(clojure.data.xml/emit-str (element :e {:attr "x"} (element :e1) (element :e2)))
; Generates:
; "<?xml version=\"1.0\" encoding=\"UTF-8\"?><e attr=\"x\"><e1></e1><e2></e2></t>"

; However, I need to generate elements from a data str, so I've something like:

(clojure.data.xml/emit-str (element :e
                                    {:attr "x"}
                                    (for [e '[:e1 :e2]]
                                         (element e))))

; which results in...
; IllegalArgumentException No implementation of method: :emit-element of protocol:
; #'clojure.data.xml/Emit found for class: clojure.lang.LazySeq  clojure.core/-cache-
; protocol-fn (core_deftype.clj:527)
;
; I.e., (element) doesn't destructure the result of the (for)
; I can see this if I use clojure.data.xml/emit instead of emit-str:

(pprint (element :e
                 {:attr "x"}
                 (for [e '[:e1 :e2]]
                      (element e))))

; This outputs:
{:tag :e,
 :attrs {:attr "x"},
 :content
 (({:tag :e1, :attrs {}, :content ()}
   {:tag :e2, :attrs {}, :content ()}))}

; which has the :e1 and :e2 elements in a superfluous seq