procyberian/emacs
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Omit unnecessary history from Lisp intro

Browse source 
* doc/lispintro/emacs-lisp-intro.texi (Review, Digression into C)
(Conclusion): Reword so as not to talk about earlier versions
of Emacs in what should be an intro.
This commit is contained in:
Paul Eggert 2016-01-31 17:31:23 -08:00
parent 2fbd1dabeb
commit 43cb9f8ff3
1 changed files with 10 additions and 34 deletions
Download patch file Download diff file Expand all files Collapse all files

44
doc/lispintro/emacs-lisp-intro.texi
View file

@ -4309,38 +4309,18 @@ documentation, an optional interactive declaration, and the body of
the definition. the definition.
@need 1250 @need 1250
For example, in an early version of Emacs, the function definition was For example, in Emacs the function definition of
as follows. (It is slightly more complex now that it seeks the first @code{dired-unmark-all-marks} is as follows.
non-whitespace character rather than the first visible character.)
@smallexample @smallexample
@group @group
(defun back-to-indentation () (defun dired-unmark-all-marks ()
"Move point to first visible character on line." "Remove all marks from all files in the Dired buffer."
(interactive) (interactive)
(beginning-of-line 1) (dired-unmark-all-files ?\r))
(skip-chars-forward " \t"))
@end group @end group
@end smallexample @end smallexample
@ignore
In GNU Emacs 22,
(defun backward-to-indentation (&optional arg)
"Move backward ARG lines and position at first nonblank character."
(interactive "p")
(forward-line (- (or arg 1)))
(skip-chars-forward " \t"))
(defun back-to-indentation ()
"Move point to the first non-whitespace character on this line."
(interactive)
(beginning-of-line 1)
(skip-syntax-forward " " (line-end-position))
;; Move back over chars that have whitespace syntax but have the p flag.
(backward-prefix-chars))
@end ignore
@item interactive @item interactive
Declare to the interpreter that the function can be used Declare to the interpreter that the function can be used
interactively. This special form may be followed by a string with one interactively. This special form may be followed by a string with one
@ -9123,13 +9103,12 @@ deleted@footnote{More precisely, and requiring more expert knowledge
to understand, the two integers are of type @code{Lisp_Object}, which can to understand, the two integers are of type @code{Lisp_Object}, which can
also be a C union instead of an integer type.}. also be a C union instead of an integer type.}.
In early versions of Emacs, these two numbers were thirty-two bits Integer widths depend on the machine, and are typically 32 or 64 bits.
long, but the code is slowly being generalized to handle other A few of the bits are used to specify the type of information; the
lengths. Three of the available bits are used to specify the type of remaining bits are used as content.
information; the remaining bits are used as content.
@samp{XINT} is a C macro that extracts the relevant number from the @samp{XINT} is a C macro that extracts the relevant number from the
longer collection of bits; the three other bits are discarded. longer collection of bits; the type bits are discarded.
@need 800 @need 800
The command in @code{delete-and-extract-region} looks like this: The command in @code{delete-and-extract-region} looks like this:
@ -18724,10 +18703,7 @@ Even though it is short, @code{split-line} contains expressions
we have not studied: @code{skip-chars-forward}, @code{indent-to}, we have not studied: @code{skip-chars-forward}, @code{indent-to},
@code{current-column} and @code{insert-and-inherit}. @code{current-column} and @code{insert-and-inherit}.
Consider the @code{skip-chars-forward} function. (It is part of the Consider the @code{skip-chars-forward} function.
function definition for @code{back-to-indentation}, which is shown in
@ref{Review, , Review}.)
In GNU Emacs, you can find out more about @code{skip-chars-forward} by In GNU Emacs, you can find out more about @code{skip-chars-forward} by
typing @kbd{C-h f} (@code{describe-function}) and the name of the typing @kbd{C-h f} (@code{describe-function}) and the name of the
function. This gives you the function documentation. function. This gives you the function documentation.