Re: Is a PIP for Syntax extensions necessary? (Was; post-N246 Read- and Write-Option variable_names/1)

Anything that touches or depends on syntax
is a complete can of worms. The ISO commitee
was not able to find an initial *english natural
 language specification wording* for character
look-ahead, so that we find now character
look-ahead in Prolog compounds practially
 implemented by all Prolog systems, but character
look-ahead interpretation may differ for
negative numbers, like here:
 /* SWI-Prolog */
?- X = - 1^2, write_canonical(X), nl.
-(^(1,2))
 /* Scryer Prolog */
?- X = - 1^2, write_canonical(X), nl.
^(-1,2)
 But in the case of Scryer Prolog it doesn't
matter, since Scryer Prolog is anyway dead.
 Mild Shock schrieb:

I have a question, does SWI-Prolog not anymore use
their dict syntax in the Janus interface:
>
 > import janus_swi as janus
 > janus.query_once("Y is X+1", {"X":1})
{'Y': 2, 'truth': True}
>
I don’t see _{...} anymore. When and how did this
happen? I was just thinking whether a Syntax
extension PIP is necessary. Such a PIP isn’t listed:
>
https://prolog-lang.org/ImplementersForum/PIPs.html
>
Is SWI-Prolog safe, against parsing problems,
when it still has block operators in the
background? Like can one mix and match
>
code that uses Janus interface with the
“new” dicts with other code that uses the
SWI-Prolog dicts based on _{...}
>
which we might now term the “old” dicts.
How do you access and manipulate the
“new” dicts, do the “old” operations work?