Kevin, I believe you don't need any of the (){} characters there, but maybe
I'm missing something.
On Jul 27, 2012 6:04 AM, "Kevin Wright" <[email protected]> wrote:
> That's a bit open-ended, are you thinking of a particular construct that
> you think would be challenging to convert?
>
> As another trivial example, something like this:
>
> final A a = getA();
> if (a != null) {
> final B b = getBFrom(a);
> if (b != null) {
> doSomethingWithB(b);
> } else {
> doSomethingIfBWasAbsent();
> }
> } else {
> doSomethingIfAWasAbsent();
> }
>
>
> Or with the tertiary operator:
>
> final A a = getA();
> (a == null) ? doSomethingIfAWasAbsent() : {
> final B b = getBFrom(a);
> (b == null) ? doSomethingIfBWasAbsent() : {
> doSomethingWithB(b);
> }
> };
>
>
> Could be written in Scala as:
>
> val a = getA
> val b = a flatMap {getBFrom}
> a getOrElse {doSomethingIfAWasAbsent()}
> b getOrElse {doSomethingIfBWasAbsent()}
> b forEach {doSomethingWithB}
>
>
>
>
>
> On 27 July 2012 04:16, Cédric Beust ♔ <[email protected]> wrote:
>
>> Yes but that's the most trivial case. For example, experiment with your
>> Option code when the original code has else's.
>>
>> --
>> Cédric
>>
>>
>>
>>
>> On Thu, Jul 26, 2012 at 5:30 PM, clay <[email protected]> wrote:
>>
>>> Here is a simple example that illustrates the benefit of Option beyond
>>> avoiding null exceptions:
>>>
>>> Here is a traditional piece of logic using traditional null if-checks.
>>> This is using Scala syntax but would be equivalent in Java.
>>>
>>> val variableAMayBeNull: A = methodThatMayProduceA();
>>> if (variableAMayBeNull != null) {
>>> val variableBMayBeNull: B = tryToGetBFromA(variableAMayBeNull);
>>>
>>> if (variableBMayBeNull != null) {
>>> doSomethingWithNonNullB(variableBMayBeNull);
>>> }
>>> }
>>>
>>> Same logic using Option. This is Scala syntax. Java can do this but not
>>> as nicely until it gets lambdas.
>>>
>>> val variableAMayBeNull: Option[A] = methodThatMayProduceA();
>>> val variableBMayBeNull: Option[B] =
>>> variableAMayBeNull.flatMap(tryToGetBFromA);
>>> variableBMayBeNull.foreach(doSomethingWithNonNullB);
>>>
>>> Both blocks are logically equivalent, but the Option route is much more
>>> concise, elegant, and maintainable. The if-logic is moved from the end
>>> application code to inside of the Option class. Since this type of logic is
>>> so common in application code, the code simplification benefits are quite
>>> large.
>>>
>>>
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