Show(nil) --> Show(true) -- use default
Show(true) --> Show(true) -- arg not nil, use arg
Show(false) --> Show(false) -- arg not nil, use arg
Seconded. It seems like the right semantic in this case is:
function f(x,y=0) --> function f(x,y) y= y==nil and 0 or y;
That's still fairly easy to patch, but, has a behavior that's closer to what a C++ programmer might expect.
Are you planning to allow things other than constants to be used as defaults?
If so, watch out for the potential trouble that can happen near self-referential expressions.
local y={1,2,3}
function f(x=f, y=y[2]) --> naive implementations may segfault here
Peter's old table unpack patch still has a bug in the 'local a in a' case. Which reminds me, I should really get around to posting a fix for that on the wiki...
