FlightLang Docs

Install

FlightLang provides a CLI that compiles .fl into runnable code.

# Python backend (run directly)
python -m flightlang.cli run examples/survey.fl

# Build to a standalone Python file
python -m flightlang.cli build examples/survey.fl -o out.py
python out.py

# Generate a Rust crate (Cargo project)
python -m flightlang.cli build examples/survey.fl --backend rust --outdir mission_rs
cd mission_rs && cargo run

Hello mission

mission Hello {
  state Idle {
    on arm -> Takeoff
  }
  state Takeoff {
    action climb_to(20 m)
    on reached_altitude -> RTL
  }
  state RTL {
    action return_to_launch()
    on landed -> Done
  }
  state Done { }
}

Run it with python -m flightlang.cli run hello.fl.

Syntax

• Variables with units: let cruise_alt: m = 60 m
• States contain actions, transitions, and optional deadlines.
• Expressions support numbers, strings, identifiers, and simple calls (e.g., waypoint_grid(...)).

Actions & events

Actions map to platform behaviors; events trigger transitions:

Events are user-defined (e.g., arm, reached_altitude, grid_complete).

Backends

• Python: generates runnable Python with a tiny runtime for deterministic simulation.
• Rust: generates a Cargo project with action stubs; integrate with PX4/ROS 2 as needed.

Roadmap & safety

• Static analysis for unreachable states and unsafe transitions
• Formal safety contracts (timing, geofence compliance)
• Full MAVSDK/ROS 2 integration
• LSP + editor tooling

Status: Early Alpha. Not flight-certified.