Factored out from the UEF implementation the concept of being a tape that has a queue of pending pulses and manages that queue.

Storage/Tape/PulseQueuedTape.cpp

@@ -0,0 +1,61 @@
+//
+//  PulseQueuedTape.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 16/07/2017.
+//  Copyright © 2017 Thomas Harte. All rights reserved.
+//
+
+#include "PulseQueuedTape.hpp"
+
+using namespace Storage::Tape;
+
+PulseQueuedTape::PulseQueuedTape() : pulse_pointer_(0) {}
+
+bool PulseQueuedTape::is_at_end() {
+	return is_at_end_;
+}
+
+void PulseQueuedTape::set_is_at_end(bool is_at_end) {
+	is_at_end_ = is_at_end;
+}
+
+void PulseQueuedTape::clear() {
+	queued_pulses_.clear();
+	pulse_pointer_ = 0;
+}
+
+bool PulseQueuedTape::empty() {
+	return queued_pulses_.empty();
+}
+
+void PulseQueuedTape::emplace_back(Tape::Pulse::Type type, Time length) {
+	queued_pulses_.emplace_back(type, length);
+}
+
+Tape::Pulse PulseQueuedTape::silence() {
+	Pulse silence;
+	silence.type = Pulse::Zero;
+	silence.length.length = 1;
+	silence.length.clock_rate = 1;
+	return silence;
+}
+
+Tape::Pulse PulseQueuedTape::virtual_get_next_pulse() {
+	if(is_at_end_) {
+		return silence();
+	}
+
+	if(pulse_pointer_ == queued_pulses_.size()) {
+		clear();
+		get_next_pulses();
+
+		if(is_at_end_ || pulse_pointer_ == queued_pulses_.size()) {
+			return silence();
+		}
+	}
+
+	size_t read_pointer = pulse_pointer_;
+	pulse_pointer_++;
+	return queued_pulses_[read_pointer];
+}