Initial implementation of monospace justification

2 files changed, 104 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..deddd48
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,12 @@
+cmake_minimum_required(VERSION 2.8)
+project(justify)
+
+set(
+	CMAKE_CXX_FLAGS
+	"${CMAKE_CXX_FLAGS} -std=c++14 -W -Wall -Wextra -Winline -pedantic"
+)
+
+add_executable(
+	justify
+	justify.cc
+)
diff --git a/justify.cc b/justify.cc
new file mode 100644
index 0000000..495dd81
--- /dev/null
+++ b/justify.cc
@@ -0,0 +1,92 @@
+#include <iostream>
+#include <string>
+#include <vector>
+#include <random>
+#include <algorithm>
+#include <cassert>
+
+class LineAccumulator {
+	static const std::size_t MAX_LENGTH = 60;
+
+	public:
+		LineAccumulator():
+			device_(),
+			length_(0),
+			tokens_(),
+			spaces_() { }
+
+		~LineAccumulator() {
+			this->discharge(false);
+		}
+
+		void operator()(const std::string& word) {
+			if ( ( this->length_ + word.length() + 1 ) > MAX_LENGTH ) {
+				this->pop_trailing_token();
+				this->discharge(true);
+			}
+
+			this->add_token(word);
+			this->add_space();
+		}
+
+	private:
+		std::random_device       device_;
+		std::size_t              length_;
+		std::vector<std::string> tokens_;
+		std::vector<std::size_t> spaces_;
+
+		void add_token(const std::string& token) {
+			this->length_ += token.length();
+			this->tokens_.emplace_back(token);
+		}
+
+		void add_space() {
+			this->add_token(" ");
+			this->spaces_.emplace_back(this->tokens_.size() - 1);
+		}
+
+		void increase_space_at(const std::size_t index) {
+			this->tokens_.at(this->spaces_[index]).append(" ");
+			++this->length_;
+		}
+
+		void pop_trailing_token() {
+			this->length_ -= this->tokens_.back().length();
+			this->tokens_.pop_back();
+			this->spaces_.pop_back();
+		}
+
+		void discharge(const bool full) {
+			if ( full ) {
+				std::mt19937 generator(this->device_());
+				std::uniform_int_distribution<> random(0, this->spaces_.size()-1);
+
+				while ( this->length_ < MAX_LENGTH ) {
+					this->increase_space_at(random(generator));
+				}
+			}
+
+			for ( const auto& token : this->tokens_ ) {
+				std::cout << token;
+			}
+
+			std::cout << '\n';
+
+			this->length_ = 0;
+			this->tokens_.clear();
+			this->spaces_.clear();
+		}
+
+};
+
+int main() {
+	std::cout.sync_with_stdio(false);
+	std::cin.sync_with_stdio(false);
+
+	LineAccumulator acc;
+	std::string     word;
+
+	while ( std::cin >> word ) {
+		acc(word);
+	}
+}