Is telling the user that the Closure cannot be empty the only
application for this ? If yes, given that a user can easily pass a
non-empty but non-meaningful closure anyway I would question whether it
is worth the effort.
Cheers,
mg
PS: Also wondering whether we could achieve the same thing through the
Closure return type, e.g.:
@Test @Ignore void closureFooTest() {
println closureFoo {}
println closureFoo{ "abc" } }
def closureFoo(Closure<String> cls) {
return "the string is: ${cls()}" }
Should imho fail to compile, since an empty Closure should have return
type void.
Currently it does compile and run though (under 2.5.x) , even with
@CompileStatic, since the empty closure implicitely returns null (imho
one of the few bad design decisions in Groovy (whether in closures or
somewhere else)), but at least IntelliJ marks it as invalid...
On 17/02/2021 19:51, Daniel Sun wrote:
Groovy does not support checking empty closure at runtime AFAIK, but we could
check and set some property to closure while compiling, then get the property
at runtime. It will be an new improvement, not sure if others like it or not.
Cheers,
Daniel Sun
On 2021/02/17 15:06:47, OCsite <[email protected]> wrote:
Hi there,
is it possible to reliably recognise an empty closure, i.e., „{}“,
programmatically?
def foo(Closure bar) {
if (?bar-is-empty?) throw new Exception('The closure cannot be empty!')
else bar()
}
foo { println "ok" } // OK
foo { 1 } // OK
foo { } // throws
Thanks!
OC
