ibp-field-def represents the
definition of one field in the record tail.
The “constructor” for a field definition object has this syntax:
the field's length in characters, and
is the default content.
The accessor functions are:
Returns the field's length.
Returns the field's default content.
Here is the constructor. It takes the two arguments and
assembles them into an emacs vector object (basically a
linear array) with the
;; - - - - - c l a s s i b p - f i e l d - d e f (defun ibp-field-def (len filler) "Constructor for a ibp-field-def, representing one field definition [ if (len is the length of a field as a positive integer) and (filler is the default content of the field, or nil if its default content is blank) -> return a ibp-field-def representing those values ] " (vector len filler))
There are two accessor functions. They access the
attributes of the object by position: the
len attribute is at position 0, and the
filler attribute is at position 1. The
elt function is a built-in function that takes
two arguments, a sequence and a position, and returns the
element of that sequence at that position.
(defun ibp-field-def-len (field-def) (elt field-def 0)) (defun ibp-field-def-filler (field-def) (elt field-def 1))