[[Abstract syntax]] written using prefix constructor terms can become rather unreadable when patterns become large. Therefore it is attractrive to write [[transformation rules]] using the concrete syntax of
the object language instead of its abstract syntax. For example, to write
<verbatim>
  PlusZero :
	  |[ e + 0 ]| -> |[ e ]|
</verbatim>
instead of 
<verbatim>
  PlusZero :
	  Plus(e, Int(0)) -> e
</verbatim>

Starting with StrategoRelease08 concrete syntax is supported by Stratego. For a full account of this new feature and its implementation see the paper [[Meta Programming with Concrete Object Syntax]].

---------

The techniques for handling embedded syntax in a meta-language have now been generalized and are
implemented in the =parse-cs= tool in the [[concrete syntax package]] in the StrategoXT distribution.
This tool has been used in the embedding of concrete syntax in Prolog implemented in the [[Prolog tools]]
package.

-- Main.EelcoVisser - 28 Nov 2003

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CategoryConcreteObjectSyntax