Ppx_css_syntax.String_constantSourcetype t = {css_string : string;string_loc : Ppxlib.location;Equivalent to where the "stylesheet" identifier is located from within the call to ppx_css. This is used to potentially give merlin information for MerlinTypeOf to know the type of the stylesheet function.
delimiter : string option;}String_constant.t represents an OCaml string constant from ppxlib's AST.
from ppxlib's docs:
Constant string such as ["constant"]
[{delim|other constant|delim}].
The location span the content of the string, without the delimiters.