What is the '^' in Objective-C -

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what '^' mean in code below?

@implementation appcontroller  - (ibaction) loadcomposition:(id)sender {     void (^handler)(nsinteger);      nsopenpanel *panel = [nsopenpanel openpanel];      [panel setallowedfiletypes:[nsarray arraywithobjects: @"qtz", nil]];      handler = ^(nsinteger result) {         if (result == nsfilehandlingpanelokbutton) {             nsstring *filepath = [[[panel urls] objectatindex:0] path];             if (![qcview loadcompositionfromfile:filepath]) {                 nslog(@"could not load composition");             }         }     };      [panel beginsheetmodalforwindow:qcwindow completionhandler:handler]; } @end

=== i've searched , searched - sort of particular reference memory?

read on here. it's "block object", lambda form, , introduced support snow leopard's gcd (grand central dispatch).


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