new text syntax

[Geal]

I'm simplifying the text syntax, but it can still be a bit confusing, so I'd lie to propose a different version, that's further from traditional datalog syntax.
I'd like to change from:

right(#authority, $1, #read) <- resource(#ambient, $1), owner(#ambient, $0, $1)

to

right(#authority, $1, #read) if resource(#ambient, $1) and owner(#ambient, $0, $1)

with if and and case insensitive, so we can write right(#authority, $1, #read) IF resource(#ambient, $1) AND owner(#ambient, $0, $1) if it's easier to read without text highlighting

And for caveats:

caveat1($0, $1) <- right(#authority, $0, $1), resource(#ambient, $0), operation(#ambient, $1)

to

check right(#authority, $0, $1) and resource(#ambient, $0) and operation(#ambient, $1)

or another keyword, like verify, satisfy, ensures, assert, etc

For constraints, instead of moving them to the end like this:

valid_date("file1") <- time(#ambient, $0 ), resource(#ambient, "file1") @ $0 <= 2019-12-04T09:46:41+00:00

we would write:

valid_date("file1") if time(#ambient, $0 ) and resource(#ambient, "file1") and $0 <= 2019-12-04T09:46:41+00:00

And constraints could be anywhere in the rule's body, like this:

valid_date("file1") if time(#ambient, $0 ) and $0 <= 2019-12-04T09:46:41+00:00 and resource(#ambient, "file1")

[daeMOn63]

on my side I think I still prefer the current version, I find it easier to read those symbols than text for some reasons.
But this is quite subjective. If we're still moving to this, I'd suggest we keep the current constraint placement, and maybe just replace the '@' with the 'with' keyword:

valid_date("file1") if time(#ambient, $time ) and resource(#ambient, "file1") with $time <= 2019-12-04T09:46:41+00:00

mainly to ease auto formatting, I found out the following structure works quite well as it can be aligned nicely:

valid_date("file1") 
    <- time(#ambient, $time ),
       resource(#ambient, "file1") 
    @  $time <= 2019-12-04T09:46:41+00:00

keywords in place of symbols already mess it up a bit:

valid_date("file1") 
    if time(#ambient, $time )
    and resource(#ambient, "file1") 
    with $time <= 2019-12-04T09:46:41+00:00

wdyt ?

[meh]

I also prefer the current syntax.

[Geal]

v2 now has a new syntax with a defined grammar #72