I'm reading Cloujure in Action as an introduction to Clojure and,
although, I understand a keyword can be used as a function I don't
understand the difference between:
(ns org.currylogic.damages.http.expenses
(:require [clojure.data.json :as json-lib]
The ns form is a macro that takes a special syntax and always uses the
keyword form, as you have in your first example. Your second example is
incorrect; I'd be surprised if it even ran.
The reason for this is to make it clear that you're not executing the
require function directly, but instead
On 03/07/2014 18:36, James Reeves wrote:
The reason for this is to make it clear that you're not executing the
require function directly, but instead passing options to the ns form.
I don't understand not executing the require function directly.
I've also seen the when function called as
I believe you might have seen :when in the binding vector of either a for
or deseq form. Their special usage is documented
here: http://clojure.github.io/clojure/clojure.core-api.html#clojure.core/for
In any event, James explained the distinction quite well. Macros are often
used to create
Keywords can be used as a function with a map, so the keyword will search
for itself in the map. Take a look at
http://clojure.org/data_structures#Data%20Structures-Keywords
In the case of the ns form, as James pointed out, what is happening is
not a function call. ns is a macro and as such that
One thing to note is that while it's true keywords can be used as
functions they can only really do one thing, which is get values from
maps. That is to say, the keyword-function :foo is equivalent to the
function #(get % foo). The function :foo has no relationship with the
function foo, if it
