#!/usr/bin/python
'''Word wrap code; a version of the following, by Aristotle Pagaltzis:

<xsl:template name="wrap-string" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:param name="str" />
    <xsl:param name="wrap-col" />
    <xsl:param name="break-mark" />
    <xsl:param name="pos" select="0" />
    <xsl:choose>

        <xsl:when test="contains( $str, ' ' )">
            <xsl:variable name="first-word" select="substring-before( $str, ' ' )" />
            <xsl:variable name="pos-now" select="$pos + 1 + string-length( $first-word )" />
            <xsl:choose>

                <xsl:when test="$pos-now >= $wrap-col">
                    <xsl:copy-of select="$break-mark" />
                    <xsl:call-template name="wrap-string">
                        <xsl:with-param name="str" select="$str" />
                        <xsl:with-param name="wrap-col" select="$wrap-col" />
                        <xsl:with-param name="break-mark" select="$break-mark" />
                        <xsl:with-param name="pos" select="0" />
                    </xsl:call-template>
                </xsl:when>

                <xsl:otherwise>
                    <xsl:value-of select="$first-word" />
                    <xsl:text> </xsl:text>
                    <xsl:call-template name="wrap-string">
                        <xsl:with-param name="str" select="substring-after( $str, ' ' )" />
                        <xsl:with-param name="wrap-col" select="$wrap-col" />
                        <xsl:with-param name="break-mark" select="$break-mark" />
                        <xsl:with-param name="pos" select="$pos-now" />
                    </xsl:call-template>
                </xsl:otherwise>

            </xsl:choose>
        </xsl:when>

        <xsl:otherwise>
            <xsl:if test="$pos + string-length( $str ) >= $wrap-col">
                <xsl:copy-of select="$break-mark" />
            </xsl:if>
            <xsl:value-of select="$str" />
        </xsl:otherwise>

    </xsl:choose>
</xsl:template>
'''
                    
def wrap_string(output, str_, wrap_col, break_mark, pos=0):
    if ' ' in str_:
        first_word = str_[:str_.index(' ')]
        pos_now = pos + 1 + len(first_word)

        if pos_now > wrap_col:
            output(break_mark)
            wrap_string(output, str_, wrap_col, break_mark, 0)
        else:
            output(first_word)
            str_ = str_[str_.index(' ')+1:]
            wrap_string(output, str_, wrap_col, break_mark, pos_now)
    else:
        if pos + len(str_) >= wrap_col:
            output(break_mark)
        output(str_)