This commit changes the ToStr trait to:
impl<T: fmt::Show> ToStr for T {
fn to_str(&self) -> ~str { format!("{}", *self) }
}
The ToStr trait has been on the chopping block for quite awhile now, and this is
the final nail in its coffin. The trait and the corresponding method are not
being removed as part of this commit, but rather any implementations of the
`ToStr` trait are being forbidden because of the generic impl. The new way to
get the `to_str()` method to work is to implement `fmt::Show`.
Formatting into a `&mut Writer` (as `format!` does) is much more efficient than
`ToStr` when building up large strings. The `ToStr` trait forces many
intermediate allocations to be made while the `fmt::Show` trait allows
incremental buildup in the same heap allocated buffer. Additionally, the
`fmt::Show` trait is much more extensible in terms of interoperation with other
`Writer` instances and in more situations. By design the `ToStr` trait requires
at least one allocation whereas the `fmt::Show` trait does not require any
allocations.
Closes#8242Closes#9806
This is PR is the beginning of a complete rewrite and ultimate removal of the `std::num::strconv` module (see #6220), and the removal of the `ToStrRadix` trait in favour of using the `std::fmt` functionality directly. This should make for a cleaner API, encourage less allocation, and make the implementation more comprehensible .
The `Formatter::{pad_integral, with_padding}` methods have also been refactored make things easier to understand.
The formatting tests for integers have been moved out of `run-pass/ifmt.rs` in order to provide more immediate feedback when building using `make check-stage2-std NO_REBUILD=1`.
Arbitrary radixes are now easier to use in format strings. For example:
~~~rust
assert_eq!(format!("{:04}", radix(3, 2)), ~"0011");
~~~
The benchmarks have been standardised between `std::num::strconv` and `std::num::fmt` to make it easier to compare the performance of the different implementations.
~~~
type | radix | std::num::strconv | std::num::fmt
======|=======|========================|======================
int | bin | 1748 ns/iter (+/- 150) | 321 ns/iter (+/- 25)
int | oct | 706 ns/iter (+/- 53) | 179 ns/iter (+/- 22)
int | dec | 640 ns/iter (+/- 59) | 207 ns/iter (+/- 10)
int | hex | 637 ns/iter (+/- 77) | 205 ns/iter (+/- 19)
int | 36 | 446 ns/iter (+/- 30) | 309 ns/iter (+/- 20)
------|-------|------------------------|----------------------
uint | bin | 1724 ns/iter (+/- 159) | 322 ns/iter (+/- 13)
uint | oct | 663 ns/iter (+/- 25) | 175 ns/iter (+/- 7)
uint | dec | 613 ns/iter (+/- 30) | 186 ns/iter (+/- 6)
uint | hex | 519 ns/iter (+/- 44) | 207 ns/iter (+/- 20)
uint | 36 | 418 ns/iter (+/- 16) | 308 ns/iter (+/- 32)
~~~
This is in preparation to remove the implementations of ToStrRadix in integers, and to remove the associated logic from `std::num::strconv`.
The parts that still need to be liberated are:
- `std::fmt::Formatter::runplural`
- `num::{bigint, complex, rational}`
This removes the `Primitive::{bits, bytes, is_signed}` methods and removes the operator trait constraints, for the reasons outlined below:
- The `Primitive::{bits, bytes}` associated functions were originally added to reflect the existing `BITS` and `BYTES` statics included in the numeric modules. These statics are only exist as a workaround for Rust's lack of CTFE, and should probably be deprecated in the future in favor of using the `std::mem::size_of` function (see #11621).
- `Primitive::is_signed` seems to be of little utility and does not seem to be used anywhere in the Rust compiler or libraries. It is also rather ugly to call due to the `Option<Self>` workaround for #8888.
- The operator trait constraints are already covered by the `Num` trait.
This large commit implements and `html` output option for rustdoc_ng. The
executable has been altered to be invoked as "rustdoc_ng html <crate>" and
it will dump everything into the local "doc" directory. JSON can still be
generated by changing 'html' to 'json'.
This also fixes a number of bugs in rustdoc_ng relating to comment stripping,
along with some other various issues that I found along the way.
The `make doc` command has been altered to generate the new documentation into
the `doc/ng/$(CRATE)` directories.
Remove these in favor of the two traits themselves and the wrapper
function std::from_str::from_str.
Add the function std::num::from_str_radix in the corresponding role for
the FromStrRadix trait.
This removes the stacking of type parameters that occurs when invoking
trait methods, and fixes all places in the standard library that were
relying on it. It is somewhat awkward in places; I think we'll probably
want something like the `Foo::<for T>::new()` syntax.
Basically, generic containers should not use the default methods since a
type of elements may not guarantees total order. str could use them
since u8's Ord guarantees total order. Floating point numbers are also
broken with the default methods because of NaN. Thanks for @thestinger.
Timespec also guarantees total order AIUI. I'm unsure whether
extra::semver::Identifier does so I left it alone. Proof needed.
Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
The free-standing functions in f32, f64, i8, i16, i32, i64, u8, u16,
u32, u64, float, int, and uint are replaced with generic functions in
num instead.
If you were previously using any of those functions, just replace them
with the corresponding function with the same name in num.
Note: If you were using a function that corresponds to an operator, use
the operator instead.
