Speed Converter

A modern Fortran project using FPM (Fortran Package Manager) to convert between km/h and mph.

Note

This project was created as my introduction to Fortran.
It’s a small but complete example that uses modern Fortran features, modular design, and unit testing.

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✨ Features

• 🔄 Convert from km/h → mph and mph → km/h
• 🖥 Interactive command-line interface
• 🧪 Comprehensive unit tests for accuracy
• 📦 Structured for FPM (Fortran Package Manager)
• ✅ Written with explicit interfaces and implicit none

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🛠 Prerequisites

• gfortran (GNU Fortran compiler)
• FPM (FPM build/run support is in progress – see below for manual build steps)

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🚀 Building and Running

Caution

FPM support is being worked on.
For now, please build manually with gfortran.

Build and Run (Manual)

# Build the conversion module
gfortran -c src/convert.f90 -J build

# Build the main application
gfortran -c app/main.f90 -I build
gfortran -o speed-converter convert.o main.o

# Run the application
./speed-converter

Build and Run Tests (Manual)

# Build tests
gfortran -c test/test_convert.f90 -I build
gfortran -o test_runner convert.o test_convert.o

# Run tests
./test_runner

FPM Commands (Coming Soon)

# Will be available once FPM setup is complete
# fpm run
# fpm test
# fpm build

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📖 Usage

When running the application, enter a speed value followed by the unit:

Enter speed value and unit (e.g., "100 kmh" or "60 mph"): 100 kmh
100.00 km/h = 62.14 mph

Supported units:

• kmh or km/h → kilometers per hour
• mph → miles per hour

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📂 Project Structure

speed-converter/
├── fpm.toml              # FPM configuration
├── src/
│   └── convert.f90       # Conversion functions module
├── app/
│   └── main.f90          # Main application
├── test/
│   └── test_convert.f90  # Unit tests
└── README.md             # This file

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📐 Conversion Formula

The project uses the standard factor:
1 km/h = 0.621371 mph

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🧪 Testing

The included tests verify:

• ✅ Conversion accuracy with known values
• ✅ Edge cases (e.g., zero values)
• ✅ Round-trip conversions
• ✅ Reciprocal relationships

Run tests:

# Manual method
gfortran -c test/test_convert.f90 -I build
gfortran -o test_runner convert.o test_convert.o
./test_runner

# With FPM (coming soon)
# fpm test