[GR-32340] Predicated configuration for Native Image.

[graalvmbot]

See:
https://github.com/oracle/graal/pull/3606/files#diff-ad2f1f5ee9adf56edcef4ff598e2a3c5ddd3f39e07d428ead926b5446c287f19

[peter-hofer]

The "predicate": declaration is a part of the type object and should be printed by TypeConfiguration. Only the {"whenTypeReachable":"..."} part should be printed here.
Please use the JsonWriter.quote for readability and safety with special characters.

[vjovanov]

So you propose to have redundant checks if the printing of predicated should happen? Then we should duplicate that if and the printing of predicate in all different configuration kinds. This is hardly minimal as ConfigurationPredicate will be uniform in all configuration kinds.

[peter-hofer]

Fair enough, we should simply rename the method to printPredicateAttribute then. Also, I meant ConfigurationType (not TypeConfiguration) in my comment above.

[vjovanov]

Fixed.

[peter-hofer]

The method is still called ConfigurationPredicatePrintable.printJson in your last commit.

[vjovanov]

I am starting to consider changing whenTypeReachable to typeReachable. I think when does not add much to the meaning, but adds to the size of the file. With this change we would have

{
  "predicate" : { "typeReachable" : "io.netty.util.internal.PlatformDependent0" },
  "name" : "sun.misc.Unsafe",
  "fields" : [
    { "name" : "theUnsafe" }
  ]
}

instead of

{
  "predicate" : { "whenTypeReachable" : "io.netty.util.internal.PlatformDependent0" },
  "name" : "sun.misc.Unsafe",
  "fields" : [
    { "name" : "theUnsafe" }
  ]
}

WDYT?

[peter-hofer]

I am starting to consider changing whenTypeReachable to typeReachable. I think when does not add much to the meaning, but adds to the size of the file.

I think this is better regardless of file size concerns. You could consider changing predicate to just if, too -- it comes more natural to programmers anyway. It might be mistaken for an abbreviation though, so perhaps condition is better.

[vjovanov]

Agree, also predicate is something that is evaluated over an argument and yields a boolean. Here the relation to the argument is unclear. So we are left with:

{
  "condition" : { "typeReachable" : "io.netty.util.internal.PlatformDependent0" },
  "name" : "sun.misc.Unsafe",
  "fields" : [
    { "name" : "theUnsafe" }
  ]
}

or

{
  "if" : { "typeReachable" : "io.netty.util.internal.PlatformDependent0" },
  "name" : "sun.misc.Unsafe",
  "fields" : [
    { "name" : "theUnsafe" }
  ]
}

or

{
  "when" : { "typeReachable" : "io.netty.util.internal.PlatformDependent0" },
  "name" : "sun.misc.Unsafe",
  "fields" : [
    { "name" : "theUnsafe" }
  ]
}

[peter-hofer]

Agree, also predicate is something that is evaluated over an argument and yields a boolean. Here the relation to the argument is unclear. So we are left with:

I like condition best, because in my opinion it feels most natural to a reader that the entire entry is conditional on the specified expression, and it is a noun like most other attribute names. With if and when, there is sort of a lingering question of then what?

[vjovanov]

I like condition the most as well. I think it is a safe bet here and fits in the code well. I'll make a PR on top of serialization, and then I'll squash them all with the first commit message refactored.