Chip was asking about testing if a set exists or not and put in a feature
request related to this subject. (I voted for it.)
I was just consolidating some old code and ran across something that I
wrote some time back called Set_Exists. No clue. It seems to work, but I
can't say why.
C_BOOLEAN($0;$exists)
C_TEXT($1;$set_name)
$set_name:=$1
Error:=0
ErrorHandler_Install ("ErrorHandler_SuppressError")
C_BOOLEAN($is_in_set)
$is_in_set:=Is in set($set_name)
ErrorHandler_InstallPrevious
$exists:=Error=0 // You could test for error 39 to be a bit more specific.
$0:=$exists
Here's a little routine I wrote to try it out:
ALL RECORDS([Cart])
CREATE SET([Cart];"Cart_All")
REDUCE SELECTION([Cart];0)
UNLOAD RECORD([Cart])
$this_returns_true_correctly:=Set_Exists ("Cart_All")
$this_returns_false_correctly:=Set_Exists ("Foo")
Obviously, you would need to use a table name that exists in your structure
to check this out.
Can anyone confirm/deny that this code is reliable? Seriously, I have no
memory of writing this...Not that unusual for me, frankly...I tend to punch
out reams of code/writing and don't always look back.
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