1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
discard """
output: '''
0
1
2
3
4
1
start
false
0
1
2
end
@[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 18, 20, 21, 24, 27, 30, 36, 40, 42]
1002
0
1
2
7
'''
"""
import algorithm, math, sequtils, strutils
block t338:
proc moo(): iterator (): int =
iterator fooGen: int {.closure.} =
while true:
yield result
result.inc
return fooGen
var foo = moo()
for i in 0 .. 4:
echo foo()
block t8041:
iterator xy[T](a: T, b: set[T]): T =
if a in b:
yield a
for a in xy(1'i8, {}):
for b in xy(a, {}):
echo a
block t3837_chained:
iterator t1(): int {.closure.} =
yield 1
iterator t2(): int {.closure.} =
for i in t1():
yield i
for i in t2():
echo $i
proc iter1(): (iterator: int) =
let coll = [0,1,2]
result = iterator: int {.closure.} =
for i in coll:
yield i
proc iter2(it: (iterator: int)): (iterator: int) =
result = iterator: int {.closure.} =
echo finished(it)
for i in it():
yield i
echo "start"
let myiter1 = iter1()
let myiter2 = iter2(myiter1)
for i in myiter2():
echo i
echo "end"
type Iterable[T] = (iterator: T) | Slice[T]
## Everything that can be iterated over, iterators and slices so far.
proc toIter[T](s: Slice[T]): iterator: T =
## Iterate over a slice.
iterator it: T {.closure.} =
for x in s.a..s.b:
yield x
return it
proc toIter[T](i: iterator: T): iterator: T =
## Nop
i
iterator map[T,S](i: Iterable[T], f: proc(x: T): S): S =
let i = toIter(i)
for x in i():
yield f(x)
proc filter[T](i: Iterable[T], f: proc(x: T): bool): iterator: T =
let i = toIter(i)
iterator it: T {.closure.} =
for x in i():
if f(x):
yield x
result = it
iterator filter[T](i: Iterable[T], f: proc(x: T): bool): T =
let i = toIter(i)
for x in i():
if f(x):
yield x
var it = toSeq(filter(2..10, proc(x: int): bool = x mod 2 == 0))
doAssert it == @[2, 4, 6, 8, 10]
it = toSeq(map(filter(2..10, proc(x: int): bool = x mod 2 == 0), proc(x: int): int = x * 2))
doAssert it == @[4, 8, 12, 16, 20]
block t3221_complex:
iterator permutations[T](ys: openarray[T]): seq[T] =
var
d = 1
c = newSeq[int](ys.len)
xs = newSeq[T](ys.len)
for i, y in ys: xs[i] = y
yield xs
block outer:
while true:
while d > 1:
dec d
c[d] = 0
while c[d] >= d:
inc d
if d >= ys.len: break outer
let i = if (d and 1) == 1: c[d] else: 0
swap xs[i], xs[d]
yield xs
inc c[d]
proc dig_vectors(): void =
var v_nums: seq[int]
v_nums = newSeq[int](1)
for perm in permutations(toSeq(0 .. 1)):
v_nums[0] = 1
dig_vectors()
block t3499_keepstate:
proc slice[T](iter: iterator(): T {.closure.}, sl: auto): seq[T] =
var res: seq[int64] = @[]
var i = 0
for n in iter():
if i > sl.b:
break
if i >= sl.a:
res.add(n)
inc i
res
iterator harshad(): int64 {.closure.} =
for n in 1 ..< int64.high:
var sum = 0
for ch in string($n):
sum += parseInt("" & ch)
if n mod sum == 0:
yield n
echo harshad.slice 0 ..< 20
for n in harshad():
if n > 1000:
echo n
break
# bug #3499 last snippet fixed
# bug 705 last snippet fixed
block t1725_nested:
iterator factory(): int {.closure.} =
iterator bar(): int {.closure.} =
yield 0
yield 1
yield 2
for x in bar(): yield x
for x in factory():
echo x
block t2023_objiter:
type
Obj = object
iter: iterator (): int8 {.closure.}
iterator test(): int8 {.closure.} =
yield 7
proc init():Obj=
result.iter = test
var o = init()
echo(o.iter())
|
