A buffer that keeps track of the current indentation level. It abstracts the need for formatting code to thread the current indentation everywhere, and also ensures that blank lines do not accidentally get filled with the current indentation, thus yielding trailing whitespace in the output.

Appends the input string to a buffer. If the buffer is at the start of a new line, then the current indentation is inserted.

Starts a new line in the buffer, but does not append any indentation. This will only happen if a string is appended before the buffer moves to the next line.

Increase the current indentation by one level.

Decrease the current indentation by one level.

Create a new buffer with the specified initial capacity.

Retrieve the contents of the buffer as a string.