list filter idom => idiot

doh..well I solved my exceedingly simple problem => private: [%file1.r %file2.html %file3.jpeg] files: sort read %. public: copy [] foreach file files [ either find privatefile [print "private viewing by appointments only"] [append public file] ] ; now render linked list of public files foreach file public [ print rejoin [{<a href="} file {">} file {</a><br>}] ] What other rebol idioms do you recommend for filtering items listed in one block from those in another? thanks ./Jason

From: "Jason Cunliffe" ...

> What other rebol idioms do you recommend for filtering items listed in one

> from those in another?

Hi Jason, << What other rebol idioms do you recommend for filtering items listed in one block from those in another? >> EXCLUDE is good, as Scott pointed out. REMOVE-EACH is handy too, but it's only in the betas at this time. private: [%file1.r %file2.html %file3.jpeg] files: append sort read %. [%file1.r %file2.html %file3.jpeg] remove-each file files [find private file] ; now render linked list of public files foreach file files [ print rejoin [{<a href="} file {">} file {</a><br>}] ] Here's something I started tinkering with a while back, which you may find useful. Kind of a klunky interface IMO, but that's a good excercise for the student as they say. :) split: func [ {Applies each predicate to each element in blk and returns a block of blocks with items partitioned by which predicate they match. If an item doesn't match any predicate, it will be in the last block. Only handles simple args right now.} series [series!] predicates [block!] args /local match result p ][ result: copy [] loop add length? predicates 1 [append/only result copy []] repeat el series [ match: false repeat i length? predicates [ ; Have to use a temp var for the predicate here, in addition to ; the result of the predicate call. p: get predicates/:i match: p :el either block? args [args/:i][args] if match [ append result/:i :el break ] ] if not match [ append last result :el ] ] result ] ;split [1 2 3.4 5.6 7 8.9] [integer? decimal?] none ;split [1 2 3.4 5.6 7 8.9 0 100] [lesser? greater?] [3 7] ;split [1 2 3.4 5.6 7 8.9 0 100] [lesser? greater?] 3 HTH! --Gregg

Hi Jason, ------------------------ You wrote : -------------------------------------

> << What other rebol idioms do you recommend for filtering items listed in > one block from those in another? >>

Thanks everyone.. EXCLUDE REMOVE-EACH INTERSECT DIFFERENCE Lots to explore. I like these much better than any nested either/ifs. For some reason, whenever I use even a simple either/if (more than one level deep), I feel a little guilty/clumsy. It seems rebol has better more 'forward' moving idioms. But I forget them sometmies when I jump from soemthing like Flash Actionscript [JavaScript]. REBOL: reverse FORTH! cheers ./Jason

I like these much better than any nested either/ifs.

> For some reason, whenever I use even a simple either/if (more than one

> deep), I feel a little guilty/clumsy. > It seems rebol has better more 'forward' moving idioms. > But I forget them sometmies when I jump from soemthing like Flash

> [JavaScript].