For declarative languages, specifically (but not limited to) in the field of modelling, it's not obvious to me whether code can be considered to be separate from data. This line of reasoning may only apply to non-turing complete languages such as NeuroML.Say for instance I had a very domain specific declarative language which I used to described the positions of planets and their velocities, and I described a system of three orbiting bodies:satellite planet_earth,moon,sun {planet_earth.position = [6,0,0]planet_earth.velocity = [0,23,-32]planet_earth.mass = 1e3moon.position = [6,0,0.0001]moon.velocity = [0,0,3]moon.mass = 1e2sun.position = [0,0,0]sun.velocity = [0,0,0]sun.mass = 1e12 }This language could be passed to a simulator which then simulated the motion of the planets.From one perspective this is code - It is describing initial conditions and consequently within the constraints of the language a sequence of steps for a computer to run. From another perspective it is 'data' - it is a description of a physical system.Is this concept (is something code or data) something which has been studied much? I've looked into it 
In a declarative language, specifically in the context of modelling, can we make a clear distinction between code and data?
modelling;declarative programming;declarative