- Start Date: 2015-01-13
- RFC PR: rust-lang/rfcs#580
- Rust Issue: rust-lang/rust#22479
Summary
Rename (maybe one of) the standard collections, so as to make the names more consistent. Currently, among all the alternatives, renaming BinaryHeap
to BinHeap
is the slightly preferred solution.
Motivation
In this comment in the Rust 1.0.0-alpha announcement thread in /r/programming, it was pointed out that Rust’s std collections had inconsistent names. Particularly, the abbreviation rules of the names seemed unclear.
The current collection names (and their longer versions) are:
Vec
->Vector
BTreeMap
BTreeSet
BinaryHeap
Bitv
->BitVec
->BitVector
BitvSet
->BitVecSet
->BitVectorSet
DList
->DoublyLinkedList
HashMap
HashSet
RingBuf
->RingBuffer
VecMap
->VectorMap
The abbreviation rules do seem unclear. Sometimes the first word is abbreviated, sometimes the last. However there are also cases where the names are not abbreviated. Bitv
, BitvSet
and DList
seem strange on first glance. Such inconsistencies are undesirable, as Rust should not give an impression as “the promising language that has strangely inconsistent naming conventions for its standard collections”.
Also, it should be noted that traditionally ring buffers have fixed sizes, but Rust’s RingBuf
does not. So it is preferable to rename it to something clearer, in order to avoid incorrect assumptions and surprises.
Detailed design
First some general naming rules should be established.
- At least maintain module level consistency when abbreviations are concerned.
- Prefer commonly used abbreviations.
- When in doubt, prefer full names to abbreviated ones.
- Don’t be dogmatic.
And the new names:
Vec
BTreeMap
BTreeSet
BinaryHeap
Bitv
->BitVec
BitvSet
->BitSet
DList
->LinkedList
HashMap
HashSet
RingBuf
->VecDeque
VecMap
The following changes should be made:
- Rename
Bitv
,BitvSet
,DList
andRingBuf
. Change affected codes accordingly. - If necessary, redefine the original names as aliases of the new names, and mark them as deprecated. After a transition period, remove the original names completely.
Why prefer full names when in doubt?
The naming rules should apply not only to standard collections, but also to other codes. It is (comparatively) easier to maintain a higher level of naming consistency by preferring full names to abbreviated ones when in doubt. Because given a full name, there are possibly many abbreviated forms to choose from. Which one should be chosen and why? It is hard to write down guidelines for that.
For example, the name BinaryBuffer
has at least three convincing abbreviated forms: BinBuffer
/BinaryBuf
/BinBuf
. Which one would be the most preferred? Hard to say. But it is clear that the full name BinaryBuffer
is not a bad name.
However, if there is a convincing reason, one should not hesitate using abbreviated names. A series of names like BinBuffer/OctBuffer/HexBuffer
is very natural. Also, few would think that AtomicallyReferenceCounted
, the full name of Arc
, is a good type name.
Advantages of the new names:
Vec
: The name of the most frequently used Rust collection is left unchanged (and by extensionVecMap
), so the scope of the changes are greatly reduced.Vec
is an exception to the “prefer full names” rule because it is the collection in Rust.BitVec
:Bitv
is a very unusual abbreviation ofBitVector
, butBitVec
is a good one givenVector
is shortened toVec
.BitSet
: Technically,BitSet
is a synonym ofBitVec(tor)
, but it hasSet
in its name and can be interpreted as a set-like “view” into the underlying bit array/vector, soBitSet
is a good name. No need to have an additionalv
.LinkedList
:DList
doesn’t say much about what it actually is.LinkedList
is not too long (likeDoublyLinkedList
) and it being a doubly-linked list follows Java/C#’s traditions.VecDeque
: This name exposes some implementation details and signifies its “interface” just likeHashSet
, and it doesn’t have the “fixed-size” connotation thatRingBuf
has. Also,Deque
is commonly preferred toDoubleEndedQueue
, it is clear that the former should be chosen.
Drawbacks
- There will be breaking changes to standard collections that are already marked
stable
.
Alternatives
A. Keep the status quo:
And Rust’s standard collections will have some strange names and no consistent naming rules.
B. Also rename Vec
to Vector
:
And by extension, Bitv
to BitVector
and VecMap
to VectorMap
.
This means breaking changes at a larger scale. Given that Vec
is the collection of Rust, we can have an exception here.
C. Rename DList
to DLinkedList
, not LinkedList
:
It is clearer, but also inconsistent with the other names by having a single-lettered abbreviation of Doubly
. As Java/C# also have doubly-linked LinkedList
, it is not necessary to use the additional D
.
D. Also rename BinaryHeap
to BinHeap
.
BinHeap
can also mean BinomialHeap
, so BinaryHeap
is the better name here.
E. Rename RingBuf
to RingBuffer
, or do not rename RingBuf
at all.
Doing so would fail to stop people from making the incorrect assumption that Rust’s RingBuf
s have fixed sizes.
Unresolved questions
None.