"""
outstream.py

The outstream module defines the OutStream class.
"""

import sys

#-----------------------------------------------------------------------

class OutStream:

    """
    An OutStream object wraps around a text file or sys.stdout, and
    supports writing to that stream.
    """

    #-------------------------------------------------------------------

    def __init__(self, f=None):
        """
        Construct self to wrap around a stream. If f is provided, then
        the stream is a file of that name.  Otherwise the stream is
        standard output.
        """
        if f is None:
            self._stream = sys.stdout
        else:
            if sys.hexversion < 0x03000000:
                self._stream = open(f, 'w')
            else:
                self._stream = open(f, 'w', encoding='utf-8')

    #-------------------------------------------------------------------

    def writeln(self, x=''):
        """
        Write x and an end-of-line mark to the stream wrapped by self.
        """
        if sys.hexversion < 0x03000000:
            x = unicode(x)
            x = x.encode('utf-8')
        else:
            x = str(x)
        self._stream.write(x)
        self._stream.write('\n')
        self._stream.flush()

    #-------------------------------------------------------------------

    def write(self, x=''):
        """
        Write x to the stream wrapped by self.
        """
        if (sys.hexversion < 0x03000000):
            x = unicode(x)
            x = x.encode('utf-8')
        else:
            x = str(x)
        self._stream.write(x)
        self._stream.flush()

    #-------------------------------------------------------------------

    def writef(self, fmt, *args):
        """
        Write each element of args to the stream wrapped by self.
        Use the format specified by string fmt.
        """
        x = fmt % args
        if sys.hexversion < 0x03000000:
            x = unicode(x)
            x = x.encode('utf-8')
        self._stream.write(x)
        self._stream.flush()

    #-------------------------------------------------------------------

    def __del__(self):
        """
        Close the stream wrapped by self.
        """
        self._stream.close()