>
> To put things in perspective, => was introduced in version 3.1, together with
> map and array support. As far as I understand it and looking again at the
> specs, one of the use cases is for => to be used with maps and arrays, in an
> object-oriented style.
In particular, arrays don't have a filter operator in the way that sequences
do, neither do they have a mapping operator, so to select into an array of maps
you need to do things like
$A => a:filter( function($m) {$m?name='Mike'}) => a:for-each( function($m) {
$m?age })
which gets terribly unwieldy if you try to write it with conventional nested
function calls.
I wish we had done a concise anonymous function declaration as well:
$A => a:filter( {?name='Mike'} ) => a:for-each( {?age} )
Here {EXPR} is shorthand for "function($x){ $x ! EXPR }"
but that would have been a bridge too far for some people.
Michael Kay
Saxonica
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