Extended Cursor Movement in terminal emulator (CHA and others)

Question

Is there a way to get the Emacs terminal emulator to support cursor movement escape sequences beyond its vt100 features? A specific example is CHA (Cursor-Character-Absolute), e.g. ESC[0G should move the cursor to column 0. CHA and a few other sequences were added as part of ISO-6429 (ECMA-48).

Try this rudimentary test in eterm and another terminal emulator:

printf "hello\033[0Gworld\n"

In eterm (M-x term or M-x multi-term) you will see:

helloworld

In Terminal.app I see:

world

For a full featured test check out vttest (brew install test for me).

Answer 1

No, it doesn't look that it's possible without some hacking. The function term-handle-ansi-escape in term.el doesn't have a case for ESC [ G.

Answer 2

Given the pointer to term-handle-ansi-escape by @jch I was able to add support for CHA as follows:

(defun toolbear:term-handle-more-ansi-escapes (proc char)
  "Handle additional ansi escapes."
  (cond
   ;; \E[nG - Cursor Horizontal Absolute, e.g. move cursor to column n
   ((eq char ?G)
    (let ((col (min term-width (max 0 term-terminal-parameter))))
      (term-move-columns (- col (term-current-column)))))
   (t)))
(advice-add 'term-handle-ansi-escape :before #'toolbear:term-handle-more-ansi-escapes)