Merge pull request #2730 from ethereum/indented-writer

Introduce IndentedWriter

3 files changed, 207 insertions, 0 deletions

diff --git a/libdevcore/IndentedWriter.cpp b/libdevcore/IndentedWriter.cpp
new file mode 100644
index 00000000..96aaf0fa
--- /dev/null
+++ b/libdevcore/IndentedWriter.cpp
@@ -0,0 +1,65 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @date 2017
+ * Indented text writer.
+ */
+
+#include <libdevcore/IndentedWriter.h>
+#include <libdevcore/Assertions.h>
+
+using namespace std;
+using namespace dev;
+
+string IndentedWriter::format() const
+{
+	string result;
+	for (auto const& line: m_lines)
+		result += string(line.indentation * 4, ' ') + line.contents + "\n";
+	return result;
+}
+
+void IndentedWriter::newLine()
+{
+	if (!m_lines.back().contents.empty())
+		m_lines.push_back({ string(), m_lines.back().indentation });
+}
+
+void IndentedWriter::indent()
+{
+	newLine();
+	m_lines.back().indentation++;
+}
+
+void IndentedWriter::unindent()
+{
+	newLine();
+	assertThrow(m_lines.back().indentation > 0, IndentedWriterError, "Negative indentation.");
+	m_lines.back().indentation--;
+}
+
+void IndentedWriter::add(string const& _str)
+{
+	m_lines.back().contents += _str;
+}
+
+void IndentedWriter::addLine(string const& _line)
+{
+	newLine();
+	add(_line);
+	newLine();
+}
diff --git a/libdevcore/IndentedWriter.h b/libdevcore/IndentedWriter.h
new file mode 100644
index 00000000..4ddd87ed
--- /dev/null
+++ b/libdevcore/IndentedWriter.h
@@ -0,0 +1,67 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @date 2017
+ * Indented text writer.
+ */
+
+#pragma once
+
+#include <vector>
+#include <string>
+
+#include <libdevcore/Exceptions.h>
+
+namespace dev
+{
+
+DEV_SIMPLE_EXCEPTION(IndentedWriterError);
+
+class IndentedWriter
+{
+public:
+	explicit IndentedWriter(): m_lines(std::vector<Line>{{std::string(), 0}}) {}
+
+	// Returns the formatted output.
+	std::string format() const;
+
+	// Go one indentation level in.
+	void indent();
+
+	// Go one indentation level out.
+	void unindent();
+
+	// Add text.
+	void add(std::string const& _str);
+
+	// Add text with new line.
+	void addLine(std::string const& _line);
+
+	// Add new line.
+	void newLine();
+
+private:
+	struct Line
+	{
+		std::string contents;
+		unsigned indentation;
+	};
+
+	std::vector<Line> m_lines;
+};
+
+}
diff --git a/test/libdevcore/IndentedWriter.cpp b/test/libdevcore/IndentedWriter.cpp
new file mode 100644
index 00000000..a694aa1b
--- /dev/null
+++ b/test/libdevcore/IndentedWriter.cpp
@@ -0,0 +1,75 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * Unit tests for IndentedWriter.
+ */
+
+#include <libdevcore/IndentedWriter.h>
+
+#include "../TestHelper.h"
+
+using namespace std;
+
+namespace dev
+{
+namespace test
+{
+
+BOOST_AUTO_TEST_SUITE(IndentedWriterTest)
+
+BOOST_AUTO_TEST_CASE(empty)
+{
+	IndentedWriter iw;
+	BOOST_CHECK_EQUAL(iw.format(), "\n");
+}
+
+BOOST_AUTO_TEST_CASE(new_lines)
+{
+	IndentedWriter iw;
+	iw.newLine();
+	BOOST_CHECK_EQUAL(iw.format(), "\n");
+}
+
+BOOST_AUTO_TEST_CASE(text_without_newline)
+{
+	IndentedWriter iw;
+	iw.add("Hello World");
+	BOOST_CHECK_EQUAL(iw.format(), "Hello World\n");
+}
+
+BOOST_AUTO_TEST_CASE(text_with_newline)
+{
+	IndentedWriter iw;
+	iw.addLine("Hello World");
+	BOOST_CHECK_EQUAL(iw.format(), "Hello World\n\n");
+}
+
+BOOST_AUTO_TEST_CASE(indent)
+{
+	IndentedWriter iw;
+	iw.addLine("Hello");
+	iw.indent();
+	iw.addLine("World");
+	iw.unindent();
+	iw.addLine("and everyone else");
+	BOOST_CHECK_EQUAL(iw.format(), "Hello\n    World\nand everyone else\n\n");
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+}
+}