This approach requires a restriction: [no LineTerminator here] between
the ) and the {:
js> function f(a,b,c){return a*b+c}
js> var x=2,y=3,z=4,w
js> f(x,y,z) {
typein:3: SyntaxError: missing ; before statement:
typein:3: f(x,y,z) {
typein:3: .........^
js> eval("w=f(x,y,z)\n{print(w)}")
10
(That last "10" came from print(w) of course; the completion value of
the eval was undefined.)
Leaving out the f in the "definition" doesn't help, since (a,b,c) is a
comma expression. The requirement is no LineTerminator between the ) and
the {.
We went around a nearby block recently, in considering {(a,b)...} for
block lambdas. Everyone I remember initially favoring this syntax came
around to oppose it because the opportunity for confusion due to
parenthesized expression statements already mixing with curly-braced
block statements was too great.
Perhaps this case is different enough. But is it? Modified Prototype 1.6:
inGroupsOf(number, fillWith) {
fillWith = Object.isUndefined(fillWith) ? null : fillWith;
return this.eachSlice(number, (slice) {
while(slice.length < number) slice.push(fillWith);
return slice;
});
},
inject(memo, iterator, context) {
iterator = iterator.bind(context);
this.each((value, index) {
memo = iterator(memo, value, index);
});
return memo;
},
invoke(method) {
var args = $A(arguments).slice(1);
return this.map((value) {
return value[method].apply(value, args);
});
},
I've obviously also used method definition shorthand by changing any ":
function (" occurrences in the original prototype code to just "(".
Without a leading keyword, it's harder to find the functions. Not
impossible, not saying this is a deal breaker. But it is harder.
/be
Isaac Schlueter wrote:
On Tue, Mar 6, 2012 at 10:07, Thaddee Tyl <[email protected]
<mailto:[email protected]>> wrote:
An interesting property of this syntax is that anonymous functions can
be written this way:
myList.forEach(λ (item) { doWith(item) })
(it can also be `lambda (item) { ... }`)
Yes, any valid function identifier could be used, because it's not
actually a keyword.
_ (arg) { ... }
f (arg) { ... }
$ (arg) { ... }
ƒ (arg) { ... }
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