Exploring a exists operator for Kaffeine

gistfile1.txt

/* do we want 
a?.b  => a && a.b          // minimal code created

a?.b  => a != null && a.b   // we get not null comparison - perhaps a sweet spot 

a?.b  => (typeof a != "undefined" && a != null) && a.b   // CS style - makes messy looking JS? 

--- ?? operator
a??   => (typeof a != "undefined")  // interesting - probably not useful ? 
*/

compiles: 

a?

to:

a != null

compiles:

a?.b

to:

(a != null) && a.b

compiles: 

a()?.b

var _x; _x = a(); _x != null && _x.b

CS is doing it correctly (a != null). The ? operator is mainly existing to prohibit errors that only occur when you try to access properties of null or undefined. Every other expression is a kind of object.
false.toString()
should be allowed.

Yes that makes sense. The point is I am proposing to not check for undefined variables. Seems like an edge case.

…

On 17 Apr 2011, at 14:58, akidee ***@***.*** wrote: CS is doing it correctly (`a != null`). The ? operator is mainly existing to prohibit errors that only occur when you try to access properties of null or undefined. Every other expression is a kind of object. false.toString() should be allowed. ## Reply to this email directly or view it on GitHub: https://gist.github.com/923899