Replace switch-case/if-else block with maps

switchMaps.groovy

def sum(a, b) {
    println "sum"
    a + b
}

def sub(a, b) {
    println "sub"
    a - b
}

def d = [
    'sum': this.&sum,
    'sub': this.&sub
]

println d['sum'](10, 10)