Open cloudRoutine opened 7 years ago
cloudRoutine
commented
7 years ago As the formatting was completely broken: http://fssnip.net/7OE The line with "// Why?" is triggering an obsolete compiler warning!
cloudRoutine
commented
7 years ago I noticed one more thing: The complete record initializer is triggering the obsolete warning instead of the line accessing the obsoleted field (updated the fssnip version)
cloudRoutine
commented
7 years ago I support the idea shared by Matthias Dittrich.
Hide Obsolete warnings on record initializer not using the obsolete field. [12826233]
Submitted by Matthias Dittrich on 3/6/2016 12:00:00 AM
[ 3 votes ]
Basically the compiler emits a warning even when a obsolete field is not used directly in the source code. Here is a code example showing what I mean: // def version 1 type TestRecordV1 = { Field1 : string Feild2 : string } static member Emtpy = { Field1 = null Feild2 = null } // usage let v1var1 = { TestRecordV1.Emtpy with Field1 = "field1" } let v1var2 = { TestRecordV1.Emtpy with Feild2 = "field2" } let v1var3 = { TestRecordV1.Field1 = "field1"; Feild2 = "field2" } let v1access1 = v1var1.Field1 let v1access2 = v1var1.Feild2 // def version 2 type TestRecordV2 = { Field1 : string [<Obsolete("Use Field2 instead")>] Feild2 : string } static member Emtpy = { Field1 = null Feild2 = null } // can we somehow hide the warning here // (as it is obvious that we need to address it) // usage let v2var1 = { TestRecordV2.Emtpy with Field1 = "field1" } // why? let v2var2 = { TestRecordV2.Emtpy with Feild2 = "field2" } let v2var3 = { TestRecordV2.Field1 = "field1"; Feild2 = "field2" } let v2access1 = v2var1.Field1 let v2access2 = v2var1.Feild2 // def version 3 type TestRecordV3 = { Field1 : string Field2 : string } static member Emtpy = { Field1 = null Field2 = null } // was broken [<Obsolete("Use Field2 instead")>] member x.Feild2 = x.Field2 // usage let v3var1 = { TestRecordV3.Emtpy with Field1 = "field1" } // not broken (yes, old compiled versions are still broken) //let v3var2 = { TestRecordV3.Emtpy with Feild2 = "field2" } // broken let v3var2 = { TestRecordV3.Emtpy with Field2 = "field2" } //let v3var3 = { TestRecordV3.Field1 = "field1"; Feild2 = "field2" } // broken let v3var3 = { TestRecordV3.Field1 = "field1"; Field2 = "field2" } let v3access1 = v3var1.Field1 let v3access2 = v3var1.Feild2 // obsolete, OK I'm pretty sure this is because the code will still break (and use the obsolete field behind the scenes). So even if the suggestion can not be accepted in general (but I think still worth the discussion) we should consider this is in scripting contexts (where binary compatibility is not really a problem). Scripting is the place where I realized this, so currently there really is no good way to use Obsolete on records at all (besides using constructor functions, but then I think the compiler should generate them for me behind the scenes).