Parse C# with a real grammar #122

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1. polewskm

   added

   follow-upWork a plan found and did not doWork a plan found and did not do

   on Oct 31, 2026
2. polewskm commented on Nov 1, 2026

   

   polewskm

   on Nov 1, 2026

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   Measurement for the "if it fails closed too often" condition: declarationSpans from src/csharp.ts was run over every *.cs file outside obj/ and bin/.

   Corpus	Files	Failed closed	Files with #if
   NCodeGroup (18 C# and PowerShell repos, including Identity with 2,834 files)	3,258	0	16, all balanced
   dotnet/runtime sample (CoreLib, System.Text.Json, System.Memory, Common)	3,969	9 (0.23%)	all 9 come from #if branches that each open a brace

   Conditional compilation never makes the api-compat floor fail closed on NCodeGroup code, so a parser dependency isn't justified, and the scanner stays.

   The measurement did find one real bug: a verbatim string whose text starts with an escaped quote (@"""", @"""Hi"" there") was read as a raw string literal, masked to the end of the file, and failed closed. #140 fixes it with a regression test.
3. polewskm

   closed this as completedin #140on Nov 1, 2026