How does Clojure loop form works?

Question

I am new to Clojure an Functional Programming both. I tried my best, understanding the loop construct.

I can use it, I can look at a code written with it and tell the output but what I dont understand is,How does it work ?

is it same as writing an anonymous function with parameters and then keeping recur at the tail with same arity and new values ?

is it an inbuilt macro or something for it ?

Answer 1

Actually, loop is not a function or a macro. It is a special form. It works just like let (which is also a special form) except that it acts as a target for recur.

One way to differentiate functions, macros, and special forms is to examine how their arguments are evaluated:

• Function arguments are always evaluated, and then the results are passed to the function.
• Macro arguments are not evaluated until the macro expands to a new unevaluated form.
• Special form arguments are not evaluated when passed, but the special form may or may not choose to evaluate them internally.