[ddragon]

Julia (a language focused on science/math) does it partially. For example in the editor or REPL you can just type \sqrt [tab] \alpha [tab] and it will generate √α which is valid code. Most math symbols in unicode are supported and overloadable. And you can also write matrix like a table, such as

[1 2 3

4 5 6

7 8 9].

And you can transform Julia expressions to LaTeX:

https://github.com/korsbo/Latexify.jl

But even they didn't go as far as being able to parse full LaTeX expressions (though you technically could with reader macros plus editor support).