# issue-02-compiler-dead-code-removal: Remove Unused functions Field from Compiler Struct

## Description
Remove the unused `functions` HashMap field from the Compiler struct and its initialization. This field is declared at line 88 and initialized at line 104 but is never read after initialization, triggering dead code warnings. Pre-verify no usage exists before removal.

## Architecture Reference
Read `/Users/santoshkumarradha/Documents/agentfield/code/int-agentfield-examples/af-swe/example-pyrust/.artifacts/plan/architecture.md` Section "Component 2: Dead Code Removal - compiler.rs functions Field" for:
- Pre-implementation verification strategy using `grep -n "self\.functions"`
- Exact line numbers for field declaration (88) and initialization (104)
- Comment placement guidance for documenting removal

## Interface Contracts
- **Implements**: Removal of dead code field from internal struct
- **Signature**:
```rust
// Remove from struct (line 88):
functions: HashMap<String, (usize, usize, u8)>,

// Remove from constructor (line 104):
functions: HashMap::new(),
```
- **Exports**: Clean Compiler struct with no unused fields
- **Consumes**: Current compiler.rs implementation
- **Consumed by**: issue-04-compiler-len-zero-fix (depends on this completing first)

## Isolation Context
- **Available**: None (foundation component)
- **NOT available**: All sibling Phase 1 components
- **Source of truth**: Architecture document Component 2 interface specification

## Files
- **Modify**: `src/compiler.rs` (remove lines 88, 104; add explanatory comment)

## Dependencies
- None (can run in parallel with Components 1, 3, 6, 7, 8, 9)

## Provides
- Compiler struct with unused functions field removed
- Elimination of functions field dead code warning

## Acceptance Criteria
- [ ] `cargo build --lib 2>&1 | grep -c "field.*functions.*never read"` outputs 0
- [ ] `cargo build --lib 2>&1` exits with code 0 (compilation succeeds)
- [ ] `grep -n "self\.functions" src/compiler.rs` shows no usages beyond removed lines

## Testing Strategy

### Test Files
- No new test files; verified through compilation and warning checks

### Test Categories
- **Pre-verification**: `grep -n "self\.functions" src/compiler.rs` confirms field is truly unused
- **Build verification**: `cargo build --lib` confirms no compilation errors after removal
- **Warning verification**: Confirms dead code warning disappears

### Run Command
`cargo build --lib 2>&1 | grep "functions"`

## Verification Commands
- Build: `cargo build --lib 2>&1`
- Warning check: `cargo build --lib 2>&1 | grep -c "field.*functions.*never read"` (expect: 0)
- Usage check: `grep -n "self\.functions" src/compiler.rs` (expect: no output or only removed lines)
