Wsrtjtyk

I just started learning common lisp and I'm trying to exercise it in a way that makes my daily work easier. In particular, I'm trying to create a set of functions and macros that takes a minimal syntax and outputs some JavaScript that I'm using often.

This is the code that I have written:

;;;; This program is aimed at creating a very high level language that writes

;;;; complex and formally correct Javascript with minimal code.



(defvar *namespace* nil)



(defmacro conc (var &body body)

  `(setf ,var (concatenate 'string output ,@body)))



(defun public-var (name value)

  (let ((output ""))

    (conc output *namespace* "." name " = " value ";")

    output))



(defmacro namespace (ns &rest contents)

  `(let ((*namespace* (concatenate 'string "window." ,ns)) (output ""))

     (conc output "(function(ns){")

     (let ((*namespace* "ns"))

       ,(loop for e in contents collect `(conc output (apply ,(first e) (list ,@(rest e))))))

     (conc output "}(" *namespace* " = " *namespace* " || {}));")

     output))

The idea is to be able to write code like this:

(namespace "namespace"

  (#'public-var "hello" "world")

  (#'public-var "something" "else"))

and get this output:

(function(ns){

  ns.hello = world;

  ns.something = else;

}(window.namespace = window.namespace || {}));

I know that I still need to work on the indentation of the output and on the line breaks, but that's not the point yet (these should be the first building blocks to abstract away more complex logics). The problem is that I'm getting this error and I can't figure out why (seriously, I already spent hours researching and trying different things):

Illegal function object:

(CONC OUTPUT (APPLY #'PUBLIC-VAR (LIST "ciao" "mondo"))).

   [Condition of type TYPE-ERROR]



Restarts:

 0: [RETRY] Retry SLIME REPL evaluation request.

 1: [*ABORT] Return to SLIME's top level.

 2: [ABORT] Abort entirely from this (lisp) process.



Backtrace:

  0: (IDE.BASE::IDE-INVOKE-DEBUGGER-FROM-NON-CG-PROCESS "Error" #<TYPE-ERROR @ #x22de54b2> T NIL NIL)

  1: (ERROR TYPE-ERROR :DATUM (CONC OUTPUT (APPLY #'PUBLIC-VAR (LIST "ciao" "mondo"))) :EXPECTED-TYPE (OR SYMBOL FUNCTION) ...)

  2: ((CONC OUTPUT (APPLY #'PUBLIC-VAR (LIST "ciao" "mondo"))))

  3: (LET ((*NAMESPACE* "ns")) ((CONC OUTPUT (APPLY #'PUBLIC-VAR #))))

  4: (LET ((*NAMESPACE* (CONCATENATE 'STRING "window." "webtrekk_dl")) (OUTPUT "")) ..)

  5: (EVAL (NAMESPACE "webtrekk_dl" (#'PUBLIC-VAR "ciao" "mondo")))

 --more--

I also tried the individual pieces. For example this:

 (let ((output ""))  (CONC OUTPUT (APPLY #'PUBLIC-VAR (LIST "ciao" "mondo"))))

works and gets me this output:

".ciao = mondo;"

Any idea what I'm doing wrong?

,(loop for e in contents collect `(conc output …))

This returns a list:

((conc output …)

 (conc output …)

 …)

A list is evaluated by applying the operator, which is the first element of the list, to the arguments.

Valid operators are only symbols or lambda forms. A conc form is invalid as an operator. Most likely you wanted something like:

(progn

  (conc output …)

  …)

As a side note, I don't know what your JavaScript output is really supposed to do. It ignores the ns parameter and sets two new global vars. This does not seem useful.