But the parser CAN'T look ahead. The parsing rules specify that
a@b@c
is executed as
(a@b)@c
With @: it is true that the operations associate, but the parser doesn't
look for that.
Henry Rich
On 11/10/2022 6:53 PM, bill lam wrote:
I didn't get it.
is parsed as
(}:@:;)@:(,&','&.>)
If parser can look ahead, it should see
}:@:(;@:(,&','&.>))
If it can't then writing it as
(;@:(,&','&.>))
Provides no new information for parser to recognize special code.
On Thu, 10 Nov 2022 at 10:34 PM Henry Rich <[email protected]> wrote:
Thanks Bill. I just want to note a fine point of special code:
}:@:;@:(,&','&.>)
is parsed as
(}:@:;)@:(,&','&.>)
Better is
}:@:(;@:(,&','&.>))
because then the interpreter sees the form
;@:(,&','&.>)
which says 'do something inside the boxes and then immediately join the
contents'.
Armed with the knowledge, the interpreter can leave the contents of the
boxes virtual (something it normally is not allowed to do) until they
are joined.
Henry Rich
On 11/10/2022 7:05 AM, bill lam wrote:
It should be a bug that already fixed in the latest j904 beta. You may
workaround it by replace {: with its equivalent, eg
>(([:,&','each}:),{.@:(_1&{.));:'cat dog mouse'
cat,
dog,
mouse
That said, I would usually do it this way
}:@:;@:(,&','&.>);:'cat dog mouse'
cat,dog,mouse
On Thu, Nov 10, 2022 at 4:42 PM esal <[email protected]> wrote:
Hi everybody
I have an old verb that transforms a boxed array containing database
table
column names into a string suitable for copying and pasting into a SQL
SELECT statement. It crashes J903.
Here is a simplified demonstration.
JVERSION
Engine: j903/j64avx2/windows
Release-b: commercial/2022-01-28T04:09:50
Library: 9.03.08
Qt IDE: 1.9.5s/5.15.2(5.15.2)
Platform: Win 64
Installer: J903 install
InstallPath: c:/j903
Contact: www.jsoftware.com
NB. this works
]aux=.;:'cat dog mouse'
┌───┬───┬─────┐
│cat│dog│mouse│
└───┴───┴─────┘
(([:,&',' each}:),{:)aux
cat,
dog,
mouse
NB. this crashes J
(([:,&',' each}:),{:);:'cat dog mouse'
Best Regards,
Esa
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