davidson wrote: > On Sat, 8 Apr 2023 Emanuel Berg wrote: > >> Tom Dial wrote: >> >>>>> Look at the use of parentheses in Lisp [...] >>>> >>>> I have thought about that - is Lisp possible without them? >>>> But how do you then know priority? I'm sure someone tried >>>> to get rid of them, but how? >>> >>> Its quite a few years since I had anything to do with Lisp, >>> and even more since I wrote my Symbolic Logic final using >>> parenthesis-free Polish notation (i.e., Reversed RPN). >> >> Yes, you mean instead of >> >> (* 1 2 (+ 1 2 3) 3) >> >> How would that look? > > That particular term, with those commutative operators (in > *Reversed* Reverse Polish Notation, ie, in Polish/Prefix > Notation), is equivalent to this: > > * 1 2 3 + 1 2 3
? Not following ... > In the general case, allowing operators of variable arity > (which I doubt were part of the logic exam) require an > arity-indicating argument, but that's simple enough, > isn't it? > > So your example, without commutation of the arguments, would be > > *4 1 2 +3 1 2 3 3 > > with *4 indicating 4-nary multiplication, and +3 > ternary addition. No can't have that, what if you don't know the arity (it's computed) and no new goofy syntax introduced haha :) -- underground experts united https://dataswamp.org/~incal