cpp-enigma: enigma/rotor.cpp comparison

Initial commit. Working on the rotor class.

comparison

equal deleted inserted replaced

--1:000000000000
+:74ebb2150658
+// Copyright (C) 2012 by Brian Neal.
+// This file is part of Cpp-Enigma, the Enigma Machine simulation.
+// Cpp-Enigma is released under the MIT License (see License.txt).
+//
+// rotor.cpp - Implementation file for the rotor class.
+#include <set>
+#include <array>
+#include <algorithm>
+#include "rotor.h"
+using namespace enigma;
+namespace
+{
+const char* const ucase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+const std::set<char> ucase_set(ucase, ucase + 26);
+}
+rotor::rotor(const char* name, const char* wiring, int ring_setting, const char* stepping)
+: rotor_name(name),
+wiring_str(wiring),
+ring_setting(ring_setting),
+pos(0),
+rotations(0)
+{
+// check wiring length
+if (wiring_str.size() != 26)
+{
+throw rotor_error("invalid wiring length");
+}
+// ensure wiring contains only uppercase letters & every char must appear
+// exactly once:
+std::array<int, 26> letter_counts {{ 0 }};
+for (int i = 0; i < 26; ++i)
+{
+const char c(wiring_str[i]);
+if (ucase_set.find(c) == ucase_set.end())
+{
+throw rotor_error("invalid wiring");
+}
+++letter_counts[c - 'A'];
+}
+if (std::find_if(letter_counts.begin(),
+letter_counts.end(),
+[](int n) { return n != 1; }) != letter_counts.end())
+{
+throw rotor_error("invalid wiring; duplicate letter");
+}
+}

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