@@ -501,20 +501,36 @@ ; could bind index instead of gensym +(def walk (seq func) + (if alist.seq + ((afn (l) + (when (acons l) + (func (car l)) + (self (cdr l)))) seq) + (isa seq 'table) + (maptable (fn (k v) (func (list k v))) seq) + ; else + (for i 0 (- (len seq) 1) + (func (seq i))))) + (mac each (var expr . body) - (w/uniq (gseq gf gv) - `(let ,gseq ,expr - (if (alist ,gseq) - ((rfn ,gf (,gv) - (when (acons ,gv) - (let ,var (car ,gv) ,@body) - (,gf (cdr ,gv)))) - ,gseq) - (isa ,gseq 'table) - (maptable (fn ,var ,@body) - ,gseq) - (for ,gv 0 (- (len ,gseq) 1) - (let ,var (,gseq ,gv) ,@body)))))) + `(walk ,expr (fn (,var) ,@body))) + +; ; old definition of 'each. possibly faster, but not extendable. +; (mac each (var expr . body) +; (w/uniq (gseq gf gv) +; `(let ,gseq ,expr +; (if (alist ,gseq) +; ((rfn ,gf (,gv) +; (when (acons ,gv) +; (let ,var (car ,gv) ,@body) +; (,gf (cdr ,gv)))) +; ,gseq) +; (isa ,gseq 'table) +; (maptable (fn ,var ,@body) +; ,gseq) +; (for ,gv 0 (- (len ,gseq) 1) +; (let ,var (,gseq ,gv) ,@body)))))) ; (nthcdr x y) = (cut y x). arc.arc @@ -250,10 +250,14 @@ " Repeats the `body' `n' times. See also [[for]] [[forlen]] [[n-of]] " + walk + " Calls `func' on each element of `seq' for side-effects. + See also [[map]] [[each]] " + each " Performs `body' for each element of the sequence returned by `expr', with each element assigned to `var'. - See also [[forlen]] [[on]] [[map]] [[ontable]] " + See also [[walk]] [[forlen]] [[on]] [[map]] [[ontable]] " cut " Returns a subsequence of the given `seq'. If `end' is negative, help/arc.arc 470644baea39fdbb99a9fb434b03d0a2c44076d9 Michael Arntzenius daekharel@gmail.com http://github.com/nex3/arc/commit/517b00282898992aa99db1371751a520469476e4 517b00282898992aa99db1371751a520469476e4 2009-08-23T11:19:05-07:00 2009-08-23T11:19:05-07:00 Refactor 'each into 'walk (fn) and 'each (mac) This may be slower, but it follows the maxim to never create a macro where a function will do. Also, it permits extending 'walk to change the semantics of 'each. 1c7bb47772f9ab00bf0b27fb340074009faadd84 Michael Arntzenius daekharel@gmail.com