buffer-substring--filter

buffer-substring--filter is a compiled Lisp function in `simple.el'.

(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.