Function: coding-system-p
coding-system-p is a function defined in coding.c.
Signature
(coding-system-p OBJECT)
Documentation
Return t if OBJECT is nil or a coding-system.
See the documentation of define-coding-system for information
about coding-system objects.
Probably introduced at or before Emacs version 20.1.
Source Code
// Defined in /usr/src/emacs/src/coding.c
{
if (NILP (object)
|| CODING_SYSTEM_ID (object) >= 0)
return Qt;
if (! SYMBOLP (object)
|| NILP (Fget (object, Qcoding_system_define_form)))
return Qnil;
return Qt;
}