问题
I am aware of the wikipedia page on SEXP, and I know that it stands for symbolic expression. I know (vaguely) SEXP is notation to refer to tree data structures in Lisp, but I want to know what motivated the developers to call the data type of R objects in C SEXP. Why SEXP?
I am also confused because if R was made in C and Fortran, why would notation from Lisp be used? Or is SEXP a more general term? Maybe I'm missing something here.
回答1:
R is, internally, kind of like Scheme with an S-compatible syntax. A lot of R's internals derive from Scheme concepts, like cons cells and lexical environments.
Back in the late 90s, I worked on a new (at the time) serialisation format for R; see my honours project paper, which explains a lot of this. (The email address on that paper isn't valid any more, so don't use that.)
来源：https://stackoverflow.com/questions/38177777/what-exactly-is-the-sexp-data-type-in-rs-c-api-and-why-is-it-used