Lua list <lua@bazar2.conectiva.com.br> writes:
not using this syntax i hope, because it would make it
impossible to use
tables as keys.
what's wrong with using a explicit call?
function pick (t,...)
end
t = {"apple", "banana", "cherry",
"date"}
pick (t, 2, 4, 3, 4) => { "banana", "date",
"cherry", "date"}
Ahem... yes, you're right - I forgot that the operation
of using a table
as a key was already defined by default.
There's nothing wrong in principle with using a function
to index a table
in this way but it must be possible to pass this
function a table rather
than just a variable length argument list. A table can
be generated at
runtime whereas an argument list is fixed in the source
code.
Another approach to multiple indices might be to define
the function call
operator ( ... ) for tables so that the values passed
are treated as
subscripts. Slices could be modelled using a pair of
integer arguments:-
t = {"apple", "banana", "cherry", "date"}
x = t( 1, 2) -- Gives { "apple", "banana" }
...and when the argument is a table, it could give the
APL-style array
indexing behaviour we have been discussing:-
firstAndLast = { 1, 4 }
x = t( firstAndLast )
...and then of course we would also have:-
x = t{ 1, 4 }
&.
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