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August 29, 2015 14:11
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| func s(x:Int)->[Int]{ | |
| return x<2 ? | |
| []: | |
| // Single line closure has implicit return | |
| // Closure type is Int->[Int] | |
| {[$0]+s(x/$0)}( // Argment to closure | |
| // Filter full range 2 to x and take first factor (non lazy) | |
| // x%x is guaranteed to be 0 so safe to take first element | |
| filter(2...x){x % $0 == 0}[0] | |
| ) | |
| } | |
| // With explict typed closures and a longer name | |
| func shortPrimeFactors(x:Int)->[Int]{ | |
| return x<2 ? | |
| []: | |
| // Single line closure has implicit return | |
| // Closure type is Int->[Int] | |
| {(i:Int)->[Int] in [i] + shortPrimeFactors(x / i)}( | |
| // Argment to closure | |
| // Filter full range 2 to x and take first factor (non lazy) | |
| // x%x is guaranteed to be 0 so safe to take first element | |
| filter(2...x){(n:Int)->Bool in x % n == 0}[0] | |
| ) | |
| } | |
| // As above but looking like line noise/Perl | |
| func p(x:Int)->[Int]{return x<2 ?[]:{[$0]+p(x/$0)}(filter(2...x){x%$0 == 0}[0])} |
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Awesome - thanks for that :-) Not seen a closure type inferred by being returned by an outer function before.