Return all lines of the SourceString as a list of SourceLine's.

def get_all_lines(self):
        """Return all lines of the SourceString as a list of SourceLine's."""
        output = []
        line = []
        lineno = 1
        for char in self.string:
            line.append(char)
            if char == '\n':
                output.append(SourceLine(''.join(line), lineno))
                line = []
                lineno += 1
        if line:
            output.append(SourceLine(''.join(line), lineno))

        return output