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https://issues.apache.org/jira/browse/GROOVY-8870?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Eric Milles updated GROOVY-8870:
--------------------------------
Description:
I'm not sure if this is intended, but I ran into some nice/useful behavior of
the spread-dot operator when applying to a list of lists. I was trying to use
{{collectMany}} and found that I would need to do an inner {{collectMany}} or
switch to {{inject}}. But it turns out spread-dot and {{flatten}} handled the
situation very nicely.
Could you please add a note on this to the documentation (section 1.2.8 --
other operators)? I don't think it is common knowledge that spread-dot does
not always gather up results in a flat list.
{code:groovy}
class Foo {
String thing
}
class Bar {
List<Foo> foos
}
class Baz {
List<Bar> bars
}
List<Foo> f = [new Foo(thing:'1'), new Foo(thing:'2')]
assert f*.thing == ['1','2']
List<Bar> b = [new Bar(foos:f), new Bar(foos:f)]
assert b*.foos*.thing == [['1','2'], ['1','2']]
assert b*.foos*.thing.flatten() == ['1','2','1','2']
// this was my use case:
List<Baz> z = [new Baz(bars:b), new Baz(bars:b)]
assert z*.bars*.foos == [[f, f], [f, f]] // each f is a list of 2 Foos
assert z*.bars*.foos*.thing == [[['1','2'], ['1','2']], [['1','2'], ['1','2']]]
assert z*.bars*.foos*.thing.flatten() == ['1','2','1','2','1','2','1','2'] //
for the win!
// in this case I could have also written it without the stars:
assert z.bars.foos.thing.flatten() == ['1','2','1','2','1','2','1','2']
{code}
was:
I'm not sure if this is intended, but I ran into some nice/useful behavior of
the spread-dot operator when applying to a list of lists. I was trying to use
{{collectMany}} and found that I would need to do an inner {{collectMany}} or
switch to {{inject}}. But it turns out spread-dot and {{flatten}} handled the
situation very nicely.
Could you please add a note on this to the documentation (section 1.2.8 --
other operators)? I don't think it is common knowledge that spread-dot does
not always gather up results in a flat list.
{code:groovy}
class Foo {
String thing
}
class Bar {
List<Foo> foos
}
class Baz {
List<Bar> bars
}
List<Foo> f = [new Foo(thing:'1'), new Foo(thing:'2')]
assert f*.thing == ['1','2']
List<Bar> b = [new Bar(foos:f), new Bar(foos:f)]
assert b*.foos*.thing == [['1','2'], ['1','2']]
assert b*.foos*.thing.flatten() == ['1','2','1','2']
// this was my use case:
List<Baz> z = [new Baz(bars:b), new Baz(bars:b)]
assert z*.bars*.foos == [[f, f], [f, f]] // each f is a list of 2 Foos
assert z*.bars*.foos*.thing == [[['1','2'], ['1','2']], [['1','2'], ['1','2']]]
assert z*.bars*.foos*.thing.flatten() == ['1','2','1','2','1','2','1','2'] //
for the win!
{code}
> Spread-dot operator on list of lists
> ------------------------------------
>
> Key: GROOVY-8870
> URL: https://issues.apache.org/jira/browse/GROOVY-8870
> Project: Groovy
> Issue Type: Documentation
> Reporter: Eric Milles
> Priority: Minor
>
> I'm not sure if this is intended, but I ran into some nice/useful behavior of
> the spread-dot operator when applying to a list of lists. I was trying to
> use {{collectMany}} and found that I would need to do an inner
> {{collectMany}} or switch to {{inject}}. But it turns out spread-dot and
> {{flatten}} handled the situation very nicely.
> Could you please add a note on this to the documentation (section 1.2.8 --
> other operators)? I don't think it is common knowledge that spread-dot does
> not always gather up results in a flat list.
> {code:groovy}
> class Foo {
> String thing
> }
> class Bar {
> List<Foo> foos
> }
> class Baz {
> List<Bar> bars
> }
> List<Foo> f = [new Foo(thing:'1'), new Foo(thing:'2')]
> assert f*.thing == ['1','2']
> List<Bar> b = [new Bar(foos:f), new Bar(foos:f)]
> assert b*.foos*.thing == [['1','2'], ['1','2']]
> assert b*.foos*.thing.flatten() == ['1','2','1','2']
> // this was my use case:
> List<Baz> z = [new Baz(bars:b), new Baz(bars:b)]
> assert z*.bars*.foos == [[f, f], [f, f]] // each f is a list of 2 Foos
> assert z*.bars*.foos*.thing == [[['1','2'], ['1','2']], [['1','2'],
> ['1','2']]]
> assert z*.bars*.foos*.thing.flatten() == ['1','2','1','2','1','2','1','2']
> // for the win!
> // in this case I could have also written it without the stars:
> assert z.bars.foos.thing.flatten() == ['1','2','1','2','1','2','1','2']
> {code}
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