cdr-cells + !
;
-: caar car car ;
-: cadr cdr car ;
-: cdar car cdr ;
-: cddr cdr cdr ;
-
: nil 0 nil-type ;
: nil? nil-type istype? ;
quote-symbol tagged-list? ;
: quote-body ( quote-obj -- quote-body-obj )
- cadr ;
+ cdr car ;
: quasiquote? ( obj -- obj bool )
quasiquote-symbol tagged-list? ;
;
defer eval-quasiquote-item
-: eval-quasiquote-list ( env obj -- res )
- nil? if
- 2swap 2drop exit
- then
-
+: eval-quasiquote-pair ( env obj -- res )
2over 2over ( env obj env obj )
- cdr recurse
- -2rot car ( cdritems env objcar )
+ cdr eval-quasiquote-item
+
+ -2rot car ( cdritem env objcar )
unquote-splicing? if
eval-unquote ( cdritems caritem )
;
:noname ( env obj )
+ nil? if
+ 2swap 2drop exit
+ then
+
unquote? if
eval-unquote exit
then
pair-type istype? if
- eval-quasiquote-list exit
+ eval-quasiquote-pair exit
then
2swap 2drop
endcase
;
+( Simply evaluates the given procedure with expbody as its argument. )
: macro-expand ( proc expbody -- result )
2swap
2dup procedure-body ( expbody proc procbody )