Refactored with Interpreter.pipe_from

day07.py

@@ -1,49 +1,52 @@
 #!/usr/bin/env python3
 
-from intcode import Interpreter, makeIO, Singleton, Halted
+from intcode import Interpreter, SingletonIO 
 from itertools import permutations
+from lib import memoize
 
 stack_size = 5
 fst_amp_input = 0
 
-IO = makeIO(list, Singleton)
 
 def preproc(puzzle_input):
     program = list(map(int, puzzle_input.split(',')))
-    amp = lambda : Interpreter(program, IO)
-    return amp
+    def make_amp(phase):
+        amp = Interpreter(program, SingletonIO)
+        amp.eval(phase)
+        return amp
+    return make_amp
 
 
 
-def partI(amp):
+def partI(make_amp):
+    @memoize
+    def run_amp(phase, amp_in):
+        amp = make_amp(phase)
+        return amp.run(amp_in)
+
     phase_range = range(stack_size)
     best = 0 
 
     for perm in permutations(phase_range):
         amp_in = fst_amp_input
         for phase in perm:
-            amp_in = amp().run([phase, amp_in])
+            amp_in = run_amp(phase, amp_in)
         best = max(amp_in, best)
     return best
    
-def partII(amp):
+def partII(make_amp):
     phase_range = range(5, 10)
     best = 0 
 
     for perm in permutations(phase_range):
-        amps = [amp() for _ in range(stack_size)]
-        for p, a in zip(perm, amps):
-            a.eval([p])
-
-        amp_in = fst_amp_input
-        while True:
-            try:
-                for a in amps:
-                    amp_in = a.eval([amp_in])
-            except Halted:
-                break
+        amps = list(map(make_amp, perm))
+        for prev, amp in zip(amps, amps[1:]):
+            amp.pipe_from(prev)
+        
+        amp.write(fst_amp_input)
+        for amp_in in amp:
+            amp.write(amp_in)
         best = max(amp_in, best)
-    
     return best
 
 from main import Tests

intcode.py

@@ -9,6 +9,9 @@ class WaitForInput(Exception):
 class Halted(Exception):
     pass
 
+class PipeError(Exception):
+    pass
+
 class defaultlist(list):
     """Default list class. Allows writing and reading out of bounds."""
     def __init__(self, lst, val_factory):
@@ -207,6 +210,21 @@ class Interpreter(object):
             pass
         return self.IO.flush()
 
+    def pipe_from(self, other):
+        class Output(Exception):
+            pass
+        def raise_output(o):
+            raise Output(o)
+        other.comp.out_f = raise_output
+        def get_input():
+            try:
+                other.run()
+                raise PipeError
+            except Output as o:
+                return int(str(o))
+        self.comp.in_f = get_input
+        self.IO.write = other.IO.write
+
 
     def copy(self):
         memory = self.memory.copy()

lib.py

@@ -1,5 +1,15 @@
 #!/usr/bin/env python3
 
+def memoize(f):
+    cache = dict()
+    def memf(*args):
+        key = tuple(args)
+        if key not in cache:
+            cache[key] = f(*args)
+        return cache[key]
+    return memf
+
+
 class Graph(dict):
     nodes = dict.keys