common lisp features in SKILL

 Hi Tashah,

First, I am not familiar with "cSuppliedP" for a function argument.  I think that you would have to code this sort of behaviour yourself, something like the following:

(defun myFunc ( a b @optional (c 'undef))
  (setq cSuppliedP nil)
  (if (eq c 'undef)
    (setq c 10)
    (setq cSuppliedP t)
  )
  ; ... rest of procedure, c either has default value and cSuppliedP is nil
  ; or it has the supplied value and cSuppliedP is true
)

As far as I know "push" and "pop" work with lists but are not documented, pushing and popping from a dpl interferes with the initial "nil" of the dpl list structure, so I don't think these work as they stand.  I should be relatively easy to implement this behaviour though?  For formatted print output you can use printf. 

I apologise if this does not help much, but I am familiar with SKILL but unfamiliar with common lisp.  There is a "Scheme/SKILL++ Equivalents Table" in the documentation, this may help a little?

Regards,

Lawrence.

Thanks Lawence, it was quite useful. So, I guess my problem is when I use "Cadence SKILL API Finder", I am not finding these functions. As you said push and pop is supported, but they do not appear in search results.

'undef is the new thing that I learned, thanks.

 Hi Tashah,

I should point out that "'undef" has no special meaning, it is just a value that the user is unlikely to supply, so when they do supply a value you can detect it.  Unfortunately this method would spoil the type template, for example if the type template for the function was "nnn" to indicate that a, b and c are to be supplied as numbers, then the default value 'undef of c would break this.  In this case you could just test in the code to see if the value of "c" is the same as the default - it does not detect whether the default was supplied though (would you need to detect this?), for example:

(defun myFunc (a b @optional (c 10) "nnn")
  (if (equal c 10) (setq cSuppliedP nil) (setq cSuppliedP t))
  ; .. rest of code
)

The type template is a very useful feature, make use of it if you can.  If the user supplies something other than a number type (float or integer are acceptable here) then the function fails with a clear message. Other characters that can be used for the type template are things like "t" for a string, "l" for a list, "g" for general (anything), "x" for an integer (or 'fixnum'), "f" for a floating point ('flonum').

I hope that this helps you.

Regards,

Lawrence.

That is very valuable function. Thanks a lot.