Re: else ladders practice

On 08.11.2024 23:24, Bart wrote:

On 08/11/2024 17:37, Janis Papanagnou wrote:

>
BTW, the same symbols can also be used as an alternative form
of the 'case' statement; the semantic distinction is made by
context, e.g. the types involved in the construct.

 
You mean whether the 'a' in '(a | b... | c)' has type Bool rather than Int?
 
I've always discriminated on the number of terms between the two |s:
either 1, or more than 1.

I suppose in a [historic] "C" like language it's impossible to
distinguish on type here (given that there was no 'bool' type
[in former times] in "C"). - But I'm not quite sure whether
you're speaking here about your "C"-like language or some other
language you implemented.

 

Bart, out of interest; have you invented that syntax for your
language yourself of borrowed it from another language (like
Algol 68)?

 
It was heavily inspired by the syntax (not the semantics) of Algol68,

(Sure.)

even though I'd never used it at that point.
 
I like that it solved the annoying begin-end aspect of Algol60/Pascal
syntax where you have to write the clunky:
[snip examples]

Well, annoying would be a strong word [for me] here, but yes,
that's what I also find suboptimal. Quite some languages have
adopted the if/fi or if/end forms (and for good reasons, IMO).

 
I enhanced it by not needing stropping (and so not allowing embedded
spaces within names); allowing redundant semicolons while at the same
time, turning newlines into semicolons when a line obviously didn't
continue; plus allowing ordinary 'end' or 'end if' to be used as well as
'fi'.
 
My version then can look like this, a bit less forbidding than Algol68:
 
  if cond then
      s1
      s2
  else
      s3
      s4
  end

(Looks a lot more like a scripting language without semicolons.)

Not sure what you mean by "less forbidding", though. - Algol 68
never appeared to me to restrict me. And it allows more flexible
and coherent application of its concepts (and in a safe way) than
in a lot other common languages.

Janis