Explanation of macros; Haskell macros

[Lex Spoon]

Joachim Durchholz <joachim.durchholz at web.de> writes:
> This statement is wrong if left in full generality: higher-order
> functions can control quite precisely what gets evaluated when. 

They don't let you execute stuff at compile time.  If you write down:

     (parser '(    ;; ...  10 pages of BNF ... ;;
       ))


Then the parser is going to be computed at runtime.  HOF themselves
don't help you compute stuff at compile time.  (Though one can
certainly imagine a language where compile-time execution is
controlled by pragmas.)


-Lex