: nested-ifs ( item quot-seq inner-truth-quot all-false-quot -- ... ) '[ _ dupd 1&& [ @ ] [ @ ] if ] call ; ! Example: { 1 2 } { [ sequence? ] [ first 1 = ] } [ drop t ] [ drop f ] nested-ifs ! ----- \ index { [ sequence? ] [ length 4 >= ] } [ dup length zip >hashtable '[ _ at ] ] [ drop f ] nested-ifs 1 define-transform ! is it an improvement over this?: \ index [ dup sequence? [ dup length 4 >= [ dup length zip >hashtable '[ _ at ] ] [ drop f ] if ] [ drop f ] if ] 1 define-transform ! heh, the connotation may be wrong, I'm not sure what that code does. ! the idea is that case style is easier to see than nested ifs, but nested ifs may be faster or less repetitive (less checks in inner branches).