Re: Lambda Expressions - filter list without <#list> directive

[D��niel D��k��ny <dd...@apache.org>]

I was thinking about this, and realized that there are two problems with "where" (though maybe "where" is still better than "filter" overall):

1. I bet users will often write products?where(price < 1000), instead of products?where(p -> p.price < 1000). In SQL, the context is implicitly the table row, so you don't have a lambda argument. With ?filter the same mistake is less likely, as your brain doesn't switch to SQL mode.

2. We also have ?map, ?take_while and ?drop_while. These are Java Stream API names. So after seeing these, may will think there must be ?filter as well. (Of course the error message can tell that it's "?where" instead, but it can be still annoying.)

For now I left it as ?filter, but it's still not too late to change it. Someone else has opinion?

On 2019/07/02 20:18:30, Denis Bredelet <br...@mac.com.INVALID> wrote: 
> 
> > Le 2 juil. 2019 à 20:29, Pete Helgren <pe...@valadd.com> a écrit :
> > 
> > As a more casual Java programmer, the "where" option is much clearer to me. I spend more time using FM syntax than changing the Java underneath, so from a "fading memory" standpoint, "where" would lead to fewer "What the....?" moments,  for me at least.
> 
> I prefer « where » for the reasons Daniel mentioned, also SQL uses WHERE.
> 
> I think SQL has as many users as Javascript, no?
> 
> — Denis.
> 
> > 
> > Pete Helgren
> > www.petesworkshop.com
> > GIAC Secure Software Programmer-Java
> > Twitter - Sys_i_Geek  IBM_i_Geek
> > 
> > On 7/2/2019 2:08 PM, Christoph Rüger wrote:
> >> Good point. Seems you are not the first ones stumbling on that one.
> >> I quickly searched around and found:
> >> 
> >> Similar question on SO:
> >> https://stackoverflow.com/questions/45939202/filter-naming-convention
> >> Javascript: filter :
> >> https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Global_Objects/Array/filter
> >> Spark SQL -> "where" is an alias for "filter":
> >> https://stackoverflow.com/a/33887122/135535
> >> <https://stackoverflow.com/questions/33885979/difference-between-filter-and-where-in-scala-spark-sql>
> >> -> search for "filter" or "where" on
> >> https://spark.apache.org/docs/1.5.2/api/scala/index.html#org.apache.spark.sql.DataFrame
> >> R Statistics Language : filter
> >> https://cran.r-project.org/web/packages/dplyr/vignettes/dplyr.html#filter-rows-with-filter
> >> 
> >> Python: filter https://www.geeksforgeeks.org/filter-in-python/
> >> Ruby: they use select:
> >> https://www.codementor.io/tips/8247613177/how-to-filter-arrays-of-data-in-ruby
> >> Kotlin: filter:
> >> https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/filter.html
> >> 
> >> This languages rank in the upper area of the Stackoverflow survey:
> >> https://insights.stackoverflow.com/survey/2019#technology-_-programming-scripting-and-markup-languages
> >> 
> >> I agree that "where" reads pretty nice. I like it. But "filter" seems to be
> >> found in multiple common languages supporting lambdaish syntax.
> >> Python and R is especially common in the data science / statistics
> >> community, which are different target group than e.g. Java-Programmers.
> >> Also web-developers these days are doing lots of javascript to build "html"
> >> websites / templates - and javascript also uses "filter".
> >> 
> >> My vote would still go for "filter", because I think we are working on
> >> lists of objects and objects are closer to "programming" than to "sql".
> >> Maybe the "where"-alias would be a compromise - but might also be confusing
> >> two have both.
> >> 
> >> What do others think?
> >> 
> >> Thanks
> >> Christoph
> >> 
> >> 
> >> 
> >> 
> >> 
> >> 
> >> 
> >> Am Di., 2. Juli 2019 um 20:27 Uhr schrieb Daniel Dekany <ddekany@apache.org
> >>> :
> >>> I wonder if "filter" is a good name. For Java 8 programmers it's
> >>> given, but otherwise I find it confusing, as it's not clear if you
> >>> specify what to filter out, or what to keep. Worse, I believe in every
> >>> day English "foo filter" or "filters foo" means removing foo-s because
> >>> you don't want them, which is just the opposite of the meaning in
> >>> Java. So I think "where", which is familiar for many from SQL (for
> >>> most Java programmers as well, but also for non-Java programmers),
> >>> would be better. Consider:
> >>> 
> >>>   users?filter(user -> user.inactive)
> >>> 
> >>> VS
> >>> 
> >>>   users?where(user -> user.inactive)
> >>> 
> >>> The first can be easily misunderstood as removing the inactive users,
> >>> while the meaning of the second is obvious.
> >>> 
> 
>