diff options
author | Nick Wellnhofer <wellnhofer@aevum.de> | 2018-09-14 12:48:10 +0200 |
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committer | Nick Wellnhofer <wellnhofer@aevum.de> | 2018-09-14 12:48:10 +0200 |
commit | 0707ada63bf5662c34b8f8fab60291840377217c (patch) | |
tree | de3c87cc4a68aa1f6ee1391d236608fe4115360e /tools | |
parent | 63c675f9acead1171a2881fbbf12ddc6c3cc82d1 (diff) |
XSLT stylesheet to convert cmark XML back to Commonmark
Initial version of an XSLT stylesheet that converts the XML format
produced by `cmark -t xml` back to Commonmark.
Fixes #264
Diffstat (limited to 'tools')
-rw-r--r-- | tools/xml2md.xsl | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/tools/xml2md.xsl b/tools/xml2md.xsl new file mode 100644 index 0000000..2fc7ce1 --- /dev/null +++ b/tools/xml2md.xsl @@ -0,0 +1,308 @@ +<?xml version="1.0" encoding="UTF-8"?> + +<!-- + +xml2md.xsl +========== + +This XSLT stylesheet transforms the cmark XML format back to Commonmark. +Since the XML output is lossy, a lossless MD->XML->MD roundtrip isn't +possible. The XML->MD->XML roundtrip should produce the original XML, +though. + +HTML blocks and inlines aren't supported. + +Example usage with xsltproc: + + cmark -t xml doc.md | xsltproc -novalid xml2md.xsl - + +--> + +<xsl:stylesheet + version="1.0" + xmlns:xsl="http://www.w3.org/1999/XSL/Transform" + xmlns:md="http://commonmark.org/xml/1.0"> + +<xsl:output method="text" encoding="utf-8"/> + +<!-- Generic templates --> + +<xsl:template match="/ | md:document | md:list"> + <xsl:apply-templates select="md:*"/> +</xsl:template> + +<xsl:template match="md:*"> + <xsl:message>Unsupported element '<xsl:value-of select="local-name()"/>'</xsl:message> +</xsl:template> + +<xsl:template match="md:*" mode="indent"/> + +<!-- Indent blocks --> + +<xsl:template match="md:*" mode="indent-block"> + <xsl:if test="preceding-sibling::md:*"> + <xsl:if test="not(ancestor::md:list[1][@tight='true'])"> + <xsl:apply-templates select="ancestor::md:*" mode="indent"/> + <xsl:text> </xsl:text> + </xsl:if> + <xsl:apply-templates select="ancestor::md:*" mode="indent"/> + </xsl:if> +</xsl:template> + +<!-- Heading --> + +<xsl:template match="md:heading"> + <xsl:apply-templates select="." mode="indent-block"/> + <xsl:value-of select="substring('###### ', 7 - @level)"/> + <xsl:apply-templates select="md:*"/> + <xsl:text> </xsl:text> +</xsl:template> + +<!-- Paragraph --> + +<xsl:template match="md:paragraph"> + <xsl:apply-templates select="." mode="indent-block"/> + <xsl:apply-templates select="md:*"/> + <xsl:text> </xsl:text> +</xsl:template> + +<!-- Thematic break --> + +<xsl:template match="md:thematic_break"> + <xsl:apply-templates select="." mode="indent-block"/> + <xsl:text>*** </xsl:text> +</xsl:template> + +<!-- List --> + +<xsl:template match="md:list"> + <xsl:apply-templates select="." mode="indent-block"/> + <xsl:apply-templates select="md:*"/> +</xsl:template> + +<xsl:template match="md:item"> + <xsl:apply-templates select="." mode="indent-block"/> + <xsl:choose> + <xsl:when test="../@type = 'bullet'">-</xsl:when> + <xsl:when test="../@type = 'ordered'"> + <xsl:value-of select="../@start + position() - 1"/> + <xsl:choose> + <xsl:when test="../@delim = 'period'">.</xsl:when> + <xsl:when test="../@delim = 'paren'">)</xsl:when> + </xsl:choose> + </xsl:when> + </xsl:choose> + <xsl:text> </xsl:text> + <xsl:apply-templates select="md:*"/> +</xsl:template> + +<xsl:template match="md:item" mode="indent"> + <xsl:choose> + <xsl:when test="../@type = 'bullet'"> + <xsl:text> </xsl:text> + </xsl:when> + <xsl:when test="../@type = 'ordered'"> + <xsl:text> </xsl:text> + </xsl:when> + </xsl:choose> +</xsl:template> + +<!-- Block quote --> + +<xsl:template match="md:block_quote"> + <xsl:apply-templates select="." mode="indent-block"/> + <xsl:text>> </xsl:text> + <xsl:apply-templates select="md:*"/> +</xsl:template> + +<xsl:template match="md:block_quote" mode="indent"> + <xsl:text>> </xsl:text> +</xsl:template> + +<!-- Code block --> + +<xsl:template match="md:code_block"> + <xsl:apply-templates select="." mode="indent-block"/> + <!-- TODO: Longer delimiter if text contains ``` --> + <xsl:text>```</xsl:text> + <xsl:value-of select="@info"/> + <xsl:text> </xsl:text> + <xsl:call-template name="indent-lines"> + <xsl:with-param name="code" select="."/> + </xsl:call-template> + <xsl:apply-templates select="ancestor::md:*" mode="indent"/> + <xsl:text>```</xsl:text> + <xsl:text> </xsl:text> +</xsl:template> + +<!-- Inline HTML --> + +<xsl:template match="md:html_block"> + <xsl:apply-templates select="." mode="indent-block"/> + <xsl:value-of select="substring-before(., ' ')"/> + <xsl:text> </xsl:text> + <xsl:call-template name="indent-lines"> + <xsl:with-param name="code" select="substring-after(., ' ')"/> + </xsl:call-template> +</xsl:template> + +<!-- Indent multiple lines --> + +<xsl:template name="indent-lines"> + <xsl:param name="code"/> + <xsl:if test="contains($code, ' ')"> + <xsl:apply-templates select="ancestor::md:*" mode="indent"/> + <xsl:value-of select="substring-before($code, ' ')"/> + <xsl:text> </xsl:text> + <xsl:call-template name="indent-lines"> + <xsl:with-param name="code" select="substring-after($code, ' ')"/> + </xsl:call-template> + </xsl:if> +</xsl:template> + +<!-- Text --> + +<xsl:template match="md:text"> + <xsl:variable name="t" select="string(.)"/> + <xsl:variable name="first" select="substring($t, 1, 1)"/> + <xsl:variable name="marker-check" select="translate(substring($t, 1, 10), '0123456789', '')"/> + <xsl:choose> + <!-- Escape ordered list markers --> + <xsl:when test="starts-with($marker-check, '.') and $first != '.'"> + <xsl:value-of select="substring-before($t, '.')"/> + <xsl:text>\.</xsl:text> + <xsl:call-template name="escape-text"> + <xsl:with-param name="text" select="substring-after($t, '.')"/> + </xsl:call-template> + </xsl:when> + <xsl:when test="starts-with($marker-check, ')') and $first != ')'"> + <xsl:value-of select="substring-before($t, ')')"/> + <xsl:text>\)</xsl:text> + <xsl:call-template name="escape-text"> + <xsl:with-param name="text" select="substring-after($t, ')')"/> + </xsl:call-template> + </xsl:when> + <!-- Escape leading block characters --> + <xsl:when test="contains('-+>#=~', $first)"> + <xsl:text>\</xsl:text> + <xsl:value-of select="$first"/> + <xsl:call-template name="escape-text"> + <xsl:with-param name="text" select="substring($t, 2)"/> + </xsl:call-template> + </xsl:when> + <!-- Otherwise --> + <xsl:otherwise> + <xsl:call-template name="escape-text"> + <xsl:with-param name="text" select="$t"/> + </xsl:call-template> + </xsl:otherwise> + </xsl:choose> +</xsl:template> + +<!-- Breaks --> + +<xsl:template match="md:softbreak"> + <xsl:text> </xsl:text> + <xsl:apply-templates select="ancestor::md:*" mode="indent"/> +</xsl:template> + +<xsl:template match="md:linebreak"> + <xsl:text> </xsl:text> + <xsl:apply-templates select="ancestor::md:*" mode="indent"/> +</xsl:template> + +<!-- Emphasis --> + +<xsl:template match="md:emph"> + <xsl:text>*</xsl:text> + <xsl:apply-templates select="md:*"/> + <xsl:text>*</xsl:text> +</xsl:template> + +<xsl:template match="md:strong"> + <xsl:text>**</xsl:text> + <xsl:apply-templates select="md:*"/> + <xsl:text>**</xsl:text> +</xsl:template> + +<!-- Inline code --> + +<xsl:template match="md:code"> + <xsl:call-template name="escape-code"> + <xsl:with-param name="text" select="string(.)"/> + </xsl:call-template> +</xsl:template> + +<xsl:template name="escape-code"> + <xsl:param name="text"/> + <xsl:param name="delim" select="'`'"/> + + <xsl:choose> + <xsl:when test="contains($text, $delim)"> + <xsl:call-template name="escape-code"> + <xsl:with-param name="text" select="$text"/> + <xsl:with-param name="delim" select="concat($delim, '`')"/> + </xsl:call-template> + </xsl:when> + <xsl:otherwise> + <xsl:value-of select="$delim"/> + <xsl:value-of select="$text"/> + <xsl:value-of select="$delim"/> + </xsl:otherwise> + </xsl:choose> +</xsl:template> + +<!-- Links and images --> + +<xsl:template match="md:link | md:image"> + <xsl:if test="self::md:image">!</xsl:if> + <xsl:text>[</xsl:text> + <xsl:apply-templates select="md:*"/> + <xsl:text>](</xsl:text> + <xsl:call-template name="escape-text"> + <xsl:with-param name="text" select="string(@destination)"/> + <xsl:with-param name="escape" select="'()'"/> + </xsl:call-template> + <xsl:if test="string(@title)"> + <xsl:text> "</xsl:text> + <xsl:call-template name="escape-text"> + <xsl:with-param name="text" select="string(@title)"/> + <xsl:with-param name="escape" select="'"'"/> + </xsl:call-template> + <xsl:text>"</xsl:text> + </xsl:if> + <xsl:text>)</xsl:text> +</xsl:template> + +<!-- Inline HTML --> + +<xsl:template match="md:html_inline"> + <xsl:value-of select="."/> +</xsl:template> + +<!-- Escape text --> + +<xsl:template name="escape-text"> + <xsl:param name="text"/> + <xsl:param name="escape" select="'*_`<[]&'"/> + + <xsl:variable name="trans" select="translate($text, $escape, '\\\\\\\')"/> + <xsl:choose> + <xsl:when test="contains($trans, '\')"> + <xsl:variable name="safe" select="substring-before($trans, '\')"/> + <xsl:variable name="l" select="string-length($safe)"/> + <xsl:value-of select="$safe"/> + <xsl:text>\</xsl:text> + <xsl:value-of select="substring($text, $l + 1, 1)"/> + <xsl:call-template name="escape-text"> + <xsl:with-param name="text" select="substring($text, $l + 2)"/> + <xsl:with-param name="escape" select="$escape"/> + </xsl:call-template> + </xsl:when> + <xsl:otherwise> + <xsl:value-of select="$text"/> + </xsl:otherwise> + </xsl:choose> +</xsl:template> + +</xsl:stylesheet> |