1 files changed, 176 insertions, 0 deletions
diff --git a/tests/iter/tclosureiters.nim b/tests/iter/tclosureiters.nim
new file mode 100644
index 000000000..4a2639852
--- /dev/null
+++ b/tests/iter/tclosureiters.nim
@@ -0,0 +1,176 @@
+discard """
+  targets: "c js"
+  output: '''0
+1
+2
+3
+4
+5
+6
+7
+8
+9
+10
+5 5
+7 7
+9 9
+0
+0
+0
+0
+1
+2
+70
+0
+(1, 1)
+(1, 2)
+(1, 3)
+(2, 1)
+(2, 2)
+(2, 3)
+(3, 1)
+(3, 2)
+(3, 3)
+'''
+"""
+
+when true:
+  proc main() =
+    let
+      lo=0
+      hi=10
+
+    iterator itA(): int =
+      for x in lo..hi:
+        yield x
+
+    for x in itA():
+      echo x
+
+    var y: int
+
+    iterator itB(): int =
+      while y <= hi:
+        yield y
+        inc y
+
+    y = 5
+    for x in itB():
+      echo x, " ", y
+      inc y
+
+  main()
+
+
+iterator infinite(): int {.closure.} =
+  var i = 0
+  while true:
+    yield i
+    inc i
+
+iterator take[T](it: iterator (): T, numToTake: int): T {.closure.} =
+  var i = 0
+  for x in it():
+    if i >= numToTake:
+      break
+    yield x
+    inc i
+
+# gives wrong reasult (3 times 0)
+for x in infinite.take(3):
+  echo x
+
+# does what we want
+let inf = infinite
+for x in inf.take(3):
+  echo x
+
+# bug #3583
+proc foo(f: (iterator(): int)) =
+  for i in f(): echo i
+
+let fIt = iterator(): int = yield 70
+foo fIt
+
+# bug #5321
+
+proc lineIter*(filename: string): iterator(): string =
+  result = iterator(): string {.closure.} =
+    for line in lines(filename):
+      yield line
+
+proc unused =
+  var count = 0
+  let iter = lineIter("temp10.nim")
+  for line in iter():
+    count += 1
+
+iterator lineIter2*(filename: string): string {.closure.} =
+  var f = open(filename, bufSize=8000)
+  defer: close(f)   # <-- commenting defer "solves" the problem
+  var res = newStringOfCap(80)
+  while f.readLine(res): yield res
+
+proc unusedB =
+  var count = 0
+  for line in lineIter2("temp10.nim"):
+    count += 1
+
+# bug #5519
+import os, algorithm
+
+iterator filesIt(path: string): auto {.closure.} =
+  var files = newSeq[string]()
+  var dirs = newSeq[string]()
+  for k, p in os.walkDir(path):
+    let (_, n, e) = p.splitFile
+    if e != "":
+      continue
+    case k
+    of pcFile, pcLinkToFile:
+      files.add(n)
+    else:
+      dirs.add(n)
+  files.sort(system.cmp)
+  dirs.sort(system.cmp)
+  for f in files:
+    yield f
+
+  for d in dirs:
+    files = newSeq[string]()
+    for k, p in os.walkDir(path / d):
+      let (_, n, e) = p.splitFile
+      if e != "":
+        continue
+      case k
+      of pcFile, pcLinkToFile:
+        files.add(n)
+      else:
+        discard
+    files.sort(system.cmp)
+    let prefix = path.splitPath[1]
+    for f in files:
+      yield prefix / f
+
+# bug #13815
+when not defined(js):
+  var love = iterator: int {.closure.} =
+    yield cast[type(
+      block:
+        var a = 0
+        yield a
+        a)](0)
+
+  for i in love():
+    echo i
+else:
+  echo 0
+
+# bug #18474
+iterator pairs(): (int, int) {.closure.} =
+  for i in 1..3:
+    for j in 1..3:
+      yield (i, j)
+
+for pair in pairs():
+  echo pair