Identifiers that are target-language keywords are emitted verbatim: a property named Type or Default generates `fn type(...)` (Rust) / `int default()` (C++) that fails to compile

[matt-edmondson]

What's wrong

No generator checks a spelled identifier against the target language's reserved words. LanguageGeneratorBase and the language generators have no reserved-word set, and names only go through NameStyles.Spell (re-casing). The AST is language-neutral, so a name that is perfectly legal in one target becomes a keyword in another once re-cased. The clearest case is the getter name made up for a computed property, PropertyDeclaration.GetterName (Coder/Ast/PropertyDeclaration.cs ~141), used from StandardLanguageGenerator.cs ~393:

Repro (reproduced with MSTest, output checked with the real compilers)

A struct Box with new PropertyDeclaration("Type", "int") and new PropertyDeclaration("Default", "int"), each with a getter body return 1. Both are ordinary C# property names.

Target	Generated	Compiler
Rust	pub fn type(&self) -> i32	rustc: expected identifier, found keyword 'type'
C++	int default() const	g++ -std=c++20: expected unqualified-id before 'default'
C	Box_type	fine, because of the prefix

The same applies to any other spelled identifier (parameter, local, field, function) that lands on a keyword after casing, e.g. match/impl/fn in Rust, range/func/type in Go, lambda/def in Python, delete/new in C++.

This is independent of #71: ktsu.CaseConverter would still produce type.

Suggested fix / acceptance criteria

• Give each generator a reserved-word set and a single EscapeIdentifier hook applied wherever a name is spelled:
  • Rust: raw identifiers (r#type). Note that self/Self/crate/super can't be raw, so suffix those.
  • C++/C/Go/Python/JS: append _ (e.g. default_, type_).
  • C#: @default.
• Apply it consistently at declaration and use sites so references still resolve.
• Add compile tests with a property named Type/Default and a parameter named after a keyword in each target.

[matt-edmondson]

Triage

• Category: Bug
• Priority: High. Ordinary, idiomatic C# names (Type, Default, Match, Range, Delete, …) produce Rust and C++ output that doesn't compile, and the same gap exists across every target language. For a multi-target code generator this is a systemic correctness hole, not an edge case, because no generator has a reserved-word list at all.
• Area / suggested assignee: LanguageGeneratorBase (a new EscapeIdentifier hook and a per-language reserved-word set), NameStyles.Spell call sites, and PropertyDeclaration.GetterName. Owner: @matt-edmondson
• Duplicates / in progress: not a duplicate. As the issue notes, it is independent of Delegate naming-style spelling to ktsu.CaseConverter #71 (CaseConverter adoption). No open PR in Coder covers it.
• Next step: add the escaping at one choke point, wherever a name is spelled, so declaration and use sites can't drift apart. Start with Rust (r#, suffixing self/Self/crate/super) and C++, where the repro fails. Then roll it out to Go, Python, JS, C and C#, with a compile test per target covering a keyword-named property and parameter.

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Generated by Claude Code