% -*-LaTeX-*- % TECOMINI.LTX.11, 28-May-86 16:33:45, Edit by BEEBE % This is part of TECO.LTX \ETECO{} is accessible from inside \EMACS{} in a small buffer called the {\em minibuffer}, which is displayed when the function \EC{\CARET{}R Minibuffer}, normally bound to the key M-Altmode, is invoked. It appears as a small four-line window at the top of the screen, and its contents are saved on the command ring, which itself is stored in Q-vector \TX{.N}. The minibuffer can be edited as normal text, except that \A{ESC} is made a self-inserting character, rather than bound to its usual \EC{\CARET{}R Prefix Meta} function. Two features of the \EMACS{} minibuffer are annoying---its initial size is set at four lines, which is often too small, and it does not have a default file attached to it like a normal edit buffer, so saving its contents requires a few more keystrokes than would otherwise be necessary. In this implementation of \TECO{} on top of \EPSILON{}, the minibuffer is a normal buffer named \T{*MINIBUFFER*}, and it can have a filename attached to it if the code is to be saved. The minibuffer can be selected by any of the standard buffer switching commands, but as in \EMACS{}, the command \EC{minibuffer} is bound to M-Altmode (Alt-\A{ESC} in \EPSILON{} terminology, since the \IBMPC{} keyboard has a meta-key labeled {\em ALT}\/).\index{ALT key} Instead of doing a buffer switch, this enters a recursive editing mode, with the minibuffer replacing the current window. When \EC{exit-level}, bound to \T{C-X C-Z}, is run, the recursive editing level is exited, and the original buffer reappears in the window. For debugging convenience, if the last two characters in the minibuffer are \A{ESC}'s, when \EC{minibuffer} exits, it runs \EC{step-minibuffer} which uses the \TECO{} debugger described in the next section to examine the program execution. \TECO{} editing mode is automatically selected when the minibuffer is the current buffer, or whenever a file with extension \T{.TEC} is visited. The only key binding change it makes is that \A{ESC} is bound to \EC{normal-character} instead of \EC{alt-prefix}. Since the {\em ALT} key is still bound to the latter, no inconvenience is incurred. Once a \TECO{} program in the minibuffer is ready for execution, you select the buffer which is to be the \TECO{} edit buffer, then execute the program with \EC{execute-minibuffer}, normally bound to \T{C-X} \A{ESC}. The \TECO{} interpreter checks for a user abort before executing each command, so a run-away program can always be stopped by the \EC{abort} command bound to \T{C-G}.