// control.groovy — if, switch, loops and "Groovy truth".

// Groovy truth: these all count as false in a condition
def falsy = [null, 0, '', [], [:], false]
falsy.each { value -> assert !value }
println 'null, 0, empty string, empty list, empty map and false are all "false"'

def customer = ''
if (!customer) {
    println 'No customer given'          // runs: empty string is false
}

// Elvis operator: value if it's "true", otherwise a default
def name = customer ?: 'Guest'
println name                             // Guest

// switch is very flexible in Groovy
def describe(value) {
    switch (value) {
        case null          -> 'nothing'
        case Integer       -> "a number: $value"
        case ~/[A-Z]{2}-\d{3}/ -> "a SKU: $value"
        case ['NEW', 'OPEN'] -> 'an open status'
        case { it instanceof List && it.size() > 2 } -> 'a long list'
        default            -> "something else: $value"
    }
}
['AX-200', 42, 'NEW', [1, 2, 3], null, 'hello'].each { println describe(it) }

// Loops
for (sku in ['AX-200', 'BX-310']) println "for-in: $sku"
3.times { i -> println "times: $i" }
1.upto(3) { println "upto: $it" }
def n = 0
while (n < 2) { println "while: ${n++}" }