Created
June 10, 2015 12:38
-
-
Save oisdk/5b368feb66514cc0cf62 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
extension SequenceType { | |
func prefixWhile(condition: Generator.Element -> Bool) -> [Generator.Element] { | |
var g = self.generate() | |
return Array( anyGenerator { | |
if let n = g.next() where condition(n) { | |
return n | |
} else { | |
return nil | |
} | |
} ) | |
} | |
func drop(n: Int) -> [Generator.Element]{ | |
var g = self.generate() | |
for _ in 0..<n { g.next() } | |
return Array(AnySequence{g}) | |
} | |
func jump(n: Int) -> [Generator.Element] { | |
var g = self.generate() | |
return Array( anyGenerator { | |
for _ in 0..<n {g.next()} | |
return g.next() | |
} ) | |
} | |
func hop(n: Int) -> [Generator.Element] { | |
var g = self.generate() | |
return Array( anyGenerator { | |
defer { for _ in 0..<n {g.next()} } | |
return g.next() | |
} ) | |
} | |
func frame (n: Int) -> AnyGenerator<ArraySlice<Generator.Element>> { | |
var (g, count) = (self.generate(), 0) | |
var window: ArraySlice<Generator.Element>? = ArraySlice(anyGenerator{++count > n ? nil : g.next()}) | |
return anyGenerator { | |
defer { window = g.next().map{ dropFirst(window!) + [$0] } } | |
return window | |
} | |
} | |
} | |
func zipWithPadding < | |
S0: SequenceType, S1: SequenceType, E0, E1 where | |
S0.Generator.Element == E0, S1.Generator.Element == E1 | |
> (s0: S0, s1: S1) -> AnyGenerator<(E0?, E1?)> { | |
var (g0, g1) : | |
(S0.Generator?, S1.Generator?) = | |
(s0.generate(), s1.generate()) | |
return anyGenerator { | |
let e0: E0? = g0?.next() | |
let e1: E1? = g1?.next() | |
if e0 == nil { g0 = nil } | |
if e1 == nil { g1 = nil } | |
return (e0 != nil || e1 != nil) ? (e0, e1) : nil | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment