Re: Ternary operator patch

2010/9/16 Tom N Harris <telliamed@whoopdedo.org>

But should this have higher or lower precedence than comma? (As mentioned by David M. a few days ago <http://lua-users.org/lists/lua-l/2010-09/msg00360.html>) What does this statement mean?

A,B = if C either D or E,F

I understand that in Lua, comma is not operator. It's a separator for multiple variable/value in an assignment statement, a separator for function arguments, a separator for multiple value in a return statement, and so on. Comma is not an operator, so there is no problem about operator priorities. Comma can separate expressions, but Comma cannot be included in an _expression_. So above line will be:

if C then A,B = D,F else A,B = E,F end

The real question is, if Lua doesn't get a ternary operator, what will be more of a problem? Responding to requests for a ternary operator on the list, or correcting people who type "LUA"?

There are two benefits of a ternary operator, I think.

- For an assignment statement, you have to write left term only once if you can use a ternary operator. This is emphasis when the left term is long and complex.

- The script code and compiled binary is shorter than other notation. So the code will run fast.

And people think "Other major languages have a ternary operator, but why Lua not?"

Thank you

Ryota Hirose