4 ms·

Agreed. Macros and reader macros ;-)

• jorgeortiz85 15y ago
  Let me know when you figure out how to statically type check those. You could publish a paper or two, I'm sure.
  • corruptmemory 15y ago
    Nemerle already does it: http://nemerle.org/macros.html http://nemerle.org/macros.html, so does Template Haskell: http://www.haskell.org/haskellwiki/Template_Haskell http://www.haskell.org/haskellwiki/Template_Haskell
  • a_strange_guy 15y ago
    You don't typecheck macros since they run at compile time. You typecheck the expanded code instead.
  • samth 15y ago
    And we did! Check out: http://blog.racket-lang.org/2011/03/languages-as-libraries-pldi-2011.html http://blog.racket-lang.org/2011/03/languages-as-libraries-p...
  • corruptmemory 15y ago
    To reiterate a point implied by other commenters: macro-expansion is a compile-time operation. If the language utilizes a typing system to help promote sound programming then the results of the expansion will be compiled in the context of type constraints - the expansion is either sound or unsound w.r.t. such constraints. To some extent there is a continuing popular schism with the idea that "strongly typed" must be synonymous with the lack of "eval", which, at least in principle, cannot be true. In fact, StandardML does have the ability to extend the environment of a program at run-time (as well as Typed Racket). All the necessary typing and meta-data is retained at run-time so that newly evaluated code is checked for type-consistency just like when the "main code" was compiled. So, not only can one expand macros at compile time and verify that the expansions are sound, one can also do the same at run-time.