1 files changed, 117 insertions, 0 deletions
diff --git a/tests/iter/titer8.nim b/tests/iter/titer8.nim
new file mode 100644
index 000000000..7b6d7b6de
--- /dev/null
+++ b/tests/iter/titer8.nim
@@ -0,0 +1,117 @@
+discard """
+  output: '''tada
+1
+2
+3
+ta da1 1
+1 2
+1 3
+2 1
+2 2
+2 3
+3 1
+3 2
+3 3
+0
+1
+2
+a1: A
+a2: A
+a1: B
+a2: B
+a1: C
+a2: C
+a1: D'''
+"""
+# Test first class iterator:
+
+import strutils
+
+iterator tokenize2(s: string, seps: set[char] = Whitespace): tuple[
+  token: string, isSep: bool] {.closure.} =
+  var i = 0
+  while i < s.len:
+    var j = i
+    if s[j] in seps:
+      while j < s.len and s[j] in seps: inc(j)
+      if j > i:
+        yield (substr(s, i, j-1), true)
+    else:
+      while j < s.len and s[j] notin seps: inc(j)
+      if j > i:
+        yield (substr(s, i, j-1), false)
+    i = j
+
+iterator count3(): int {.closure.} =
+  yield 1
+  yield 2
+  yield 3
+
+for word, isSep in tokenize2("ta da", WhiteSpace):
+  if not isSep:
+    stdout.write(word)
+echo ""
+
+proc inProc() =
+  for c in count3():
+    echo c
+
+  for word, isSep in tokenize2("ta da", WhiteSpace):
+    stdout.write(word)
+
+  for c in count3():
+    for d in count3():
+      echo c, " ", d
+
+
+inProc()
+
+iterator count0(): int {.closure.} =
+  # note: doesn't require anything in its closure (except 'state')
+  yield 0
+
+iterator count2(): int {.closure.} =
+  # note: requires 'x' in its closure
+  var x = 1
+  yield x
+  inc x
+  yield x
+
+# a first class iterator has the type 'proc {.closure.}', but maybe
+# it shouldn't:
+proc invoke(iter: iterator(): int {.closure.}) =
+  for x in iter(): echo x
+
+invoke(count0)
+invoke(count2)
+
+
+# simple tasking:
+type
+  TTask = iterator (ticker: int)
+
+iterator a1(ticker: int) {.closure.} =
+  echo "a1: A"
+  yield
+  echo "a1: B"
+  yield
+  echo "a1: C"
+  yield
+  echo "a1: D"
+
+iterator a2(ticker: int) {.closure.} =
+  echo "a2: A"
+  yield
+  echo "a2: B"
+  yield
+  echo "a2: C"
+
+proc runTasks(t: varargs[TTask]) =
+  var ticker = 0
+  while true:
+    let x = t[ticker mod t.len]
+    if finished(x): break
+    x(ticker)
+    inc ticker
+
+runTasks(a1, a2)