From 8d65f74d9f4ee7af834fb295355d11ccfa884a8f Mon Sep 17 00:00:00 2001
From: Eric Mertens <emertens@galois.com>
Date: Fri, 4 Nov 2022 11:36:30 -0700
Subject: [PATCH] Run

---
 day05.cpp                           | 14 +++---------
 day09.cpp                           | 14 +++---------
 day11.cpp                           | 33 +++++++++++++----------------
 lib/include/Overload.hpp            |  7 ++++++
 lib/include/intcode/Interpreter.hpp | 19 ++++++++++++++++-
 lib/include/intcode/intcode.hpp     |  6 ++----
 6 files changed, 48 insertions(+), 45 deletions(-)
 create mode 100644 lib/include/Overload.hpp

diff --git a/day05.cpp b/day05.cpp
index 92f1dc4..0929a21 100644
--- a/day05.cpp
+++ b/day05.cpp
@@ -8,17 +8,9 @@ namespace {
 
 auto Compute(Machine machine, ValueType d) -> ValueType {
   ValueType last_output = -1;
-  while (std::visit(overloaded{
-    [](Halt) { return false; },
-    [d, &machine](Input arg) {
-      arg.pos = d;
-      return true;
-    },
-    [&last_output](Output arg) {
-      last_output = arg.val;
-      return true;
-    }},
-    Step(machine)));
+  Run(machine,
+    [=]() { return d; },
+    [&](auto o) { last_output = o; });
   return last_output;
 }
 
diff --git a/day09.cpp b/day09.cpp
index 0779504..844e262 100644
--- a/day09.cpp
+++ b/day09.cpp
@@ -8,17 +8,9 @@ namespace {
 
 auto Compute(Machine machine, ValueType d) -> ValueType {
   ValueType output = -1;
-  while (std::visit(overloaded{
-    [](Halt) { return false; },
-    [d](Input arg) {
-      arg.pos = d;
-      return true;
-    },
-    [&output](Output arg) {
-      output = arg.val;
-      return false;
-    }},
-    Step(machine)));
+  Run(machine,
+    [=](){ return d; },
+    [&](auto o) { output = o; });
   return output;
 }
 
diff --git a/day11.cpp b/day11.cpp
index 7f98690..9caf0f2 100644
--- a/day11.cpp
+++ b/day11.cpp
@@ -18,26 +18,23 @@ auto Compute(Machine machine, ValueType start)
   ValueType dx {0};
   ValueType dy {-1};
 
-  for (;;) {
-    auto effect = Step(machine);
+  bool next_color = true;
 
-    if (std::holds_alternative<Halt>(effect)) {
-      return paint;
-    }
+  Run(machine,
+    [&]() { return paint[here]; },
+    [&](auto o) {
+      if (next_color) {
+        paint[here] = o;
+      } else {
+        std::swap(dx, dy);
+        (o ? dx : dy) *= -1;
+        here.first += dx;
+        here.second += dy;
+      }
+      next_color = !next_color;
+    });
 
-    std::get<Input>(effect).pos = paint[here];
-    paint[here] = std::get<Output>(Step(machine)).val;
-    auto dir = std::get<Output>(Step(machine)).val;
-
-    std::swap(dx, dy);
-    if (dir) {  
-      dx = -dx;
-    } else {
-      dy = -dy;
-    }
-    here.first += dx;
-    here.second += dy;
-  }
+  return paint;
 }
 
 auto Draw(std::ostream & out, std::map<Coord, ValueType> image) {
diff --git a/lib/include/Overload.hpp b/lib/include/Overload.hpp
new file mode 100644
index 0000000..9dcdaae
--- /dev/null
+++ b/lib/include/Overload.hpp
@@ -0,0 +1,7 @@
+#ifndef OVERLOAD_HPP_
+#define OVERLOAD_HPP_
+
+template <class... Ts> struct overloaded : Ts... { using Ts::operator()...; };
+template <class... Ts> overloaded(Ts...) -> overloaded<Ts...>;
+
+#endif
diff --git a/lib/include/intcode/Interpreter.hpp b/lib/include/intcode/Interpreter.hpp
index bb8967a..e3ca67a 100644
--- a/lib/include/intcode/Interpreter.hpp
+++ b/lib/include/intcode/Interpreter.hpp
@@ -1,8 +1,10 @@
 #ifndef INTCODE_INTERPRETER_HPP_
 #define INTCODE_INTERPRETER_HPP_
 
-#include "Machine.hpp"
+#include <variant>
 
+#include <intcode/Machine.hpp>
+#include <Overload.hpp>
 namespace intcode {
 
 struct Input {
@@ -21,6 +23,21 @@ struct BadInstruction : public std::runtime_error {
   explicit BadInstruction(char const* what);
 };
 
+template <class Fin, class Fout>
+auto Run(Machine & machine, Fin input, Fout output) -> void {
+  while (std::visit(overloaded{
+    [](Halt) { return false; },
+    [&](Input arg) {
+      arg.pos = input();
+      return true;
+    },
+    [&](Output arg) {
+      output(arg.val);
+      return true;
+    }},
+    Step(machine)));
+}
+
 } // namespace
 
 #endif
diff --git a/lib/include/intcode/intcode.hpp b/lib/include/intcode/intcode.hpp
index a56803b..7506259 100644
--- a/lib/include/intcode/intcode.hpp
+++ b/lib/include/intcode/intcode.hpp
@@ -1,11 +1,9 @@
-#ifndef INTCODE_HPP_
+#ifndef INTCODE_INTCODE_HPP_
 #define INTCODE_INTCODE_HPP_
 
 #include <intcode/Machine.hpp>
 #include <intcode/Parser.hpp>
 #include <intcode/Interpreter.hpp>
-
-template <class... Ts> struct overloaded : Ts... { using Ts::operator()...; };
-template <class... Ts> overloaded(Ts...) -> overloaded<Ts...>;
+#include <Overload.hpp>
 
 #endif