2014-05-27 Glenn Morris <rgm@gnu.org>
+ * text.texi (Buffer Contents):
+ Update for filter-buffer-substring changes.
+
* abbrevs.texi (Abbrev Expansion): Update for expand-abbrev changes.
* functions.texi (Advising Functions): Standardize menu case.
completion-list-insert-choice-function
deactivate-current-input-method-function
describe-current-input-method-function
-filter-buffer-substring-functions
font-lock-function
menu-bar-select-buffer-function
read-file-name-function
@end defun
@defun filter-buffer-substring start end &optional delete
-This function passes the buffer text between @var{start} and @var{end}
-through the filter functions specified by the wrapper hook
-@code{filter-buffer-substring-functions}, and returns the result. The
-obsolete variable @code{buffer-substring-filters} is also consulted.
-If both of these variables are @code{nil}, the value is the unaltered
-text from the buffer, i.e., what @code{buffer-substring} would
-return.
-
-If @var{delete} is non-@code{nil}, this function deletes the text
+This function filters the buffer text between @var{start} and @var{end}
+using a function specified by the variable
+@code{filter-buffer-substring-function}, and returns the result.
+
+The default filter function consults the obsolete wrapper hook
+@code{filter-buffer-substring-functions}, and the obsolete variable
+@code{buffer-substring-filters}. If both of these are @code{nil}, it
+returns the unaltered text from the buffer, i.e., what
+@code{buffer-substring} would return.
+
+If @var{delete} is non-@code{nil}, the function deletes the text
between @var{start} and @var{end} after copying it, like
@code{delete-and-extract-region}.
@code{buffer-substring-no-properties},
or @code{delete-and-extract-region} when copying into user-accessible
data structures such as the kill-ring, X clipboard, and registers.
-Major and minor modes can add functions to
-@code{filter-buffer-substring-functions} to alter such text as it is
-copied out of the buffer.
+Major and minor modes can modify @code{filter-buffer-substring-function}
+to alter such text as it is copied out of the buffer.
@end defun
-@c FIXME: `filter-buffer-substring-function' should be documented.
+@defvar filter-buffer-substring-function
+The value of this variable is a function that @code{filter-buffer-substring}
+will call to do the actual work. The function receives three
+arguments, the same as those of @code{filter-buffer-substring},
+which it should treat as per the documentation of that function. It
+should return the filtered text (and optionally delete the source text).
+@end defvar
+
+@noindent The following two variables are obsoleted by
+@code{filter-buffer-substring-function}, but are still supported for
+backward compatibility.
+
@defvar filter-buffer-substring-functions
-This variable is a wrapper hook (@pxref{Running Hooks}), whose members
-should be functions that accept four arguments: @var{fun},
-@var{start}, @var{end}, and @var{delete}. @var{fun} is a function
-that takes three arguments (@var{start}, @var{end}, and @var{delete}),
-and returns a string. In both cases, the @var{start}, @var{end}, and
-@var{delete} arguments are the same as those of
-@code{filter-buffer-substring}.
+This obsolete variable is a wrapper hook, whose members should be functions
+that accept four arguments: @var{fun}, @var{start}, @var{end}, and
+@var{delete}. @var{fun} is a function that takes three arguments
+(@var{start}, @var{end}, and @var{delete}), and returns a string. In
+both cases, the @var{start}, @var{end}, and @var{delete} arguments are
+the same as those of @code{filter-buffer-substring}.
The first hook function is passed a @var{fun} that is equivalent to
the default operation of @code{filter-buffer-substring}, i.e., it
@end defvar
@defvar buffer-substring-filters
-This variable is obsoleted by
-@code{filter-buffer-substring-functions}, but is still supported for
-backward compatibility. Its value should should be a list of
-functions which accept a single string argument and return another
-string. @code{filter-buffer-substring} passes the buffer substring to
-the first function in this list, and the return value of each function
-is passed to the next function. The return value of the last function
-is passed to @code{filter-buffer-substring-functions}.
+The value of this obsolete variable should be a list of functions
+that accept a single string argument and return another string.
+The default @code{filter-buffer-substring} function passes the buffer
+substring to the first function in this list, and the return value of
+each function is passed to the next function. The return value of the
+last function is passed to @code{filter-buffer-substring-functions}.
@end defvar
@defun current-word &optional strict really-word
*** `generic-make-keywords-list'
*** `get-upcase-table' (use `case-table-get-table' instead).
++++
** `with-wrapper-hook' is obsoleted by `add-function'.
The few hooks that used with-wrapper-hook are replaced as follows:
*** `abbrev-expand-function' obsoletes `abbrev-expand-functions'.
2014-05-27 Glenn Morris <rgm@gnu.org>
+ * simple.el (filter-buffer-substring-functions)
+ (filter-buffer-substring-function, buffer-substring-filters)
+ (filter-buffer-substring, buffer-substring--filter): Doc fixes.
+
* minibuffer.el (completion-in-region-functions, completion-in-region)
(completion--in-region): Doc fixes.
\f
(defvar filter-buffer-substring-functions nil
- "This variable is a wrapper hook around `filter-buffer-substring'.")
+ "This variable is a wrapper hook around `buffer-substring--filter'.")
(make-obsolete-variable 'filter-buffer-substring-functions
'filter-buffer-substring-function "24.4")
(defvar filter-buffer-substring-function #'buffer-substring--filter
"Function to perform the filtering in `filter-buffer-substring'.
-The function is called with 3 arguments:
-\(BEG END DELETE). The arguments BEG, END, and DELETE are the same
-as those of `filter-buffer-substring' in each case.
-It should return the buffer substring between BEG and END, after filtering.")
+The function is called with the same 3 arguments (BEG END DELETE)
+that `filter-buffer-substring' received. It should return the
+buffer substring between BEG and END, after filtering. If DELETE is
+non-nil, it should delete the text between BEG and END from the buffer.")
(defvar buffer-substring-filters nil
- "List of filter functions for `filter-buffer-substring'.
-Each function must accept a single argument, a string, and return
-a string. The buffer substring is passed to the first function
-in the list, and the return value of each function is passed to
-the next.
+ "List of filter functions for `buffer-substring--filter'.
+Each function must accept a single argument, a string, and return a string.
+The buffer substring is passed to the first function in the list,
+and the return value of each function is passed to the next.
As a special convention, point is set to the start of the buffer text
-being operated on (i.e., the first argument of `filter-buffer-substring')
+being operated on (i.e., the first argument of `buffer-substring--filter')
before these functions are called.")
(make-obsolete-variable 'buffer-substring-filters
'filter-buffer-substring-function "24.1")
(defun filter-buffer-substring (beg end &optional delete)
"Return the buffer substring between BEG and END, after filtering.
-The hook `filter-buffer-substring-function' performs the actual filtering.
-By default, no filtering is done.
-
-If DELETE is non-nil, the text between BEG and END is deleted
-from the buffer.
-
-This function should be used instead of `buffer-substring',
-`buffer-substring-no-properties', or `delete-and-extract-region'
-when you want to allow filtering to take place. For example,
-major or minor modes can use `filter-buffer-substring-function' to
-extract characters that are special to a buffer, and should not
-be copied into other buffers."
+If DELETE is non-nil, delete the text between BEG and END from the buffer.
+
+This calls the function that `filter-buffer-substring-function' specifies
+\(passing the same three arguments that it received) to do the work,
+and returns whatever it does. The default function does no filtering,
+unless a hook has been set.
+
+Use `filter-buffer-substring' instead of `buffer-substring',
+`buffer-substring-no-properties', or `delete-and-extract-region' when
+you want to allow filtering to take place. For example, major or minor
+modes can use `filter-buffer-substring-function' to extract characters
+that are special to a buffer, and should not be copied into other buffers."
(funcall filter-buffer-substring-function beg end delete))
(defun buffer-substring--filter (beg end &optional delete)
+ "Default function to use for `filter-buffer-substring-function'.
+Its arguments and return value are as specified for `filter-buffer-substring'.
+This respects the wrapper hook `filter-buffer-substring-functions',
+and the abnormal hook `buffer-substring-filters'.
+No filtering is done unless a hook says to."
(with-wrapper-hook filter-buffer-substring-functions (beg end delete)
(cond
((or delete buffer-substring-filters)
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