Java didn't use the term "keyword" but chose "reserved type" since generally you can't use keywords in most other places in your code, but for backwards compatibility you can still have "var" as a variable name. Groovy also lets you have var as a variable name as well as lets you have keywords in certain places:
var var = [def: 1, as: 2, in: 3, trait: 4] You are certainly within your rights to not like "var" and think of it as a cross language copy-n-paste hack, but Groovy generally tries to stay agnostic on such matters. Groovy users are smart enough to be able to decide whether they want OO/functional, static/dynamic typing, var/def, closures/lambdas, etc. We want Java developers to be able to come to Groovy and bring their preferred styles with them. Of course, you can write a codenarc rule that flags "var" usage with warnings if you particularly don't want "var" style in your codebases. Cheers, Paul. On Wed, Nov 27, 2024 at 8:35 PM Gianluca Sartori <g.sart...@gmail.com> wrote: > > >> 'var' support [..] slightly more flexible >> than Java but definitely not use var (short for variable) for methods. > > > You say it is "short for variable" (like in "define a variable?") but the > documentation says it is "short for Object". It says it is a "Type > Placeholder". > > This is confusing because neither Java nor Groovy have a specific keyword to > define variables. > > In both languages variables are defined by preposing a Type before the > variable name. > In both languages methods are defined by preposing a Type before the method > name. > > So if `var` is to be a Type Placeholder it should be valid in all contexts > where a Type is valid, so everywhere `def` is valid. > > Now, I understand it may not be immediate to use `var` in front of a method > definition but if it is documented as a Type Placeholder then that's the way > our mind will look at it. > > I never saw `def` as something else than a keyword in Python, because in the > docs they say it is a keyword. > I never saw `def` as a keyboard in Groovy because in the docs they say it is > a type placeholder equivalent to Object. > > I think it is a mistake for Groovy to document `var` the way it is documented > today. Because it is suggesting people to use it, but it is not a core Groovy > feature, it is not idiomatic Groovy, it is a marginal addition that exists > just to make a compiler happy when copy-pasting Java code. It should not be > mentioned in the docs along with `def`. It should be documented in a separate > chapter "Java source code compatibility"or something like that. > > Cheers, > Gianluca > > >> >> Cheers, Paul. >> >> On Wed, Nov 27, 2024 at 4:46 AM Gianluca Sartori <g.sart...@gmail.com> wrote: >> > >> > >> > >> >> For me, def == var, in my mental model. Which means == Object. >> > >> > >> > This is how I was looking at it since that’s how it has been documented, >> > but it has not been implemented that way. >> > >> > At this point of the discussion I understood it is a documentation issue, >> > but still something in my mind is telling me we should have def == var. >> > >> > It would be groovier! >> > >> > Cheers, >> > Gianluca >> > >> > >> > >> >> On Tue, Nov 26, 2024 at 5:08 PM MG <mg...@arscreat.com> wrote: >> >>> >> >>> Hi Rémi, >> >>> >> >>> yes, I saw that, thank you. >> >>> >> >>> Most of the examples seemed obvious to me, and the bugs that could be >> >>> introduced feel like they are a little bit on the artficial side. >> >>> >> >>> But, having said that: Inferring an interface type or a less specific >> >>> parent type in some cases could imho be a very Groovy thing: >> >>> >> >>> e.g. inferring List<T> instead of ArrayList<T> >> >>> Potentially through some explicit construct, such as "var>" to indicate >> >>> that a more loose / interface type shall be used. >> >>> >> >>> Not that I see any of that becoming a reality anywhere in the near >> >>> future... ;-) >> >>> >> >>> Cheers, mg >> >>> >> >>> PS: I googled a bit, and I could not find in general that ppl think var >> >>> in Java is something you should avoid. Instead, as with any language >> >>> feature, one can over-/abuse it, thereby making code less readable than >> >>> when using explicit types. >> >>> It is funny thinking about this in the context of Groovy, where >> >>> typically ppl who use it as a scripting language do not even use final >> >>> instead of def when defining variables, even though they will never >> >>> reassign said variable 99% of the time... ;-) >> >>> >> >>> There is an official guide that explains some of the gotchas >> >>> https://openjdk.org/projects/amber/guides/lvti-style-guide >> >>> >> >>> regards, >> >>> Rémi >> >>> >> >> >> >> >> >> -- >> >> Guillaume Laforge >> >> Apache Groovy committer >> >> Developer Advocate @ Google Cloud >> >> >> >> Blog: glaforge.dev >> >> Twitter: @glaforge >> >> Mastodon: @glafo...@uwyn.net
