Search for Related Error Codes

Search for theme-related diagnostics that may have been missed during initial consolidation. Preserve all three phase boundaries and approval gates.

Required Inputs

Collect these inputs from the user:

• Destination filename: The consolidated .md file in docs/csharp/language-reference/compiler-messages/.
• Theme description: The theme to search for.

Key Paths

• Destination: docs/csharp/language-reference/compiler-messages/{destination-filename}
• TOC: docs/csharp/language-reference/toc.yml
• Catch-all: docs/csharp/misc/sorry-we-don-t-have-specifics-on-this-csharp-error.md
• Roslyn error codes: ../roslyn/src/Compilers/CSharp/Portable/Errors/ErrorCode.cs
• Roslyn resources: ../roslyn/src/Compilers/CSharp/Portable/CSharpResources.resx

Phase A: Search Existing Documentation

1. Read the destination and collect all included error codes.
2. Search all files whose names begin with cs in:
   • docs/csharp/language-reference/compiler-messages/
   • docs/csharp/misc/
3. Read every candidate and decide whether its diagnostic relates to the theme.
4. Build a candidate list containing the file, error code, and a brief reason it matches.

Present the list and stop:

| File | Error Code | Reason |
|------|------------|--------|
| cs0220.md | CS0220 | Describes compile-time overflow |

Tell the user:

Review this list. Approve the files you want merged, then run the error-consolidation-merge-existing skill with the approved list.

Wait for the user before proceeding to Phase B. Do not merge candidates in this skill.

Phase B: Search Undocumented Catch-All Errors

After the Phase A gate is satisfied:

1. Read f1_keywords from the catch-all file's front matter.
2. For each listed code:
   1. Extract the numeric portion, such as CS0463 to 463.
   2. Find the ERR_ or WRN_ constant assigned that number in ErrorCode.cs.
   3. Find the <data> element in CSharpResources.resx whose name exactly matches the constant.
   4. Read the verbatim message from its <value> child.
3. Keep only messages related to the theme.
4. Exclude codes already present in the destination.

Present the filtered list and stop:

| Error Code | Error Message |
|------------|---------------|
| CS0463 | Evaluation of the decimal constant expression failed |
| CS1021 | Integral constant is too large |

Tell the user:

Review this list. Tell me which error codes to add.

Wait for explicit approval before proceeding to Phase C.

Phase C: Add Approved Error Codes

Process all approved codes as one batch.

For each code:

1. Add it to destination f1_keywords and helpviewer_keywords in numeric order.

2. Add it to the destination master error list in numeric order:

   - [**CS{NNNN}**](#anchor-tbd): *{verbatim error message from CSharpResources.resx}*

   Use #anchor-tbd until the consolidation phase assigns thematic anchors. Replace Roslyn format placeholders such as '{0}' and '{1}' with descriptive terms while preserving the static message text and producing a coherent sentence. Prefer context-appropriate generic terms such as 'type', 'value', 'operator', 'member', or 'method'. For example, Constant value '{0}' cannot be converted to a '{1}' becomes Constant value 'value' cannot be converted to a 'type'. Use the following XML <comment> element, when present, to identify placeholder meanings.

3. Add it to the destination TOC entry's displayName in numeric order.

4. Remove it from f1_keywords in the catch-all file.

Do not create redirects for these codes because they had no standalone articles.

Present a summary of all changes made.