[swift-evolution] Proposal: Add SequenceType.first
Susan Cheng
susan.doggie at gmail.com
Sat Jan 2 06:24:44 CST 2016
Consider this,
struct RandomGenerator : GeneratorType, SequenceType {
mutating func next() -> UInt32? {
return arc4random()
}
}
what's the expected result of follows??
let random = RandomGenerator()
let resultA = random.first
let resultB = random.first
let resultC = Array(random.prefix(4))
let resultD = Array(random.prefix(4))
all should agree that resultC and resultD will get different array. what's
about with resultA and resultB?
Gwendal Roué <gwendal.roue at gmail.com> 於 2016年1月2日 下午8:13 寫道:
Hello,
My two cents: I feel uncomfortable with SequenceType.first since
SequenceType clearly states that it may be destructed on iteration.
Compare :
seq.generate().next() // clear that it may give another result if called
twice
seq.first // unclear that it may give another result if called
twice
Gwendal
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20160102/f38decf3/attachment.html>
More information about the swift-evolution
mailing list