Parse the LNA rates so they can be compiled.
parse_lna_rates(
lna_rates,
param_codes,
const_codes,
tcovar_codes,
lna_comp_codes
)
character vector of LNA rates
named numeric vector of parameter codes
named numeric vector of constant codes
named numeric vector of time-varying covariate codes
named numeric vector of LNA compartment codes
string snippets for the LNA that can be compiled