equivalent to 'a4.fe' * * '-a4.fe' * * '2b.aP128', or equivalently, '2b.ap128' * * '2b.aP-128' * * '.' (understood as 0) * * 'c.' * * '.c', or, equivalently, '0.c' * * '+inf', 'inf', '-inf', 'NaN' * * Leading and trailing whitespace represent an error. * * # Arguments * * * num - A string * * # Return value * * `none` if the string did not represent a valid number. Otherwise, * `Some(n)` where `n` is the floating-point number represented by `[num]`. */ #[inline(always)] pub pure fn from_str_hex(num: &str) -> Option { num::from_str_common(num, 16u, true, true, true, num::ExpBin, false) } /** * Convert a string in an given base to a float. * * Due to possible conflicts, this function does **not** accept * the special values `inf`, `-inf`, `+inf` and `NaN`, **nor** * does it recognize exponents of any kind. * * Leading and trailing whitespace represent an error. * * # Arguments * * * num - A string * * radix - The base to use. Must lie in the range [2 .. 36] * * # Return value * * `none` if the string did not represent a valid number. Otherwise, * `Some(n)` where `n` is the floating-point number represented by `num`. */ #[inline(always)] pub pure fn from_str_radix(num: &str, radix: uint) -> Option { num::from_str_common(num, radix, true, true, false, num::ExpNone, false) } impl float: from_str::FromStr { #[inline(always)] static pure fn from_str(val: &str) -> Option { from_str(val) } } impl float: num::FromStrRadix { #[inline(always)] static pure fn from_str_radix(val: &str, radix: uint) -> Option { from_str_radix(val, radix) } } /** * Section: Arithmetics */ /** * Compute the exponentiation of an integer by another integer as a float * * # Arguments * * * x - The base * * pow - The exponent * * # Return value * * `NaN` if both `x` and `pow` are `0u`, otherwise `x^pow` */ pub pure fn pow_with_uint(base: uint, pow: uint) -> float { if base == 0u { if pow == 0u { return NaN as float; } return 0.; } let mut my_pow = pow; let mut total = 1f; let mut multiplier = base as float; while (my_pow > 0u) { if my_pow % 2u == 1u { total = total * multiplier; } my_pow /= 2u; multiplier *= multiplier; } return total; } #[inline(always)] pub pure fn is_positive(x: float) -> bool { f64::is_positive(x as f64) } #[inline(always)] pub pure fn is_negative(x: float) -> bool { f64::is_negative(x as f64) } #[inline(always)] pub pure fn is_nonpositive(x: float) -> bool { f64::is_nonpositive(x as f64) } #[inline(always)] pub pure fn is_nonnegative(x: float) -> bool { f64::is_nonnegative(x as f64) } #[inline(always)] pub pure fn is_zero(x: float) -> bool { f64::is_zero(x as f64) } #[inline(always)] pub pure fn is_infinite(x: float) -> bool { f64::is_infinite(x as f64) } #[inline(always)] pub pure fn is_finite(x: float) -> bool { f64::is_finite(x as f64) } #[inline(always)] pub pure fn is_NaN(x: float) -> bool { f64::is_NaN(x as f64) } #[inline(always)] pub pure fn abs(x: float) -> float { unsafe { f64::abs(x as f64) as float } } #[inline(always)] pub pure fn sqrt(x: float) -> float { unsafe { f64::sqrt(x as f64) as float } } #[inline(always)] pub pure fn atan(x: float) -> float { unsafe { f64::atan(x as f64) as float } } #[inline(always)] pub pure fn sin(x: float) -> float { unsafe { f64::sin(x as f64) as float } } #[inline(always)] pub pure fn cos(x: float) -> float { unsafe { f64::cos(x as f64) as float } } #[inline(always)] pub pure fn tan(x: float) -> float { unsafe { f64::tan(x as f64) as float } } #[cfg(notest)] impl float : Eq { pure fn eq(&self, other: &float) -> bool { (*self) == (*other) } pure fn ne(&self, other: &float) -> bool { (*self) != (*other) } } #[cfg(notest)] impl float : Ord { pure fn lt(&self, other: &float) -> bool { (*self) < (*other) } pure fn le(&self, other: &float) -> bool { (*self) <= (*other) } pure fn ge(&self, other: &float) -> bool { (*self) >= (*other) } pure fn gt(&self, other: &float) -> bool { (*self) > (*other) } } impl float: num::Num { #[inline(always)] pub pure fn add(&self, other: &float) -> float { return *self + *other; } #[inline(always)] pub pure fn sub(&self, other: &float) -> float { return *self - *other; } #[inline(always)] pub pure fn mul(&self, other: &float) -> float { return *self * *other; } #[inline(always)] pub pure fn div(&self, other: &float) -> float { return *self / *other; } #[inline(always)] pure fn modulo(&self, other: &float) -> float { return *self % *other; } #[inline(always)] pure fn neg(&self) -> float { return -*self; } } impl float: num::Zero { #[inline(always)] static pure fn zero() -> float { 0.0 } } impl float: num::One { #[inline(always)] static pure fn one() -> float { 1.0 } } pub impl float: NumCast { /** * Cast `n` to a `float` */ #[inline(always)] static pure fn from(n: N) -> float { n.to_float() } #[inline(always)] pure fn to_u8(&self) -> u8 { *self as u8 } #[inline(always)] pure fn to_u16(&self) -> u16 { *self as u16 } #[inline(always)] pure fn to_u32(&self) -> u32 { *self as u32 } #[inline(always)] pure fn to_u64(&self) -> u64 { *self as u64 } #[inline(always)] pure fn to_uint(&self) -> uint { *self as uint } #[inline(always)] pure fn to_i8(&self) -> i8 { *self as i8 } #[inline(always)] pure fn to_i16(&self) -> i16 { *self as i16 } #[inline(always)] pure fn to_i32(&self) -> i32 { *self as i32 } #[inline(always)] pure fn to_i64(&self) -> i64 { *self as i64 } #[inline(always)] pure fn to_int(&self) -> int { *self as int } #[inline(always)] pure fn to_f32(&self) -> f32 { *self as f32 } #[inline(always)] pure fn to_f64(&self) -> f64 { *self as f64 } #[inline(always)] pure fn to_float(&self) -> float { *self } } impl float: num::Round { #[inline(always)] pure fn round(&self, mode: num::RoundMode) -> float { match mode { num::RoundDown => f64::floor(*self as f64) as float, num::RoundUp => f64::ceil(*self as f64) as float, num::RoundToZero if is_negative(*self) => f64::ceil(*self as f64) as float, num::RoundToZero => f64::floor(*self as f64) as float, num::RoundFromZero if is_negative(*self) => f64::floor(*self as f64) as float, num::RoundFromZero => f64::ceil(*self as f64) as float } } #[inline(always)] pure fn floor(&self) -> float { f64::floor(*self as f64) as float} #[inline(always)] pure fn ceil(&self) -> float { f64::ceil(*self as f64) as float} #[inline(always)] pure fn fract(&self) -> float { if is_negative(*self) { (*self) - (f64::ceil(*self as f64) as float) } else { (*self) - (f64::floor(*self as f64) as float) } } } #[test] pub fn test_from_str() { assert from_str(~"3") == Some(3.); assert from_str(~"3.14") == Some(3.14); assert from_str(~"+3.14") == Some(3.14); assert from_str(~"-3.14") == Some(-3.14); assert from_str(~"2.5E10") == Some(25000000000.); assert from_str(~"2.5e10") == Some(25000000000.); assert from_str(~"25000000000.E-10") == Some(2.5); assert from_str(~".") == Some(0.); assert from_str(~".e1") == Some(0.); assert from_str(~".e-1") == Some(0.); assert from_str(~"5.") == Some(5.); assert from_str(~".5") == Some(0.5); assert from_str(~"0.5") == Some(0.5); assert from_str(~"-.5") == Some(-0.5); assert from_str(~"-5") == Some(-5.); assert from_str(~"inf") == Some(infinity); assert from_str(~"+inf") == Some(infinity); assert from_str(~"-inf") == Some(neg_infinity); // note: NaN != NaN, hence this slightly complex test match from_str(~"NaN") { Some(f) => assert is_NaN(f), None => die!() } // note: -0 == 0, hence these slightly more complex tests match from_str(~"-0") { Some(v) if is_zero(v) => assert is_negative(v), _ => die!() } match from_str(~"0") { Some(v) if is_zero(v) => assert is_positive(v), _ => die!() } assert from_str(~"").is_none(); assert from_str(~"x").is_none(); assert from_str(~" ").is_none(); assert from_str(~" ").is_none(); assert from_str(~"e").is_none(); assert from_str(~"E").is_none(); assert from_str(~"E1").is_none(); assert from_str(~"1e1e1").is_none(); assert from_str(~"1e1.1").is_none(); assert from_str(~"1e1-1").is_none(); } #[test] pub fn test_from_str_hex() { assert from_str_hex(~"a4") == Some(164.); assert from_str_hex(~"a4.fe") == Some(164.9921875); assert from_str_hex(~"-a4.fe") == Some(-164.9921875); assert from_str_hex(~"+a4.fe") == Some(164.9921875); assert from_str_hex(~"ff0P4") == Some(0xff00 as float); assert from_str_hex(~"ff0p4") == Some(0xff00 as float); assert from_str_hex(~"ff0p-4") == Some(0xff as float); assert from_str_hex(~".") == Some(0.); assert from_str_hex(~".p1") == Some(0.); assert from_str_hex(~".p-1") == Some(0.); assert from_str_hex(~"f.") == Some(15.); assert from_str_hex(~".f") == Some(0.9375); assert from_str_hex(~"0.f") == Some(0.9375); assert from_str_hex(~"-.f") == Some(-0.9375); assert from_str_hex(~"-f") == Some(-15.); assert from_str_hex(~"inf") == Some(infinity); assert from_str_hex(~"+inf") == Some(infinity); assert from_str_hex(~"-inf") == Some(neg_infinity); // note: NaN != NaN, hence this slightly complex test match from_str_hex(~"NaN") { Some(f) => assert is_NaN(f), None => die!() } // note: -0 == 0, hence these slightly more complex tests match from_str_hex(~"-0") { Some(v) if is_zero(v) => assert is_negative(v), _ => die!() } match from_str_hex(~"0") { Some(v) if is_zero(v) => assert is_positive(v), _ => die!() } assert from_str_hex(~"e") == Some(14.); assert from_str_hex(~"E") == Some(14.); assert from_str_hex(~"E1") == Some(225.); assert from_str_hex(~"1e1e1") == Some(123361.); assert from_str_hex(~"1e1.1") == Some(481.0625); assert from_str_hex(~"").is_none(); assert from_str_hex(~"x").is_none(); assert from_str_hex(~" ").is_none(); assert from_str_hex(~" ").is_none(); assert from_str_hex(~"p").is_none(); assert from_str_hex(~"P").is_none(); assert from_str_hex(~"P1").is_none(); assert from_str_hex(~"1p1p1").is_none(); assert from_str_hex(~"1p1.1").is_none(); assert from_str_hex(~"1p1-1").is_none(); } #[test] pub fn test_to_str_hex() { assert to_str_hex(164.) == ~"a4"; assert to_str_hex(164.9921875) == ~"a4.fe"; assert to_str_hex(-164.9921875) == ~"-a4.fe"; assert to_str_hex(0xff00 as float) == ~"ff00"; assert to_str_hex(-(0xff00 as float)) == ~"-ff00"; assert to_str_hex(0.) == ~"0"; assert to_str_hex(15.) == ~"f"; assert to_str_hex(-15.) == ~"-f"; assert to_str_hex(0.9375) == ~"0.f"; assert to_str_hex(-0.9375) == ~"-0.f"; assert to_str_hex(infinity) == ~"inf"; assert to_str_hex(neg_infinity) == ~"-inf"; assert to_str_hex(NaN) == ~"NaN"; assert to_str_hex(0.) == ~"0"; assert to_str_hex(-0.) == ~"-0"; } #[test] pub fn test_to_str_radix() { assert to_str_radix(36., 36u) == ~"10"; assert to_str_radix(8.125, 2u) == ~"1000.001"; } #[test] pub fn test_from_str_radix() { assert from_str_radix(~"10", 36u) == Some(36.); assert from_str_radix(~"1000.001", 2u) == Some(8.125); } #[test] pub fn test_positive() { assert(is_positive(infinity)); assert(is_positive(1.)); assert(is_positive(0.)); assert(!is_positive(-1.)); assert(!is_positive(neg_infinity)); assert(!is_positive(1./neg_infinity)); assert(!is_positive(NaN)); } #[test] pub fn test_negative() { assert(!is_negative(infinity)); assert(!is_negative(1.)); assert(!is_negative(0.)); assert(is_negative(-1.)); assert(is_negative(neg_infinity)); assert(is_negative(1./neg_infinity)); assert(!is_negative(NaN)); } #[test] pub fn test_nonpositive() { assert(!is_nonpositive(infinity)); assert(!is_nonpositive(1.)); assert(!is_nonpositive(0.)); assert(is_nonpositive(-1.)); assert(is_nonpositive(neg_infinity)); assert(is_nonpositive(1./neg_infinity)); assert(!is_nonpositive(NaN)); } #[test] pub fn test_nonnegative() { assert(is_nonnegative(infinity)); assert(is_nonnegative(1.)); assert(is_nonnegative(0.)); assert(!is_nonnegative(-1.)); assert(!is_nonnegative(neg_infinity)); assert(!is_nonnegative(1./neg_infinity)); assert(!is_nonnegative(NaN)); } #[test] pub fn test_to_str_inf() { assert to_str_digits(infinity, 10u) == ~"inf"; assert to_str_digits(-infinity, 10u) == ~"-inf"; } #[test] pub fn test_round() { assert round(5.8) == 6.0; assert round(5.2) == 5.0; assert round(3.0) == 3.0; assert round(2.5) == 3.0; assert round(-3.5) == -4.0; } #[test] pub fn test_num() { let ten: float = num::cast(10); let two: float = num::cast(2); assert (ten.add(&two) == num::cast(12)); assert (ten.sub(&two) == num::cast(8)); assert (ten.mul(&two) == num::cast(20)); assert (ten.div(&two) == num::cast(5)); assert (ten.modulo(&two) == num::cast(0)); } #[test] fn test_numcast() { assert (20u == 20f.to_uint()); assert (20u8 == 20f.to_u8()); assert (20u16 == 20f.to_u16()); assert (20u32 == 20f.to_u32()); assert (20u64 == 20f.to_u64()); assert (20i == 20f.to_int()); assert (20i8 == 20f.to_i8()); assert (20i16 == 20f.to_i16()); assert (20i32 == 20f.to_i32()); assert (20i64 == 20f.to_i64()); assert (20f == 20f.to_float()); assert (20f32 == 20f.to_f32()); assert (20f64 == 20f.to_f64()); assert (20f == NumCast::from(20u)); assert (20f == NumCast::from(20u8)); assert (20f == NumCast::from(20u16)); assert (20f == NumCast::from(20u32)); assert (20f == NumCast::from(20u64)); assert (20f == NumCast::from(20i)); assert (20f == NumCast::from(20i8)); assert (20f == NumCast::from(20i16)); assert (20f == NumCast::from(20i32)); assert (20f == NumCast::from(20i64)); assert (20f == NumCast::from(20f)); assert (20f == NumCast::from(20f32)); assert (20f == NumCast::from(20f64)); assert (20f == num::cast(20u)); assert (20f == num::cast(20u8)); assert (20f == num::cast(20u16)); assert (20f == num::cast(20u32)); assert (20f == num::cast(20u64)); assert (20f == num::cast(20i)); assert (20f == num::cast(20i8)); assert (20f == num::cast(20i16)); assert (20f == num::cast(20i32)); assert (20f == num::cast(20i64)); assert (20f == num::cast(20f)); assert (20f == num::cast(20f32)); assert (20f == num::cast(20f64)); } // // Local Variables: // mode: rust // fill-column: 78; // indent-tabs-mode: nil // c-basic-offset: 4 // buffer-file-coding-system: utf-8-unix // End: //