Clojure: finding out if a collection is seq-able

Question

So there's list?, seq?, vector?, map? and so on to determine what type of collection the argument is.

What's a good way of telling the difference between

• a map (i.e. something that contains key-value pairs)
• a collection (i.e. something that contains values)
• a non collection value like a string.

Is there a better way than

#(or (seq? %) (list? %) etc)

Answer 1

using seq? is about as concise and clean as it gets.

clojure.contrib.core defines:

seqable?
    function
    Usage: (seqable? x)
    Returns true if (seq x) will succeed, false otherwise.

http://clojure.github.com/clojure-contrib/core-api.html

it does what you proposed with one big or statement of

• already a seq
• an instance of clojure.lang.Seqable
• nil
• instance of Iterable
• an array
• a string
• instance of java.util.Map

Answer 2

Let's not forget about sequential?:

user=> (sequential? [])
true
user=> (sequential? '())
true
user=> (sequential? {:a 1})
false
user=> (sequential? "asdf")
false