textwrap.dedent
これは、可能な限り模倣しようとする長めのソリューションです。最初の行はそのまま残され、インデントされないことが期待されます。( doctest -csharpを使用して、doctests に基づいて単体テストを生成できます。)
/// <summary>
/// Imitates the Python's
/// <a href="https://docs.python.org/3/library/textwrap.html#textwrap.dedent">
/// <c>textwrap.dedent</c></a>.
/// </summary>
/// <param name="text">Text to be dedented</param>
/// <returns>array of dedented lines</returns>
/// <code doctest="true">
/// Assert.That(Dedent(""), Is.EquivalentTo(new[] {""}));
/// Assert.That(Dedent("test me"), Is.EquivalentTo(new[] {"test me"}));
/// Assert.That(Dedent("test\nme"), Is.EquivalentTo(new[] {"test", "me"}));
/// Assert.That(Dedent("test\n me"), Is.EquivalentTo(new[] {"test", " me"}));
/// Assert.That(Dedent("test\n me\n again"), Is.EquivalentTo(new[] {"test", "me", " again"}));
/// Assert.That(Dedent(" test\n me\n again"), Is.EquivalentTo(new[] {" test", "me", " again"}));
/// </code>
private static string[] Dedent(string text)
{
var lines = text.Split(
new[] {"\r\n", "\r", "\n"},
StringSplitOptions.None);
// Search for the first non-empty line starting from the second line.
// The first line is not expected to be indented.
var firstNonemptyLine = -1;
for (var i = 1; i < lines.Length; i++)
{
if (lines[i].Length == 0) continue;
firstNonemptyLine = i;
break;
}
if (firstNonemptyLine < 0) return lines;
// Search for the second non-empty line.
// If there is no second non-empty line, we can return immediately as we
// can not pin the indent.
var secondNonemptyLine = -1;
for (var i = firstNonemptyLine + 1; i < lines.Length; i++)
{
if (lines[i].Length == 0) continue;
secondNonemptyLine = i;
break;
}
if (secondNonemptyLine < 0) return lines;
// Match the common prefix with at least two non-empty lines
var firstNonemptyLineLength = lines[firstNonemptyLine].Length;
var prefixLength = 0;
for (int column = 0; column < firstNonemptyLineLength; column++)
{
char c = lines[firstNonemptyLine][column];
if (c != ' ' && c != '\t') break;
bool matched = true;
for (int lineIdx = firstNonemptyLine + 1; lineIdx < lines.Length;
lineIdx++)
{
if (lines[lineIdx].Length == 0) continue;
if (lines[lineIdx].Length < column + 1)
{
matched = false;
break;
}
if (lines[lineIdx][column] != c)
{
matched = false;
break;
}
}
if (!matched) break;
prefixLength++;
}
if (prefixLength == 0) return lines;
for (var i = 1; i < lines.Length; i++)
{
if (lines[i].Length > 0) lines[i] = lines[i].Substring(prefixLength);
}
return lines;
}