NonGNU ELPA - teco

TECO.EL

TECO is an ancient text editor written in the days before most of you reading this were born. It supported macros of editing commands as an extension mechanism. The original version of EMACS was written in TECO by loading macros that provided the EMACS functionality and then saving the memory image of the combined TECO command interpreter and macros as a new program ("dumping" an EMACS).

As an editor, the TECO commands (the operators of the macro language) were terse and powerful. From within EMACS, one could open a 'minibuffer' by typing ESC ESC and then enter a TECO program which would be run (by typing ESC ESC again) to modify the underlying EMACS buffer. E.g. if you wanted to add a new column containing the string 'EMPTY' between the second and third columns of a CSV file, you could execute the TECO program

<.-z; 2fwl i,EMPTY$ l>

• "<" loop body ">"
• ".-z" (point - end of buffer)
• ";" end loop test (if prefix arg ".-z" is >= 0)
• "2fwl" is really three things: "2" => repeat count, "fw" => bounds of a word, "l" => move forward
• "iSTRING-TO-INSERT$" (where $ is actually ESC)
• "l" (with no args) move to the beginning of the next line

While this is easily done with a keyboard macro, the TECO language offers more functionality and is often quicker to use if you're willing to pay the cost of learning how to use it. Personally, I'm addicted to clearing a buffer by executing the TECO program hk.

Dale Worley (worley@alum.mit.edu) implemented this TECO interpreter in Elisp. It was originally available from the old EMACS LCD archive and was still kicking around the EmacsWiki. Since I still use it, I created this package to make it available from the modern Emacs package system.

https://en.wikipedia.org/wiki/TECO_(text_editor)

https://emacswiki.org/emacs/TecoInterpreterInElisp>

https://www.emacswiki.org/emacs/teco.el

https://github.com/mtk/teco.git