Shallow copy all but one entry from groovy map

Question

I need to shallow copy all entries in a Groovy map except for one, for which I already know the key. I prefer immutable and succinct approaches, and the minus() method is a pretty good fit except that providing the key isn't sufficient, and I would have to do something like this:

def map = [a:"aa", b:"bb"]

def knownKey = "a"
def result = map - [(knownKey):map[knownKey]]
assert result == [b:"bb"]

Alternatively I could give up (temporarily) on immutability and call the remove() method with the key as argument.

Is there a groovy'er approach I could take?

Answer 1

You should use findAll as below:

def map = [a:"aa", b:"bb"]
def knownKey = "a"
def result = map.findAll { it.key != knownKey }
assert result == [b:"bb"]