# Analysis Limitations

**Generated**: 2025-02-02

## What Could Not Be Observed

### 1. Dynamic/Runtime Dependencies

- **Plugin loading**: Any runtime module loading via `dlopen` or similar
- **Reflection-based imports**: Dependencies resolved at runtime
- **Configuration-driven imports**: Modules loaded based on config values

### 2. Macro-Generated Code

- **Procedural macros**: Code generated by `#[derive(...)]` and custom proc macros
- **Declarative macros**: `macro_rules!` expansions that generate `use` statements
- **Build script outputs**: Code generated by `build.rs` files

### 3. Conditional Compilation

- **Platform-specific code**: `#[cfg(target_os = "...")]` blocks are included regardless of target
- **Feature flags**: `#[cfg(feature = "...")]` gated code is included unconditionally
- **Test-only code**: `#[cfg(test)]` modules are excluded from analysis

### 4. Re-exports and Transitive Dependencies

- **`pub use` chains**: Transitive re-exports are not fully traced
- **Glob imports**: `use module::*` does not enumerate specific items
- **Prelude imports**: Implicit prelude items are not tracked

### 5. External Crate Dependencies

- **Third-party crates**: Only internal g3 workspace crates are analyzed
- **Workspace dependency versions**: Version constraints not analyzed
- **Optional dependencies**: Not distinguished from required dependencies

## What Was Inferred

### 1. Module Hierarchy

Module parent-child relationships inferred from:
- `mod` declarations in `lib.rs` and `mod.rs` files
- File system structure (`foo/mod.rs` implies `foo` module)

**Confidence**: High - Rust module system is deterministic

### 2. Crate Dependencies

Crate-level dependencies extracted from:
- `Cargo.toml` `[dependencies]` sections
- `path = "..."` declarations for workspace crates

**Confidence**: High - Cargo.toml is authoritative

### 3. File-Level Imports

File imports extracted via regex pattern matching:
- `^use (g3_|crate::)` for internal imports
- `^(pub )?mod ` for module declarations

**Confidence**: Medium-High - May miss unusual import patterns

### 4. Fan-In/Fan-Out Counts

Coupling metrics derived from edge counts in dependency graph.

**Confidence**: Medium - Depends on completeness of edge extraction

## What May Invalidate Conclusions

### 1. Code Changes

This analysis reflects the codebase state at generation time. Any of the following invalidate the analysis:
- New files added
- Import statements changed
- Module structure reorganized
- Cargo.toml dependencies modified

### 2. Incomplete Extraction

The regex-based extraction may miss:
- Multi-line `use` statements with unusual formatting
- Imports inside function bodies
- Imports in macro invocations
- `extern crate` declarations (deprecated but valid)

### 3. Test Code Exclusion

Test files (`tests/*.rs`, `#[cfg(test)]` modules) are excluded. Test-only dependencies and coupling patterns are not reflected.

### 4. Example Code Exclusion

Example files (`examples/*.rs`) are excluded from the graph.

### 5. Build Script Dependencies

`build.rs` files may introduce compile-time dependencies not reflected in the import graph.

## Extraction Method Details

| Aspect | Method | Tool |
|--------|--------|------|
| Crate dependencies | Cargo.toml parsing | Manual inspection |
| Module declarations | Regex: `^(pub )?mod ` | ripgrep |
| Internal imports | Regex: `^use (g3_\|crate::)` | ripgrep |
| File enumeration | `find crates -name "*.rs"` | find |
| Cycle detection | Manual graph traversal | N/A |

## Recommendations for Future Analysis

1. **Use cargo metadata**: `cargo metadata --format-version 1` provides authoritative dependency information
2. **Use rust-analyzer**: LSP-based analysis would capture macro expansions
3. **Use cargo-depgraph**: Specialized tool for Rust dependency visualization
4. **Include test coverage**: Analyze test files separately for test-specific coupling