Come on.. Anonymous functions (lambdas) have the simple rule - use them when you need a function as an argument to a high-order function (such as filter or map)

Come on.. Anonymous functions (lambdas) have the simple rule - use them when you need a function as an argument to a high-order function (such as filter or map) right here, in this call, because giving it a name and, especially place where you can't see its code, is less concise. If a function, it turns out, should be called more than once, it deserves a name. The practice of placing any general functionality in lambdas or blocks will make thing more messy.