This is a temporary trait until we have default methods. We don't want to encumber all implementors of Ord by requiring them to implement these functions, but at the same time we want to be able to take advantage of the speed of the specific numeric functions (like the `fmin` and `fmax` intrinsics).
Having three traits for primitive ints/uints seemed rather excessive. If users wish to specify between them they can simply combine Int with either the Signed and Unsigned traits. For example: fn foo<T: Int + Signed>() { … }
As part of the numeric trait reform (see issue #4819), I have added the following traits to `core::num` and implemented them for floating point types:
~~~rust
pub trait Round {
fn floor(&self) -> Self;
fn ceil(&self) -> Self;
fn round(&self) -> Self;
fn trunc(&self) -> Self;
fn fract(&self) -> Self;
}
pub trait Fractional: Num
+ Ord
+ Round
+ Quot<Self,Self> {
fn recip(&self) -> Self;
}
pub trait Real: Signed
+ Fractional {
// Common Constants
fn pi() -> Self;
fn two_pi() -> Self;
fn frac_pi_2() -> Self;
fn frac_pi_3() -> Self;
fn frac_pi_4() -> Self;
fn frac_pi_6() -> Self;
fn frac_pi_8() -> Self;
fn frac_1_pi() -> Self;
fn frac_2_pi() -> Self;
fn frac_2_sqrtpi() -> Self;
fn sqrt2() -> Self;
fn frac_1_sqrt2() -> Self;
fn e() -> Self;
fn log2_e() -> Self;
fn log10_e() -> Self;
fn log_2() -> Self;
fn log_10() -> Self;
// Exponential functions
fn pow(&self, n: Self) -> Self;
fn exp(&self) -> Self;
fn exp2(&self) -> Self;
fn expm1(&self) -> Self;
fn ldexp(&self, n: int) -> Self;
fn log(&self) -> Self;
fn log2(&self) -> Self;
fn log10(&self) -> Self;
fn log_radix(&self) -> Self;
fn ilog_radix(&self) -> int;
fn sqrt(&self) -> Self;
fn rsqrt(&self) -> Self;
fn cbrt(&self) -> Self;
// Angular conversions
fn to_degrees(&self) -> Self;
fn to_radians(&self) -> Self;
// Triganomic functions
fn hypot(&self, other: Self) -> Self;
fn sin(&self) -> Self;
fn cos(&self) -> Self;
fn tan(&self) -> Self;
// Inverse triganomic functions
fn asin(&self) -> Self;
fn acos(&self) -> Self;
fn atan(&self) -> Self;
fn atan2(&self, other: Self) -> Self;
// Hyperbolic triganomic functions
fn sinh(&self) -> Self;
fn cosh(&self) -> Self;
fn tanh(&self) -> Self;
}
/// Methods that are harder to implement and not commonly used.
pub trait RealExt: Real {
// Gamma functions
fn lgamma(&self) -> (int, Self);
fn tgamma(&self) -> Self;
// Bessel functions
fn j0(&self) -> Self;
fn j1(&self) -> Self;
fn jn(&self, n: int) -> Self;
fn y0(&self) -> Self;
fn y1(&self) -> Self;
fn yn(&self, n: int) -> Self;
}
~~~
The constants in `Real` could be [associated items](http://smallcultfollowing.com/babysteps/blog/2013/04/03/associated-items-continued/) in the future (see issue #5527). At the moment I have left the constants in `{float|f32|f64}::consts` in case folks need to access these at compile time. There are also instances of `int` in `Real` and `RealExt`. In the future these could be replaced with an associated `INTEGER` type on `Real`.
`Natural` has also been renamed to `Integer`. This is because `Natural` normally means 'positive integer' in mathematics. It is therefore strange to implement it on signed integer types. `Integer` is probably a better choice.
I have also switched some of the `Integer` methods to take borrowed pointers as arguments. This brings them in line with the `Quot` and `Rem` traits, and is be better for large Integer types like `BigInt` and `BigUint` because they don't need to be copied unnecessarily.
There has also been considerable discussion on the mailing list and IRC about the renaming of the `Div` and `Modulo` traits to `Quot` and `Rem`. Depending on the outcome of these discussions they might be renamed again.
This brings them in line with the quot and rem traits, and is be better for large Integer types like BigInt and BigUint because they don't need to be copied unnecessarily.
'Natural' normally means 'positive integer' in mathematics. It is therefore strange to implement it on signed integer types. 'Integer' is probably a better choice.
From a cursory `git grep` this removes the last part of `core` that requires on `@` (other than `io` and the task local data section).
It renames `RandRes` to ~~StdRng~~ `IsaacRng` and `XorShiftState` to `XorShiftRng` as well as moving their constructors to static methods. To go with this, it adds `rng()` which is designed to be used when the programmer just wants a random number generator, without caring about which exact algorithm is being used.
It also removes all the `gen_int`, `gen_uint`, `gen_char` (etc) methods on `RngUtil` (by moving the defintions to the actual `Rand` instances). The replacement is using `RngUtil::gen`, either type-inferred or with an annotation (`rng.gen::<uint>()`).
I tried to have the `Rng` and `RngUtil` traits exported by `core::prelude` (since `core::rand` (except for `random()`) is useless without them), but this caused [an explosion of (seemingly unrelated) `error: unresolved import`'s](https://gist.github.com/5451839).
This moves all the basic random value generation into the Rand instances for
each type and then removes the `gen_int`, `gen_char` (etc) methods on RngUtil,
leaving only the generic `gen` and the more specialised methods.
Also, removes some imports that are redundant due to a `use core::prelude::*`
statement.
As part of the numeric trait reform (see issue #4819), I have added the following traits to `core::num` and implemented them for the appropriate types:
~~~rust
pub trait Signed: Num
+ Neg<Self> {
fn abs(&self) -> Self;
fn signum(&self) -> Self;
fn is_positive(&self) -> bool;
fn is_negative(&self) -> bool;
}
pub trait Unsigned: Num {}
pub trait Natural: Num
+ Ord
+ Quot<Self,Self>
+ Rem<Self,Self> {
fn div(&self, other: Self) -> Self;
fn modulo(&self, other: Self) -> Self;
fn div_mod(&self, other: Self) -> (Self,Self);
fn quot_rem(&self, other: Self) -> (Self,Self);
fn gcd(&self, other: Self) -> Self;
fn lcm(&self, other: Self) -> Self;
fn divisible_by(&self, other: Self) -> bool;
fn is_even(&self) -> bool;
fn is_odd(&self) -> bool;
}
~~~
I have not implemented `Natural` for `BigInt` and `BigUInt` because they're a little over my head. Help with this would be most appreciated.
This adds the following methods to ints and uints:
- div
- modulo
- div_mod
- quot_rem
- gcd
- lcm
- divisible_by
- is_even
- is_odd
I have not implemented Natural for BigInt and BigUInt because they're a little over my head.
Because unsafe functions are never warned about, then all `unsafe` blocks in unsafe functions should definitely be warned about (no need to be redundant). This fixes this case, adds tests, cleans up remaining cases, and then fixes a few other import warnings being spit out.
This fixes#5976.
It also removes `os::waitpid` in favour of (the existing) `run::waitpid`. I included this change because I figured it is kind of related.
r?
- The return value meant different things on different
platforms (on windows, it was the exit code, on unix it was
the status information returned from waitpid).
- It was undocumented.
- There also exists run::waitpid, which does much the same
thing but has a more consistent return value and also some
documentation.
