Mailing List Archive: 49091 messages
  • Home
  • Script library
  • AltME Archive
  • Mailing list
  • Articles Index
  • Site search

[REBOL] Macro - function problems

From: robbo1mark::aol::com at: 12-Mar-2002 12:57

Hi everybody, Iam looking for help to write a MACRO transformation function. Iam looking for the guru's on this list to help me with some lexical scoping and "Hygienic" problems I've been having with regards to my 'MACRO function. My MACRO function takes three arguments which are these 'name [word!] args [block!] body [block!] and should construct a transformer function which allows named words to produce an executable expression (ie a paren! or alternatively a 'DOES function) which can be bound to a word and properly handles (lexically substitutes) the correct arguments and which can also allow for nestable macro expressions! here are some simple examples of what I mean
>> MACRO nil ['word] [set word zero] >> nil b
== (set 'b zero) ; or func [] [set 'b zero]
>> source b
b: (set 'b zero) ; or func [] [set 'b zero]
>> b
== 0
>> source b
b: 0 and another example
>> MACRO printer ['word 'value] [print value] >> printer test "Hello"
== (print "Hello) ; or func [] [print "Hello"]
>> source test
test: (print "Hello") ; or func [] [print "Hello"]
>> test
>> test
Hello Obviously you could imagine more advanced and / or exotic examples. I can produce these functions individually making use of things like 'compose, 'to-paren and 'quote which is defined thus, quote: func ['val] [:val] However the deeper / more general solution and lexical intricacies escape me and thus I need your help. Thanks in advance, mark Dickson