>a benefit, as there is literally not a single place in Lua where an
>assignment _expression_ would save more than a single line of code.
One place where Lua has similar syntax to Pyhon is if-elseif statements. Assignment expressions let you avoid extra nesting here.
if x := foo:match(p1) then
-- A
elseif x := foo:match(p2) then
-- B
elseif x := foo:match(p3) then
-- C
end
-- vs
local x = foo:match(p1)
if x then
-- A
else
x = foo:match(p2)
if x then
-- B
else
x = foo:match(p3)
if x then
-- C
end
end
end
end
That's a valid point. I hadn't considered that specific example, although I would write it differently anyway:
local x = foo:match(p1)
if x then
-- A
return
end
x = foo:match(p2)
if x then
-- B
return
end
x = foo:match(p3)
if x then
-- C
return
end
(Replace "return" with whatever other control structure is appropriate for the context, of course. break is another good choice.)
I suppose by a strict interpretation this saves two lines per assignment _expression_ instead of just the one that I had asserted, but there's a fairly good chance that the return statement would have been there anyway, if it returned a value.
Though it should be noted that in your example you still need a "local x" at the top to preserve the same semantics.
/s/ Adam
