A domain-specific language for Gazebo simulation scripting.

gzScript is an experimental DSL (domain-specific language) designed to make working with Gazebo easier and more intuitive. gzScript aims to provide:

• Strongly typed quantities and units (SI-first, safe conversions).
• A clean syntax for describing models, poses, joints, and animations.
• An approachable scripting language for simulation experiments.
• A foundation for higher-level workflows (model design, control, testing).

Gazebo is powerful, but SDF and plugin code can be verbose and error-prone. gzScript explores whether we can design a friendlier layer on top, without losing rigor.

Goals:

• Reduce boilerplate.
• Prevent unit errors.
• Enable “sketching” of simulation ideas quickly.
• Stay interoperable with Gazebo ecosystem.

First things first. To model physical systems legibly requires strongly typed physical quantities. Work has been ongoing, notably in C++, for example in pqs, quan and mp-units, to provide a semantic for representing physical quanties in an expressive way.
gzScript provides an opportunity to enshrine physical quantities in the language itself. C++ has the notion of a user defined literal. It is a nice idea, but very limited in practise. in c++ the literal is effectively in the global namespace and units can't be composed due to C++ syntax. in gzScript, units live in their own exclusive semantic space in which the rules of units only can be applied. The unit namespace is enterd and exited using the colon':' as follows :

// Quantities lvalues are constant by default
v = 5:m/s:;
t = 2:s:;
d = v * t;      // 10:m:

// Refined quantities
h:height: = 1.2:m:;
w:width:  = 0.3:m:;

// Declare a unit alias
mph = :mi/h:;

// Angle handling
var theta = 180:deg:;  // theta can be modified
phi   = 3.14:rad:;

theta = phi; // angle conversions

• Core principles for units & quantities
• Parser / grammar draft (Bison/Flex)
• Interpreter / compiler backend
• Gazebo integration (generate SDF / send commands)
• Example models and control scripts

Work in progress. This project is currently in early design stages. Contributions, ideas, and discussions are welcome.

• Gazebo
• mp-units
• pqs

TBD (MIT or Apache-2.0 recommended).