Confusing behaviour of CLOG

[aykaramba]

GOAL: I want to pass in a form, perform a logic test and if the test is T return the form, otherwise return NIL.

PROBLEM: I am confused by the behaviour of CLOG. The simplest possible example of the confusing behaviour:

1. Let's say that we have a function as follows:

(defun foo-perform-test  (this-form )
  )

We are leaving this function empty just for the purposes of testing and comparison.

2. Let's say we have a LET form in CLOG as follows:

(let* ((container (create-div body :content "hello")))
    (foo (create-div container :content " there"))
    (foo '(create-div container :content " also over there")))

3. Let's do some tests and compare:

a) In the Slime console we get the following results:

(foo (+ 2 2)) ==> NIL
(foo '(+ 2 2)) ==> NIL

b) However, in CLOG, the behavior with the above code is slightly different:

(foo (create-div container :content "there"))  ==> This renders the div!!!
(foo '(create-div container :content "there")) ==> Does not render, as expected.

What is going on here to allow (foo (create-div container :content "there")) to render in CLOG? I was expecting NIL and for the form to not render.

PURPOSE OF THE TEST: I want to create a function that can get a form passed in, have the function perform a logic test and if T return the passed in form back to clog so that it can rendering.

Any ideas on why CLOG is rendering the passed unquoted form in the example above?

[rabbibotton]

A quoted form is just that a quoted form that is never executed. While you could use eval of the quoted form passed in, consider a macro.

[aykaramba]

Thanks for the follow up. I have it working with a macro. Thank you kindly.