'can be implemented' is different from 'has been implemented'
how does unchained handle gaussian elimination
how does unchained handle gaussian elimination
if your static type system can't handle that, it can't handle unit types for basic linear algebra subroutines
Nim allows you to do a lot, e.g. derivatives of a unitful expression with measurement errors [0]. But other aspects run into the reality of dealing with a static type system. For example in Measuremancer [1], the library handling measurements with uncertainties, each `Measurement` is a single generic `Measurement[T]`. Each measurement stores the derivatives for error propagation. Obviously the derivatives have different units. Now, we could make `Measurement` a two-fold generic, `Measurement[T, U]`, but that just makes things more unwieldy in practice, for not much gain.
Without rewriting a majority of existing code you will always run into trouble where your perfect unit type system will either break or you'll need to work around it anyway (e.g. calling into some C library for part of the code).
you seem to be saying that it's impossible to formulate a type system that handles units correctly in contexts like generic linear algebra algorithms
i think you are mistaken about that
in the same way that pascal's type system handled array sizes 'incorrectly' because you couldn't write a subroutine that could operate on an array of any size, just arrays of one size or another
you could say 'yes, well, the code you write will have to be adapted in certain cases (compared to current existing implementations of string algorithms)', like say if your string has more than 20 characters in it, but the reason is that you're doing something the type system can't handle