Args must be a sequence (list, vector, or string) or a primitive Java array. (This is an extension over standard Scheme, which requires that args be a list.) Calls the proc (which must be a procedure), using as arguments the arg1... values plus all the elements of args.

Same as (proc arg1 ...), unless proc and all the following arguments are compile-time constants. (That is: They are either constant, or symbols that have a global binding and no lexical binding.) In that case, proc is applied to the arguments at compile-time, and the result replaces the constant-fold form. If the application raises an exception, a compile-time error is reported. For example:

(constant-fold vector 'a 'b 'c)

is equivalent to (quote #(a b c)), assuming vector has not been re-bound.