This is a new doubly-linked list using owned nodes. In the forward direction, the list is linked with owned pointers, and the backwards direction is linked with &'static Node pointers.
This intends to replace the previous extra::DList that was using managed nodes and also featured freestanding nodes. The new List does not give access to the nodes, but means to implement all relevant linked-list methods.
The list supports pop_back, push_back, pop_front, push_front, front, back, iter, mut_iter, +more iterators, append, insert_ordered, and merge.
* Add a trait Deque for double ended sequences.
* Both List and Deque implement this trait. Rename Deque to ArrayDeque.
*The text has been updated to summarize resolved items*
## RFC Topics
### Resolved
* Should be in extra
* Representation for the backlinks
### Container Method Names and Trait Names and Type Names
* Location and name of trait `extra::collection::Deque`?
* Name of the ring buffer `extra::deque::ArrayDeque` ?
* Name of the doubly linked list `extra::dlist::List` ?
For container methods I think we have two options:
* Align with the existing methods on the vector. That would be `.push()`, `.pop()`, `.shift()`, `.unshift()`.
* Use the API described in https://github.com/mozilla/rust/wiki/Containers Obviously that's the way List is written right now.
Should we use `pop_front() -> Option<T>` or `pop_front() -> T` ?
### Benchmarks
Some basic bench numbers for List vs. Vec, Deque and *old DList*
This List implementation's performance is dominated by the allocation of Nodes required when pushing.
Iterate (by-ref) collection of 128 elements
test test_bench::bench_iter ... bench: 198 ns/iter (+/- 0)
test test_bench::bench_iter_mut ... bench: 294 ns/iter (+/- 0)
test test_bench::bench_iter_rev ... bench: 198 ns/iter (+/- 0)
test test_bench::bench_iter_mut_rev ... bench: 198 ns/iter (+/- 3)
test test_bench::bench_iter_vec ... bench: 101 ns/iter (+/- 0)
test test_bench::bench_iter_deque ... bench: 581 ns/iter (+/- 0)
test test_bench::bench_iter_dlist ... bench: 9262 ns/iter (+/- 273)
Sequence of `.push(elt)`, `.pop()` or equivalent at the tail end
test test_bench::bench_push_back_pop_back ... bench: 72 ns/iter (+/- 0)
test test_bench::bench_push_back_pop_back_vec ... bench: 5 ns/iter (+/- 0)
test test_bench::bench_push_back_pop_back_deque ... bench: 15 ns/iter (+/- 0)
test test_bench::bench_push_back_pop_back_dlist ... bench: 234 ns/iter (+/- 0)
Moves multibyte code to it's own function to make char_range_at
easier to inline, and faster for single and multibyte chars.
Benchmarked reading example.json 100 times, 1.18s before, 1.08s
after.
Currently, immediate values are copied into an alloca only to have an
addressable storage so that it can be used with memcpy. Obviously we
can skip the memcpy in this case.
An iterator that allows mutating the list is very useful but needs care
to not be unsound. ListIteration exposes only insert_before (used for
insert_ordered) and peek_next so far.
This is an owned sendable linked list which allows insertion and
deletion at both ends, with fast traversal through iteration, and fast
append/prepend.
It is indended to replace the previous managed DList with exposed list
nodes. It does not match it feature by feature, but DList could grow
more methods if needed.
This is much faster for strings, and eventually when there is a
buffered reader of some sort, will be much faster for files.
Reading example.json 100 times before was around 1.18s.
After:
- reading from string 0.68s
- reading from file 1.08s (extra time is all in io::Reader)
Also:
- fixes#7611 - error when parsing strings and we hit EOF
- updates definition of whitespace in json should only be the 4 ascii whitespace chars
All of the examples were still using `core::` instead of `std::` and needed a `use std::rand;` at the top to compile
Most of the examples had
`rng = rand::rng();`
instead of
`let mut rng = rand::rng();`
This implements the trait for vector iterators, replacing the reverse
iterator types. The methods will stay, for implementing the future
reverse Iterable traits and convenience.
This can also be trivially implemented for circular buffers and other
variants of arrays like strings and `SmallIntMap`/`SmallIntSet`.
The `DoubleEndedIterator` trait will allow for implementing algorithms
like in-place reverse on generic mutable iterators.
The naming (`Range` vs. `Iterator`, `Bidirectional` vs. `DoubleEnded`)
can be bikeshedded in the future.
This is much faster for strings, and eventually when there is a
buffered reader of some sort.
Reading example.json 100 times before was around 1.18s.
After:
- reading from string 0.68s
- reading from file 1.08s (extra time is all in io::Reader)
Added Add and Sub traits for pointer arithmetic. Any type that is a ```std::num::Int``` can be added to or subtracted from a pointer. Also my additions did not require any unsafe code, and the operators themselves are safe. Fixes#2122.
The examples were still using `core::` instead of `std::`
All of the examples needed a `use std::rand;` at the top to compile
Most of the examples had
`rng = rand::rng();`
instead of
`let mut rng = rand::rng();`
When building Rust libraries (e.g. librustc, libstd, etc), checks for
and verbosely removes previous build products before invoking rustc.
(Also, when Make variable VERBOSE is defined, it will list all of the
libraries matching the object library's glob after the rustc
invocation has completed.)
When installing Rust libraries, checks for previous libraries in
target install directory, but does not remove them.
The thinking behind these two different modes of operation is that the
installation target, unlike the build tree, is not under the control
of this infrastructure and it is not up to this Makefile to decide if
the previous libraries should be removed.
Fixes#3225 (at least in terms of mitigating the multiple library
problem by proactively warning the user about it.)
