Change a function without the actual evaluation ...?

Hi.

I’d like to know if there is a way to convert a function to a different form without the actual evaluation.

For example, I’m trying to make an API of DifferentialEquations.jl. However, I encountered a serious performance degradation. The following code is an example of my API.

function DifferentialEquations.ODEProblem(env::AbstractEnv, f, x0, tspan; kwargs...)
    warn_is_registered(env)
    _x0 = raw(env, x0)
    _f(_x, p, t) = raw(env, f(readable(env, _x), p, t))
    ODEProblem(_f, _x0, tspan; kwargs...)
end

In the above code, x0 denotes NamedTuple-valued (i.e., readable) initial condition.
_x0 is a vector-valued (i.e., raw) initial condition.
From this line, _f(_x, p, t) = raw(env, f(readable(env, _x), p, t)), you may notice that the argument f of the extended function DifferentialEquations.ODEProblem(env::AbstractEnv, f, x0, tspan; kwargs...) will receive a “readable” state (x) and provide a “readable” output of its derivative.
For the compatibility with DifferentialEquations.jl, _f, which is the injected dynamical equations into ODEProblem provided by DifferentialEquations.jl, should provide a “raw” output, so the output of f(readable(env, _x), p, t) is wrapped by raw.

In this case, I realised that every call of _f would require two processings, raw and readable, which drastically degrade the performance. So, I wonder if there is a way of parsing the “readable” dynamical equations, f, to the “raw” dynamical equations, _f, at the beginning, not every time it is called.

LabelledArrays.jl resolves my issue. So I closed this conversation.

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