[swift-evolution] ed/ing, InPlace, Set/SetAlgebra naming resolution

[Dave Abrahams]

on Sat Feb 13 2016, Dave Abrahams <dabrahams-AT-apple.com> wrote:

> The following message is a courtesy copy of an article
> that has been posted to gmane.comp.lang.swift.evolution as well.
>
> on Fri Feb 12 2016, Ricardo Parada <swift-evolution at swift.org> wrote:
>
>> Hi all,
>>
>> I can’t make up my mind.  Let me propose two different alternatives
>> that I’m not sure if they have been considered:
>>
>> ALTERNATIVE 1
>>
>> Non-mutable (noun-based)
>>
>> -  func union(other: Self) -> Self
>> +  func union(other: Self) -> Self		Assumes union is a noun, i.e. not a verb
>>
>> -  func intersect(other: Self) -> Self
>> +  func intersection(other: Self) -> Self
>>
>> -  func subtract(other: Self) -> Self
>> +  func subtraction(other: Self) -> Self
>>
>> -  func exclusiveOr(other: Self) -> Self
>> +  func symmetricSubtraction(other: Self) -> Self
>>
>> Mutable (verb-based)
>>
>> -  mutating func unionInPlace(other: Self)
>> +  mutating func unite(other: Self)
>>
>> -  mutating func intersectInPlace(other: Self)
>> +  mutating func intersect(other: Self)
>>
>> -  mutating func subtractInPlace(other: Self)
>> +  mutating func subtract(other: Self)
>>
>> -  mutating func exclusiveOrInPlace(other: Self)
>> +  mutating func symmetricSubtract(other: Self)
>>
>> Comments: 
>>
>> With this alternative we keep the union name which I assume is
>> popular.  However, one has to accept unite as a verb (for the mutable
>> version) as I wanted all the mutable methods use verbs for
>> consistency.  I think unite is acceptable because it can be found in
>> the dictionary and it is a verb.
>>
>> Notice that all the non-mutable methods use nouns: union,
>> intersection, subtraction and symmetricSubtraction.
>>
>> I understand some may oppose to symmetricSubtraction saying that
>> symmetricSubraction is not as common as "exclusive or".  However,
>> using symmetricSubtraction is consistent with subtraction and it hints
>> to a variation of the “subtraction" operation.  We will get used to it
>> quickly / easily.
>>
>> The mutable methods all use verbs:  unite, intersect, subtract and symmetricSubtract.
>>
>> ALTERNATIVE 2
>>
>> Non-mutable
>>
>> -  func union(other: Self) -> Self
>> +  func adding(other: Self) -> Self
>>
>> -  func intersect(other: Self) -> Self
>> +  func intersecting(other: Self) -> Self
>>
>> -  func exclusiveOr(other: Self) -> Self
>> +  func exclusiveOring(other: Self) -> Self
>>
>> -  func subtract(other: Self) -> Self
>> +  func removing(other: Self) -> Self
>>
>> Mutable
>>
>> -  mutating func unionInPlace(other: Self)
>> +  mutating func add(other: Self)
>>
>> -  mutating func intersectInPlace(other: Self)
>> +  mutating func intersect(other: Self)
>>
>> -  mutating func exclusiveOrInPlace(other: Self)
>> +  mutating func exclusiveOr(other: Self)
>>
>> -  mutating func subtractInPlace(other: Self)
>> +  mutating func remove(other: Self)
>>
>> Comments: This alternative gives up on union in favor or add.  Many
>> may not like this, that is why I have it as the second alternative.
>> It brings back exclusiveOr and treats it as a verb.  Some may argue
>> that exclusiveOr is a noun for the "exclusive or" operation.
>
> If we are going to force Set fit the naming guidelines, I would prefer
> to stay away from the mathematical terms altogether.

Sorry, a few more notes about this:


>    func insertingContentsOf(other: Self) -> Self                 // union
>    mutating func insertContentsOf(other)

"merge" might be a better verb than "insert"

>    func members(in other: Self) -> Self                           // intersection
>    mutating func removeMembers(notIn: other)
>
>    func removingMembersAndAddingNonMembers(in other: Self) -> Self // symmetric difference
>    mutating func removeMembersAndAddingNonMembers(in other: Self)

Oops, left a stray "ing" in there:

    mutating func removeMembersAndAddNonMembers(in other: Self)

Another avenue for this one is:

    mutating func invertingMembershipOfContentsOf(other: Self)
    mutating func invertMembershipOfContentsOf(other: Self)

>    func removingMembers(in other: Self) -> Self                    // subtract
>    mutating func removeMembers(in other: Self)
>
> If it would help with clarity, we could replace "in" with "foundIn"
> above.

-- 
-Dave