Quasiquote: template with unquote and splicing.
quasiQuasiquote: template with unquote and splicing.
Compile-on-first-use: the template is compiled to a pair/lit/append tree on first evaluation, then cached.
Returns: ANY — Expanded template with substitutions
Examples:
(def x 1) (quasi (a ,x b)) => ('a 1 'b)