Introduction

CharRot provides a command charrot-replace' to replace the text before point with an arbitrary string, like the Emacs standard abbrev-mode'. There are two main differences with `abbrev-mode':

• Any text string can be defined as an abbreviation, not just words. (On the other hand, this means that CharRot cannot provide any case-matching feature: abbreviation and replacement are matched verbatim.)

• Replacement is not performed automatically but must be invoked by calling the command `charrot-replace'.

charrot-replace' scans the text *before* point; if it matches any abbreviation defined withcharrot-define-abbrev' or charrot-define-rotating', it will be replaced with the appropriate replacement string. The longest-matching string is replaced. Point is kept at the end of the replacement string -- thus, repeated application ofcharrot-replace' is possible. Undo works as usual, so any replacement can be undone with `C-_'.

Example usage

Load the file charrot.el::

+begin_src elisp

(require 'charrot)

+end_src

CharRot is most useful when charrot-replace' is bound to an easily accessible key chord; I useC-;` for that:

+begin_src elisp

(global-set-key (kbd "C-;") #'charrot-replace)

+end_src

Replacements can now be defined with charrot-define-abbrev (which also works interactively):

+begin_src elisp

(charrot-define-abbrev "->" " o") (charrot-define-abbrev "|->" "mapsto")

+end_src

Now typing C-; just after -> will turn it into the LaTeX command o; if the text before point is |-> then the replacement will be mapsto instead.

One can define rotating replacements with charrot-define-rotating:

+begin_src elisp

(charrot-define-rotating "..." "ldots" "cdots") (charrot-define-rotating "a" "alpha")

+end_src

Then, pressing C-; once after entring ... will turn it into ldots; pressing it once more will replace this with cdots; one more stroke of C-; turns back to the starting .... Likewise, invoking charrot-replace when point is past an a will turn it into alpha and then back into a.

If you have ever used X-Symbol with LaTeX, you already know (and perhaps miss) this feature. The file charrot-latex.el provides a list of replacements useful with TeX/LaTeX.

Caveats

The replacements table is global: you can't bind ^ to hat in LaTeX-mode and <sup></sup> in html-mode. (See TO-DO section.)

It is no error to define rotating replacements that cross; the latter definition partially overrides the former:

+begin_src elisp

(charrot-define-rotating "f*" "foo") (charrot-define-rotating "foo" "bar" "baz" "quux")

+end_src

Then calling charrot-replace turns f* into foo, but successive invocations will cycle through the strings bar, baz, and quux, without ever going back to f*.

TO-DO mode-local replacements ignore white space before point rotate replacements forwards and backwards? interactive definition of rotations? ** add "point placement" information? e.g., to replace ^ with hat{} and place point in between { and }