Major modes specialize Emacs for editing particular kinds of text. Each buffer has only one major mode at a time.
(Info-goto-node "(elisp)Major Modes")
include sig ... end
val sexp_of_t : t ‑> Base.Sexp.t
val syntax_table : t ‑> Syntax_table.t
val define_derived_mode : ?parent:t ‑> Core_kernel.Source_code_position.t ‑> change_command:Symbol.t ‑> docstring:string ‑> initialize:(unit ‑> unit) ‑> mode_line:string ‑> t
(describe-function 'define-derived-mode)
(Info-goto-node "(elisp)Derived Modes")