minh thu wrote: > 2009/10/7 Günther Schmidt <gue.schm...@web.de>: >>> I've informally argued that a true DSL -- separate from a good API -- >>> should have semantic characteristics of a language: binding forms, >>> control structures, abstraction, composition. Some have type systems. >>> >> >> That is one requirement that confuses me, abstraction. >> >> I thought of DSLs as "special purpose" languages, ie. you give your DSL >> everything it needs for that purpose. >> >> Why would it also need the ability to express even further abstractions, >> it is supposed to *be* the abstraction. > > Programming abstractions at the DSL level, not to further abstract > what the DSL covers. > > Functions, for instance, are typical abstraction means offered by > programming languages. Even if your language is specific to some > domain, being able to create your own functions, and not only rely on > those provided by the DSL implementation, is important. > > Imagine a (E)DSL for 3D programming (e.g. shading language): the > language is designed to fit well the problem (e.g. in this case, 3D > linear algebra, color operations, ...) but you'll agree it would be a > shame to not be able to provide your own functions.
But isn't one of the advantages of an _E_DSL that we can use the host language (Haskell) as a meta or macro language for the DSL? I would think that this greatly reduces the need to provide abstraction facilities /inside/ the DSL. In fact most existing (and often cited examples of) EDSLs in Haskell do not provide abstraction. Cheers Ben _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
