Please don't forbid Math.abs(int/long)

[benjismith]

I just reviewed the pull request #5562 and I strongly disagree with the change.

I'm currently using this feature to implement _delta_ sorting. For example, given these documents:

{ "name" : "John",  "year" : 1975 }
{ "name" : "Jim",  "year" : 1976 }
{ "name" : "James",  "year" : 1977 }
{ "name" : "Jody",  "year" : 1978 }
{ "name" : "Josh",  "year" : 1979 }

Consider a query like this, where I want the 1977 results to come first, and then the 1978 and 1976 results next, and the the 1975 and 1979 results last:

{
  "query" : { "match_all" : {} },
  "sort" : [{
    "_script" : {
      "script" : "abs(1977-doc['year'].value)",
      "order" : "asc"
    }
  }]
}

I use this kind of trick all the time (it's very common in the higher-education domain), and it depends on absolute values for int & long values, so your pull request is going to break my code.

Wouldn't it make more sense to just throw a 400 BAD REQUEST when the query tries to do abs(Integer.MIN_VALUE) instead of removing the function entirely for integral types?

[dakrone]

@benjismith I just tested this locally, forbidding Math.abs(...) in forbiddenapis does not prevent you from using it in scripts, I believe the forbiddenapis check is only during Elasticsearch compilation time.

[benjismith]

Gotcha. My mistake! Thanks for the clarification :)