# Task Summary: End-to-End Module System Examples

## Objective
Add clear end-to-end examples demonstrating Ape v0.2.0's module system, imports, and standard library usage for documentation and manual sanity checks.

## What Was Created

### 1. New Example Programs

#### `examples/hello_imports.ape`
- **Purpose:** Basic demonstration of stdlib imports (sys, math)
- **Features:**
  - Module declaration: `module main`
  - Imports: `import sys`, `import math`
  - Calls: `math.add()`, `math.multiply()`, `sys.print()`
  - Entity, tasks, and flow demonstrating complete program structure
- **Status:** ✅ Parses, validates, and builds successfully

#### `examples/stdlib_complete.ape`
- **Purpose:** Comprehensive example using all three stdlib modules
- **Features:**
  - Imports: `import sys`, `import io`, `import math`
  - Uses `io.read_file()`, `io.write_file()`, `io.read_line()`
  - Uses `math.multiply()` for calculations
  - Uses `sys.print()` for output
  - Demonstrates file processing workflow
- **Status:** ✅ Parses, validates, and builds successfully

#### `examples/custom_lib_project/`
- **Purpose:** Demonstrates local library organization with `lib/` folder
- **Structure:**
  ```
  custom_lib_project/
  ├── main.ape           # Entry point (imports tools)
  └── lib/
      └── tools.ape      # Local library module
  ```
- **Features:**
  - `tools.ape` declares `module tools` with utility functions
  - `main.ape` imports both stdlib and local library: `import sys`, `import tools`
  - Demonstrates linker's lib/ resolution priority
  - Shows how local modules can depend on stdlib
- **Status:** ✅ Parses, validates, and builds successfully

### 2. Documentation

#### `examples/MODULES_README.md`
- Comprehensive guide to all module system examples
- Module resolution rules explained
- Standard library API reference (sys, io, math)
- Usage instructions for each example
- Examples of how to create your own modules

#### Updated `README.md`
- Added "Try the Module System Examples (v0.2.0)" section
- Commands to validate and build all new examples
- Reference to detailed module documentation

### 3. Test Suite

#### `tests/examples/test_module_examples.py` (15 new tests)
- **TestHelloImportsExample (5 tests):**
  - Existence, parsing, import verification
  - Linking verification
  - Complete compilation pipeline
  
- **TestStdlibCompleteExample (3 tests):**
  - Verifies imports of all stdlib modules
  - Linking verification
  - Compilation verification
  
- **TestCustomLibProjectExample (5 tests):**
  - Project structure validation
  - Local library import verification
  - Linker resolution from lib/ folder
  - Module parsing
  - Complete compilation pipeline
  
- **TestExamplesIntegration (2 tests):**
  - All examples exist
  - All examples are valid Ape programs

## Testing Results

### Initial Testing
✅ All examples validate successfully:
```bash
python -m ape validate examples/hello_imports.ape       # OK
python -m ape validate examples/stdlib_complete.ape     # OK
python -m ape validate custom_lib_project/main.ape      # OK
```

✅ All examples build successfully:
```bash
python -m ape build examples/hello_imports.ape          # 3 files generated
python -m ape build examples/stdlib_complete.ape        # 4 files generated
python -m ape build custom_lib_project/main.ape         # 4 files generated
```

### Test Suite Results
- **New tests:** 15 tests for module examples
- **Total tests:** 192 tests (177 existing + 15 new)
- **Status:** ✅ **192/192 passing**

## Verification Commands

Users can now run:

```bash
# Validate examples
python -m ape validate examples/hello_imports.ape
python -m ape validate examples/stdlib_complete.ape
cd examples/custom_lib_project && python -m ape validate main.ape

# Build examples
python -m ape build examples/hello_imports.ape --target=python
python -m ape build examples/stdlib_complete.ape --target=python
python -m ape build examples/custom_lib_project/main.ape --target=python

# Parse and IR
python -m ape parse examples/hello_imports.ape
python -m ape ir examples/hello_imports.ape

# Run tests
python -m pytest tests/examples/test_module_examples.py -v
```

## Key Features Demonstrated

1. **Module Declarations:** Every example properly declares its module name
2. **Standard Library Usage:** All three stdlib modules (sys, io, math) are demonstrated
3. **Local Libraries:** Shows how to organize code in lib/ folders
4. **Import Resolution:** Demonstrates deterministic search order (lib/ → . → ape_std/)
5. **Qualified Calls:** Examples show `math.add()`, `sys.print()`, etc.
6. **Name Mangling:** Generated code properly mangles to `math__add`, `sys__print`, etc.
7. **Complete Pipelines:** All examples can parse → link → build → generate Python

## Files Created/Modified

**New files (7):**
- `examples/hello_imports.ape` - Basic stdlib imports example
- `examples/stdlib_complete.ape` - Complete stdlib usage example
- `examples/custom_lib_project/main.ape` - Local library project main
- `examples/custom_lib_project/lib/tools.ape` - Local library module
- `examples/MODULES_README.md` - Comprehensive examples documentation
- `tests/examples/test_module_examples.py` - Test suite for examples

**Modified files (1):**
- `README.md` - Added section on running module system examples

## Success Criteria Met

✅ **Clear end-to-end examples** - Three different examples covering various use cases  
✅ **Module system demonstration** - Module declarations and imports shown  
✅ **Standard library usage** - All three stdlib modules (sys, io, math) demonstrated  
✅ **Local lib/ folder** - custom_lib_project shows organization  
✅ **Documentation** - Comprehensive MODULES_README.md created  
✅ **README updated** - Easy-to-follow instructions added  
✅ **Tested** - 15 new tests ensure examples remain valid  
✅ **All tests passing** - Full test suite: 192/192 ✅

## Impact

These examples provide:
1. **Learning resource** for new Ape users
2. **Documentation reference** for module system features
3. **Manual testing** capability for sanity checks
4. **Regression testing** via automated test suite
5. **Real-world patterns** for organizing Ape projects

The examples complement the existing calculator and email policy examples by focusing specifically on the new v0.2.0 module system features.
