Trying out a new formatting style

General
1

For today I have switched to this style:

This comes from Elm (for example: groceries ) and I also saw it somewhere on Rosettacode.

express2_dl(Tip,Fin,Str) :-
    Tip =@= Fin  % "structurally equal"
   ,var(Fin)     % and this must also be true
   ,!           
   ,Str="Empty difflist: ∅"
   .

… turns out to be relatively neat as you can easily remove or add lines, check whether commas and dots are there and whether there is a ; lurking in the jungle of the suffixes.

It is just a bit sad that the compiler doesn’t like a comma before the first conjunctive element (which is the cut a conjunctive element btw, it should be in comma position?), that would be even neater:

express2_dl(Tip,Fin,Str) :-
   ,Tip =@= Fin  % "structurally equal"
   ,var(Fin)     % and this must also be true
   ,!           
   ,Str="Empty difflist: ∅"
   .

Just gives

Syntax error: Operator expected

Curses!

(Btw, I thought SWI-Prolog indexes clauses on more than the first argument? I found that adding an integer as first argument makes my program semideterministic. Moved the integer argument to the last position immediately.)

1 Like