Common Lisp: Getting the documentation string of a macro

Question

In SBCL, I can get the documentation string for a function with something like this: ``` (documentation #'mapcar t) ``` However, I don't understand how to get the documentation string for a macro. For example, given the macro: ``` (defmacro with-lines-in-file ((line filename) &body body) "Runs body for each line in the file specified by filename." (let ((file (gensym))) `(with-open-file (,file ,filename) (do ((,line (read-line ,file nil) (read-line ,file nil))) ((null ,line) nil) ,@body)))) ``` I'm not able to retrieve the documentation string. I don't understand the CLHS. As you can see below, the CLHS worked great for obtaining the documentation string for a function. ``` documentation (x function) (doc-type (eql 't)) ``` However, the bit for obtaining the documentation string from a macro doesn't seem to work for me: ``` documentation (x symbol) (doc-type (eql 'compiler-macro)) ``` In the context of my macro, I'm interpreting the above CLHS bit to mean this: ``` (documentation 'wit…

Accepted Answer

The standard says for the Common Lisp function documentation:

function If x is a function name, returns the documentation string of the function, macro, or special operator whose name is x.

The three operator types one can retrieve documentation from, with the argument `function` are thus:

- function

- macro

- special operator

Remember, in Common Lisp an operator can only be one of those at a time.

Example

```
CL-USER> (defmacro foomacro () "foo macro" '(foo))
FOOMACRO
CL-USER> (documentation 'foomacro 'function)
"foo macro"
```

Macros are not compiler macros. Those are defined by DEFINE-COMPILER-MACRO.

Common Lisp: Getting the documentation string of a macro

Solution

Problem