reader can read inputs and emit a pretty steady signal

src/input.py

@@ -1,17 +0,0 @@
-class Input:
-   def __init__(self, reader):
-      self.reader = reader
-
-   def get(self):
-      return self.reader.read()
-
-class StdinReader:
-   def read(self):
-      return input()
-
-class FileReader:
-   def __init__(self, path):
-      self.f = open(path, "r")
-
-   def read(self):
-      return self.f.readline()

src/main.py

@@ -1,5 +1,11 @@
+import reader
+import writer
+
 def main():
-   raise Exception("not impl")
+   r = reader.Reader(reader.StdinReader())
+   w = writer.Writer()
+   for line in r.read():
+      w.write(line)
 
 if __name__ == "__main__":
    main()

src/reader.py

@@ -0,0 +1,63 @@
+import threading
+import queue
+import time
+import sys
+import select
+
+__interval__ = .1
+
+class Reader:
+   def __init__(self, reader):
+      self.reader = reader
+
+   def read(self):
+      q = queue.Queue(maxsize=1)
+
+      class async_reader(threading.Thread):
+         def __init__(self, q, foo):
+            threading.Thread.__init__(self)
+            self.q = q
+            self.foo = foo
+            self.stopping = False
+
+         def stop(self):
+            self.stopping = True
+
+         def run(self):
+            while not self.stopping:
+               try:
+                  self.q.put_nowait(self.foo())
+               except queue.Full:
+                  pass
+               time.sleep(__interval__/2.0)
+
+      reader = async_reader(q, self.reader.read)
+      reader.start()
+      try:
+         while not reader.stopping:
+            try:
+               yield q.get(timeout=__interval__)
+            except queue.Empty:
+               yield None
+               pass
+      except KeyboardInterrupt as e:
+         reader.stop()
+         reader.join()
+         raise e
+
+class StdinReader:
+   def read(self):
+      try:
+         if select.select([sys.stdin,],[],[],__interval__/2.0)[0]:
+            line = sys.stdin.readline()
+            return line.strip()
+      except Exception as e:
+         pass
+      return None
+
+class FileReader:
+   def __init__(self, path):
+      self.f = open(path, "r")
+
+   def read(self):
+      return self.f.readline()

src/writer.py

@@ -1,10 +1,11 @@
 import time
 
-class Output:
+class Writer:
    def __init__(self):
-      self.previous = None
+      self.previous = Line(None)
 
-   def write(self, latest):
+   def write(self, v):
+      latest = Line(v)
       chosen = Line.choose(self.previous, latest)
       if chosen.v != self.previous.v:
          print(chosen)