Latexify.jl

In case people would like similar functionality in the Julia programming language, there is also a package for that: https://github.com/korsbo/Latexify.jl

That was the strength of Lisp as the original 'AI' language, but the following AI summer were always more numerical oriented (neural networks, bayesian inference, SVM, neural networks part 2), so that particular strength was not very needed. And in the end the most important killer feature of an 'AI' language ended up being approachable and easy to use, and not the "power", which is why Julia goes with the "Looks like Python, feels like Lisp, runs like Fortran". And like you said, even without s-expr you can do it with macros (especially in a homoiconic language like Julia), for example: https://github.com/chakravala/Reduce.jl https://github.com/korsbo/Latexify.jl

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).

Julia is notably missing. Packages like this one are dope https://github.com/korsbo/Latexify.jl Or this https://github.com/qojulia/QuantumOptics.jl Or this https://www.juliahomotopycontinuation.org/