On Aug 01, 2007, at 13:30, Roberto Ierusalimschy wrote:
Another option is to implement tuples. We can implement them as C
functions with upvalues (PiL2, p. 257). With a few extra lines of code,
we get the following:
a = new.tuple(2, nil, "foo")
#a -- not available; perhaps a"#" ???
a:insert("baz") -- not available (tuples are immutable)
a(3) -- yields "foo"
a() -- yields 2, nil, "foo"
for i, v in a do ... -- or something like this...
Here is a straight Lua implementation of sort: local Tuple = require( 'Tuple' ) local aTuple = Tuple( 2, nil, 'foo', nil ) print( #aTuple ) print( aTuple( 3 ) ) for anIndex, aValue in aTuple do print( anIndex, aValue ) end > 4 > foo > 1 2 > 2 nil > 3 foo > 4 nil
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