Why comma is special?

[Kazimir Majorinc]

I noted that comma cannot be part of the symbol; it appears identifier



x,y



is understood like it is the sequence of three symbols



x , y



Is it intentional?

[Jeff]

Yes, it is intentional.  The comma is a newlisp idiom for establishing local variables in a function:

Code Select Expand

(define (foo param , a b c)
  ;; here, a, b, and c are nil
  (println "Hello world"))

[DrDave]

From the manual

Some of the example programs contain functions that use a comma to separate the parameters into two groups. This is not a special syntax of newLISP, but rather a visual trick. The comma is a symbol just like any other symbol.

[Jeff]

It is a symbol and may be set, but the comma is recognized individually by the parser and is not a valid character in other symbols.