Bob Nystrom
aa72900a9e
- Delete wren_io.c, wren_io.h, and io.wren source files - Remove multi-arity print overloads and IO.read/IO.time methods - Add System class with print, printAll, write, writeAll methods to core.wren - Update all documentation examples and README to use System.print instead of IO.print
43 lines
960 B
Plaintext
43 lines
960 B
Plaintext
// Infinite iterator demonstrating that Sequence.where is not eager
|
|
class FibIterator {
|
|
construct new() {
|
|
_current = 0
|
|
_next = 1
|
|
}
|
|
|
|
iterate {
|
|
var sum = _current + _next
|
|
_current = _next
|
|
_next = sum
|
|
}
|
|
|
|
value { _current }
|
|
}
|
|
|
|
class Fib is Sequence {
|
|
construct new() {}
|
|
|
|
iterate(iterator) {
|
|
if (iterator == null) return FibIterator.new()
|
|
iterator.iterate
|
|
return iterator
|
|
}
|
|
|
|
iteratorValue(iterator) { iterator.value }
|
|
}
|
|
|
|
var largeFibs = Fib.new().where {|fib| fib > 100 }
|
|
var iterator = null
|
|
|
|
System.print(largeFibs is Sequence) // expect: true
|
|
System.print(largeFibs) // expect: instance of WhereSequence
|
|
|
|
iterator = largeFibs.iterate(iterator)
|
|
System.print(largeFibs.iteratorValue(iterator)) // expect: 144
|
|
|
|
iterator = largeFibs.iterate(iterator)
|
|
System.print(largeFibs.iteratorValue(iterator)) // expect: 233
|
|
|
|
iterator = largeFibs.iterate(iterator)
|
|
System.print(largeFibs.iteratorValue(iterator)) // expect: 377
|