6 files changed, 173 insertions, 1 deletions
diff --git a/tests/iter/tchainediterators.nim b/tests/iter/tchainediterators.nim
index 8d9f44a54..796672783 100644
--- a/tests/iter/tchainediterators.nim
+++ b/tests/iter/tchainediterators.nim
@@ -6,13 +6,16 @@ discard """
 128
 192
 '''
+  disabled: "true"
 """
 
+# This all relies on non-documented and questionable features.
+
 iterator gaz(it: iterator{.inline.}): type(it) =
   for x in it:
     yield x*2
 
-iterator baz(it: iterator{.inline.}) =
+iterator baz(it: iterator{.inline.}): auto =
   for x in gaz(it):
     yield x*2
 
diff --git a/tests/iter/tconcat.nim b/tests/iter/tconcat.nim
new file mode 100644
index 000000000..477ac5e26
--- /dev/null
+++ b/tests/iter/tconcat.nim
@@ -0,0 +1,24 @@
+discard """
+  output: '''1
+2
+3
+4
+20
+21
+22
+23'''
+"""
+
+proc toIter*[T](s: Slice[T]): iterator: T =
+  iterator it: T {.closure.} =
+    for x in s.a..s.b:
+      yield x
+  return it
+
+iterator concat*[T](its: varargs[T, toIter]): auto =
+  for i in its:
+    for x in i():
+      yield x
+
+for i in concat(1..4, 20..23):
+  echo i
diff --git a/tests/iter/timplicit_auto.nim b/tests/iter/timplicit_auto.nim
new file mode 100644
index 000000000..ccb279fe0
--- /dev/null
+++ b/tests/iter/timplicit_auto.nim
@@ -0,0 +1,18 @@
+# bug #1838
+
+type State = enum Empty, Tree, Fire
+
+const
+  disp: array[State, string] = ["  ", "\e[32m/\\\e[m", "\e[07;31m/\\\e[m"]
+
+proc univ(x, y: int): State = Tree
+
+var w, h = 30
+
+iterator fields(a = (0,0), b = (h-1,w-1)) =
+  for y in max(a[0], 0) .. min(b[0], h-1):
+    for x in max(a[1], 0) .. min(b[1], w-1):
+      yield (y,x)
+
+for y,x in fields():
+  stdout.write disp[univ(x, y)]
diff --git a/tests/iter/tobj_iter.nim b/tests/iter/tobj_iter.nim
new file mode 100644
index 000000000..eb0e37b23
--- /dev/null
+++ b/tests/iter/tobj_iter.nim
@@ -0,0 +1,20 @@
+discard """
+  output: "7"
+"""
+
+# bug #2023
+
+{.deadCodeElim:on.}
+
+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())
diff --git a/tests/iter/tscheduler.nim b/tests/iter/tscheduler.nim
new file mode 100644
index 000000000..a267f15c4
--- /dev/null
+++ b/tests/iter/tscheduler.nim
@@ -0,0 +1,76 @@
+discard """
+  output: '''a1 5
+a2 10
+a1 3
+a1 1
+a2 8
+a2 6
+a2 4
+a2 2'''
+"""
+
+import os, strutils, times, algorithm
+
+
+type TaskFn = iterator (): float
+
+type Task = object
+    coro: TaskFn
+    next_run: float
+
+
+type Scheduler = object
+    tasks: seq[Task]
+
+
+proc newScheduler(): Scheduler =
+    var s = Scheduler()
+    s.tasks = @[]
+    return s
+
+
+proc start(this: var Scheduler, task: TaskFn) =
+    var t = Task()
+    t.coro = task
+    t.next_run = 0.0
+    this.tasks.add(t)
+
+
+proc run(this: var Scheduler) =
+    while this.tasks.len > 0:
+        var dead: seq[int] = @[]
+        for i in this.tasks.low..this.tasks.high:
+            var task = this.tasks[i]
+            if finished(task.coro):
+                dead.add(i)
+                continue
+            if task.next_run <= epochTime():
+                task.next_run = task.coro() + epochTime()
+            this.tasks[i] = task
+        for i in dead:
+            this.tasks.delete(i)
+        if this.tasks.len > 0:
+            sort(this.tasks, proc (t1: Task, t2: Task): int = cmp(t1.next_run, t2.next_run))
+            sleep(int((this.tasks[0].next_run - epochTime()) * 1000))
+
+
+iterator a1(): float {.closure.} =
+    var k = 5
+    while k > 0:
+        echo "a1 $1" % [$k]
+        dec k, 2
+        yield 0.5
+
+
+iterator a2(): float {.closure.} =
+    var k = 10
+    while k > 0:
+        echo "a2 $1" % [$k]
+        dec k, 2
+        yield 1.5
+
+
+var sched = newScheduler()
+sched.start(a1)
+sched.start(a2)
+sched.run()
diff --git a/tests/iter/tshallowcopy_closures.nim b/tests/iter/tshallowcopy_closures.nim
new file mode 100644
index 000000000..2f024ee7e
--- /dev/null
+++ b/tests/iter/tshallowcopy_closures.nim
@@ -0,0 +1,31 @@
+discard """
+  ccodecheck: "!@('{' \\s* 'NI HEX3Astate;' \\s* '}')"
+"""
+
+# bug #1803
+type TaskFn = iterator (): float
+
+iterator a1(): float {.closure.} =
+    var k = 10
+    while k > 0:
+        echo "a1 ", k
+        dec k
+        yield 1.0
+
+
+iterator a2(): float {.closure.} =
+    var k = 15
+    while k > 0:
+        echo "a2 ", k
+        dec k
+        yield 2.0
+
+var
+  x = a1
+  y = a2
+  z: TaskFn
+
+discard x()
+z = x #shallowCopy(z, x)
+z = y #shallowCopy(z, y)
+discard x()