updated from Atlas

attic/control/adder/coroadder_deco.py

@@ -0,0 +1,96 @@
+"""
+
+    >>> adder = adder_coro()
+    >>> next(adder)
+    0
+    >>> adder.send(10)
+    10
+    >>> adder.send(20)
+    30
+    >>> adder.send(30)
+    60
+    >>> try:
+    ...     next(adder)
+    ... except StopIteration as exc:
+    ...     result = exc.value
+    ...
+    >>> result
+    Result(sum=60, terms=3, average=20.0)
+
+
+Closing a coroutine:
+
+    >>> adder = adder_coro()
+    >>> next(adder)
+    0
+    >>> adder.send(1)
+    1
+    >>> adder.send(10)
+    11
+    >>> adder.close()
+    >>> try:
+    ...     next(adder)
+    ... except StopIteration as exc:
+    ...     exc.value is None
+    ...
+    True
+
+"""
+
+import sys
+import collections
+
+
+def coroutine(func):
+    def primed_coroutine(*args, **kwargs):
+        coro = func(*args, **kwargs)
+        next(coro)
+        return coro
+    return primed_coroutine
+
+
+Result = collections.namedtuple('Result', 'sum terms average')
+
+
+@coroutine
+def adder_coro(initial=0):
+    total = initial
+    num_terms = 0
+    while True:
+        try:
+            term = yield total
+        except GeneratorExit:
+            break
+        if term is None:
+            break
+        total += term
+        num_terms += 1
+    return Result(total, num_terms, total/num_terms)
+
+
+def prompt():
+    while True:
+        try:
+            term = float(input('+ '))
+        except ValueError:
+            break
+        yield term
+
+
+def main(get_terms):
+    adder = adder_coro()
+    for term in get_terms:
+        adder.send(term)
+    try:
+        adder.send(None)
+    except StopIteration as exc:
+        result = exc.value
+    print(result)
+
+
+if __name__ == '__main__':
+    if len(sys.argv) > 1:
+        get_terms = (float(n) for n in sys.argv[1:])
+    else:
+        get_terms = prompt()
+    main(get_terms)