Migrate error deduplication to node-ID based approach, fixes #71

[Arowolokehinde]

Fixes #71
Fixes #108

Summary

Migrates the type checker's error deduplication system from string-based keys to more efficient node-ID based approach using FxHashSet<(ErrorKind, u32)>.

Changes

Added

• ErrorKind enum in core/type-checker/src/errors.rs

  • Categorizes the 5 error types that require deduplication
  • UnknownType, UndefinedFunction, UnknownIdentifier, UndefinedStruct, UndefinedEnum

• kind() method on TypeCheckError

  • Returns Option<ErrorKind> for errors that need deduplication
  • Returns None for other error types

Modified

• TypeChecker struct (core/type-checker/src/type_checker.rs)

  • Changed field: reported_error_keys: FxHashSet<String> → reported_errors: FxHashSet<(ErrorKind, u32)>

• push_error_dedup signature

  • Now accepts node_id: u32 parameter
  • Uses (ErrorKind, u32) tuple as deduplication key

• 7 call sites updated to pass node IDs:

  • Generic type base validation (line 443)
  • Generic type parameter validation (line 454)
  • Custom type validation (line 468)
  • Enum definition validation (line 963)
  • Function call validation (line 1203)
  • Struct expression validation (line 1305)
  • Identifier validation (line 1525)

• 3 test expectations updated for new behavior:

  • test_error_deduplication_same_unknown_type_multiple_uses: 1 → 4 errors
  • test_error_deduplication_same_undefined_function_multiple_calls: 1 → 2 errors
  • test_error_deduplication_same_unknown_identifier_multiple_uses: 1 → 3 errors

Testing

• ✅ All type-checker unit tests pass (71 tests)
• ✅ Build succeeds: cargo build -p inference-type-checker
• ✅ Test expectations updated to reflect new behavior
• ✅ No breaking changes to public API (all changes are internal)

Files Modified

• core/type-checker/src/errors.rs - Added ErrorKind enum and kind() method
• core/type-checker/src/type_checker.rs - Updated deduplication logic and call sites
• tests/src/type_checker/error_recovery.rs - Updated test expectations
• implemenration.md - Added implementation documentation

cargo build -p inference-type-checker
cargo test -p inference-type-checker

---

Changes

Added

• ErrorKind enum - Categorizes 5 error types needing deduplication
• kind() method on TypeCheckError - Returns error category

Modified

• TypeChecker field: FxHashSet<String> → FxHashSet<(ErrorKind, u32)>
• push_error_dedup now accepts node_id: u32 parameter
• 7 call sites updated to pass node IDs
• 3 test expectations updated for new behavior

EOF

[Arowolokehinde]

@0xGeorgii can you kindly review my pr

[Arowolokehinde]

@0xGeorgii can you kindly review my pr