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Re: how expressive are they?
--- Trevor Blackwell <firstname.lastname@example.org> wrote:
> What I'd like to see is an example of a program, in
> a language with easy
> syntax for assignment and blocks, where rewriting it
> without any
> user-defined macros would be similarly painful.
Syntax for assignment: not used
Syntax for blocks: trivial macro to redefine lambda as
Macro: pattern matching
Use: Writing XML transformations using an easy to read
and easy to write visual notation.
Exmple (from the WebIT! documentation):
Transforms a marked-up book of poems into a load of
((_ title: bt
(poem title: t poet: a tag: m
(stanza (line l1) (line l) ...) ...)
(h4:head (h4:title bt))
(h4:p) "Table of Contents:"
(h4:ul (h4:li (h4:a h4:href:
(string-append "#" m) t)) ...)
(h4:div (h4:p) (h4:a h4:name: m)
(h4:strong t) (h4:br) (h4:em a)
(list (h4:p) l1 (list (h4:br) l)
...) ...) ...))))))
Rewrite that as succinctly and clearly in
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