notes/pl/groovy/features/closure.txt

2019
https://www.baeldung.com/groovy-closures


c.resolveStrategy = CLOSURE.OWNER_FIRST
// DELEGATE_FIRST, DELEGATE_ONLY, OWNER_ONLY

the groovy for-in loop

for (n in nums) {
    println n
}

nums.each { println it }
nums.each { n -> println n }
nums.eachWithIndex { n, idx -> println "nums[$idx] == $n" }


Map m = [a:1, b:2, c:2]

def result = ''
def result = ''
[a:1, b:3].each { key, val -> result += "$key$val" }
assert result == 'a1b3'

def result = ''
[a:1, b:3].each { entry -> result += entry }
assert result == 'a=1b=3'

If you have a method with the last argument is a closure,
then the typical groovy idiom is to put closure after the parenthesis

Number class:
void downto(Number to, Closure closure)

10.downto(7, { println it })
10.downto(7) { println it } // the most idiomatic groovy
10.downto 7, { println it }

// in java 8 lambda - we can only access final vars inside a lambda
// in groovy - delegation (if symbol can't be resolved within a closure scope)
// controlled by Closure.delegate property