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> because compiler enforces its proper usage For languages where the compiler doesn’t help, is there any benefit? I’ve seen Option in Java projects where it ju

> because compiler enforces its proper usage For languages where the compiler doesn’t help, is there any benefit? I’ve seen Option in Java projects where it just seems to add one more layer of could-be-null.

bheadmaster 3y ago
There's always benefit, as long as programmers stick to it. Compilers and linters help a lot, but it's not impossible to do without them, just requires more discipline and effort. And you don't have that "it compiles" guarantee that makes you feel warm and fuzzy inside.
marginalia_nu 3y ago
Java's optionals are incredibly half-baked IMO, and I say this as someone who is generally quite pro-Java. They make the code slower, harder to read and don't really solve any problem.
- valenterry 3y ago
  Yeah, in particular since you cannot have Some(null) which is just very bad design because it makes interaction with code that uses null impossible (or unreliable). And syntactically, it's not a pleasure to use, but that's more a fault of Java being so verbose and limited in terms of the typesystem, not a fault of the Optional type.
  - marginalia_nu 3y ago
    I don't think amending the type system (or using the existing type system) would make sense for Java. I think either a null-delegating operator (like C#'s foo.?bar ); or a variable modifier (a bit like 'final') that doesn't permit nulls would make far more sense in the context of the language at large. In fact, the approach is commonly enforced through annotations and static analysis. Built-in support for the construct would be very beneficial.
    - valenterry 3y ago
      Yeah, I agree.
brabel 3y ago
The rule in Java, enforced by the programmer, not the compiler, is that you never assign an Optional to null. If a method returns Optional, you're free to assume it will never return null. If it does, you should track down and publicly shame the author of such monstrosity.
- mst 3y ago
  "If you do that, ideally, a small gnome climbs out the back of the computer and hits the developer with a mallet." (various bits of perl IRC have adopted the mallet gnome as an idiom over the years and it seems to convey the "please don't" point without being overly combative ;)
CodesInChaos 3y ago
One important property of options is that they don't get flattened when nested. None and Some(None) are different.

bheadmaster 3y ago

There's always benefit, as long as programmers stick to it. Compilers and linters help a lot, but it's not impossible to do without them, just requires more discipline and effort. And you don't have that "it compiles" guarantee that makes you feel warm and fuzzy inside.

marginalia_nu 3y ago

Java's optionals are incredibly half-baked IMO, and I say this as someone who is generally quite pro-Java. They make the code slower, harder to read and don't really solve any problem.

valenterry 3y ago
Yeah, in particular since you cannot have Some(null) which is just very bad design because it makes interaction with code that uses null impossible (or unreliable). And syntactically, it's not a pleasure to use, but that's more a fault of Java being so verbose and limited in terms of the typesystem, not a fault of the Optional type.
- marginalia_nu 3y ago
  I don't think amending the type system (or using the existing type system) would make sense for Java. I think either a null-delegating operator (like C#'s foo.?bar ); or a variable modifier (a bit like 'final') that doesn't permit nulls would make far more sense in the context of the language at large. In fact, the approach is commonly enforced through annotations and static analysis. Built-in support for the construct would be very beneficial.
  - valenterry 3y ago
    Yeah, I agree.

brabel 3y ago

The rule in Java, enforced by the programmer, not the compiler, is that you never assign an Optional to null. If a method returns Optional, you're free to assume it will never return null. If it does, you should track down and publicly shame the author of such monstrosity.

mst 3y ago
"If you do that, ideally, a small gnome climbs out the back of the computer and hits the developer with a mallet." (various bits of perl IRC have adopted the mallet gnome as an idiom over the years and it seems to convey the "please don't" point without being overly combative ;)

CodesInChaos 3y ago

One important property of options is that they don't get flattened when nested. None and Some(None) are different.