| Maintainer | simons@cryp.to |
|---|---|
| Stability | experimental |
| Portability | portable |
| Safe Haskell | Safe |
| Language | Haskell98 |
Text.XML.HaXml.Verbatim
Description
The preferred method for rendering a Document or single Content
is by using the pretty printing facility defined in Pretty.
Pretty-printing does not work well for cases, however, where the
formatting in the XML document is significant. Examples of this
case are XHTML's <pre> tag, Docbook's <literallayout> tag,
and many more.
Theoretically, the document author could avoid this problem by
wrapping the contents of these tags in a <![CDATA[...]]> section,
but often this is not practical, for instance when the
literal-layout section contains other elements. Finally, program
writers could manually format these elements by transforming them
into a literal string in their CFliter, etc., but this is
annoying to do and prone to omissions and formatting errors.
As an alternative, this module provides the function verbatim,
which will format XML Content as a String while retaining the
formatting of the input document unchanged.
Known problems:
- HaXml's parser eats line feeds between two tags.
Attributes should be formatted by making them an instance ofVerbatimas well, but since anAttributeis just a tuple, not a full data type, the helper functionverbAttrmust be used instead.CMiscis not yet supported.MarkupDecls, which contain no content, are formatted as<element-name/>, even if they were not defined as being of typeEMPTY. In XML this perfectly alright, but in SGML it is not. Those, who wish to useverbatimto format parts of say an HTML page will have to (a) replace problematic elements byliterals before runningverbatimor (b) use a second search-and-replace stage to fix this.
Documentation
This class promises that the function verbatim knows how to
format this data type into a string without changing the
formatting.
Instances
| Verbatim Char # | |
Defined in Text.XML.HaXml.Verbatim | |
| Verbatim AttValue # | |
Defined in Text.XML.HaXml.Verbatim | |
| Verbatim Reference # | |
Defined in Text.XML.HaXml.Verbatim | |
| Verbatim a => Verbatim [a] # | |
Defined in Text.XML.HaXml.Verbatim | |
| Verbatim (Content i) # | |
Defined in Text.XML.HaXml.Verbatim | |
| Verbatim (Element i) # | |
Defined in Text.XML.HaXml.Verbatim | |
| (Verbatim a, Verbatim b) => Verbatim (Either a b) # | |
Defined in Text.XML.HaXml.Verbatim | |
verbAttr :: Attribute -> String #
This is a helper function is required because Haskell does not
allow to make an ordinary tuple (like Attribute) an instance of a
class. The resulting output will preface the actual attribute with
a single blank so that lists of Attributes can be handled
implicitly by the definition for lists of Verbatim data types.