#2844 6.0.3: The `dt (n1,n2)` syntax makes it hard to use programmatically defined dashtype

[Ilya Zakharevich]

I want to use a calculated dashtype, but while dt k works, dt (k+1) does not. (With the message

                                                      ^
         expecting comma

)

And AFAIK, in other situation complicated expressions in gnuplot⸣s plot commands “should be” (?) put in parentheses. In some cases one can manage with abominations like k>15?1:k==6?2:0 — but sometimes the difficulties are not surmountable.

Is there a need to prohibit lists of length 1 (as in dt (k+1) — meaning the same as without the parens)?

(Knowing fine details of Perl tokenizer) I can see that dt +(k+1) works too. So as a stopgap, one could just document such syntax…