From 24fb0c87f4dc8b416ab0069816fb8fb199120e96 Mon Sep 17 00:00:00 2001
From: Aleksey Lobanov <i@likemath.ru>
Date: Sun, 8 Dec 2019 23:54:34 +0300
Subject: [PATCH] Added negation for single argument

---
 al_function.hpp | 52 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/al_function.hpp b/al_function.hpp
index dcb77be..026e4cb 100644
--- a/al_function.hpp
+++ b/al_function.hpp
@@ -2,10 +2,27 @@
 #define _AL_FUNCTION_HPP
 
 #include <cassert>
+#include <cstdint>
 
 #include <limits>
 #include <string>
 
+
+uint32_t ones      = 0b11111111111111111111111111111111;
+
+uint32_t mask_1    = 0b01010101010101010101010101010101;
+uint32_t remains_1 = 0b00000000000000000000000000000001;
+uint32_t shift_1   = 1;
+uint32_t mask_2    = 0b00110011001100110011001100110011;
+uint32_t remains_2 = 0b00000000000000000000000000000011;
+uint32_t shift_2   = 2;
+uint32_t mask_3    = 0b00001111000011110000111100001111;
+uint32_t remains_3 = 0b00000000000000000000000000001111;
+uint32_t shift_3   = 4;
+uint32_t mask_4    = 0b00000000111111110000000011111111;
+uint32_t remains_4 = 0b00000000000000000000000011111111;
+uint32_t shift_4   = 8;
+
 template<class STORAGE, size_t VALUES_COUNT>
 class Function {
     public:
@@ -59,6 +76,41 @@ class Function {
             return _function_values == other._function_values;
         }
 
+        Function var_negation(STORAGE var_index) {
+            // var_index should be in 1..VARS_COUNT
+            STORAGE mask, remains, shift;
+            switch (var_index) {
+                case 1:
+                    mask = mask_1;
+                    remains = remains_1;
+                    shift = shift_1;
+                    break;
+                case 2:
+                    mask = mask_2;
+                    remains = remains_2;
+                    shift = shift_2;
+                    break;
+                case 3:
+                    mask = mask_3;
+                    remains = remains_3;
+                    shift = shift_3;
+                    break;
+                case 4:
+                    mask = mask_4;
+                    remains = remains_4;
+                    shift = shift_3;
+                    break;
+                default:
+                    assert(false);
+
+            }
+
+            STORAGE first_part = (_function_values & (~mask)) >> shift;
+            STORAGE second_part = (_function_values & mask) << shift;
+            return Function(first_part | second_part);
+
+        }
+
         STORAGE value() const {
             return _function_values;
         }