Re: Latest suggestion for 202x

[Optikos <optikos@verizon.net>]

On Sunday, June 16, 2019 at 3:10:55 PM UTC-5, John Perry wrote:
> On Sunday, June 16, 2019 at 2:34:05 PM UTC-5, Optikos wrote:
> > 2) Algol-family languages (especially the widely-influential Algol60 and the otherwise-influential-on-Ada Algol68) utilize brackets [] for array indexing.  Nearly all other programming languages (which often are little more than Algol60 rejiggered a little bit) have followed Algol's lead on array indexing via bracket [] syntax.
> 
> One exception to this rule is Eiffel, which uses the @ operator. I decided to see if I could find a summary, and [1] has it. The only really strange one IMHO is Haskell, which uses !.
> 
> (This doesn't contradict what you wrote; I just thought it was interesting trivia.)
> 
> [1] https://en.wikipedia.org/wiki/Comparison_of_programming_languages_%28array%29#Indexing

Continuing with the thought of not-() and not-[] oddball languages, let's consider what is going on over in the ML family (of which Haskell is a [distant?] cousin):

Over in the ML family languages, array indexing/subscripting has the following variety of syntaxes—one of which resembles the Fortran–Ada a(i) style:

1) Standard ML invokes a function sub as in sub( a, i ), calling to mind subscripts in mathematics notation.

2) CAML allows the shorthand a.(i), somewhat calling to mind the Fortran–Ada precedent of a(i) and the mathematics function notation (but perhaps the . is to also be a visual nod-of-the-hat to the location of subscripts at or below the baseline typographically).  The shorthand a.(i) is short for the verbose Array.get a i.
https://caml.inria.fr/pub/docs/manual-ocaml/libref/Array.html

3) OCaml reserves [] for lists, so OCaml novelly devised [| |] for calling out elements of an array as in a[|i|].
http://xahlee.info/ocaml/ocaml_list.html

4) Breaking with ATS's otherwise strong influence by SML and OCaml as well as break-in with its homage to mathematics/logic (e.g., renaming what we call types to be sorts as in logic; bringing in a thing called type that has no direct analogy in our programming languages), an ATS sats library defers to Algol's [] convention as in a[i] as shorthand for the verbose array0_get_elt_at( a, i ).

And because I forgot to mention it on a prior posting above (although it has nothing to do with ML family), PL/1 follows Fortran's lead of a(i) syntax, meaning that as far as array syntax goes there is a Fortran–PL/1–Ada continuity in constrast to the Algol a[i] contorted abuse of mathematics' [ ] vector/matrix notation.

C & C++ are the weirdo oddballs on a[i][j] being the syntax for Algol's/Pascal's/ATS's/C#'s a[i,j], Fortran–PL/1–Ada's a(i,j), OCaml's a[|i,j|], and CAML's a.(i,j).