-*-mode: Text; tab-width: 4; -*- EDWIN CHEAT SHEET (keep under your pillow) 6.090, IAP 2005 Reading Edwin key combinations: C-x Ctrl+x M-x Alt+x C-x, y Ctrl+x, release both, y C-M-x Ctrl+Alt+x Stuff You *Need* to Know: Starting Edwin Start Menu > MIT Scheme > Edwin Quitting Edwin C-x, C-c Opening a file C-x, C-f Closing a file (aka buffer) C-x, k Evaluate current expression C-x, C-e (expression ending just before insertion point) Evaluate entire buffer (works only on Scheme files!) M-o The Edwin Window and Scheme: When you start it, the Edwin window looks like a plain text editor. It has a large blank area for entering text, one black line at the bottom with some information displayed (the modeline), and a blank white line below that (the minibuffer). The text area is where the file you're viewing shows up. You can edit the file here, with the usual keys (up, down, page up, left... you get the idea). The modeline displays the name of the current buffer (file), your position in it, and the kind of file Edwin thinks it is (text, scheme code etc.). The minibuffer is where you interact with Edwin's commands. For example, when you press C-x, C-f to open a file, you enter the filename in the minibuffer. Edwin is more than just an editor, though. It also features a Scheme evaluator, to which it can send your code. So when you press C-x, C-e at the end of an expression, it gets evaluated by this evaluator (more on evaluators and evaluation in class). Try out the key combinations below to see what they do. Don't try to memorize them. Your finger muscles will learn them as time goes on :-) Inessential Edwin: Editing Marking/selecting text Go to one end of the block, press C-space, go to the other end. You won't see any visual indication of the selection. Cut C-w Copy M-w Paste C-y Cut from point to end of like C-k Multiple Windows and Buffers Switch buffer C-x, b Switch window C-x, o Split window vertically C-x, 2 Split window horizontally C-x, 3 Delete current split C-x, 0 Create new frame (window) C-x, 5, 2 Delete current frame C-x, 5, 0 Interactive Scheme: When you are in the buffer called *scheme*, everything you type goes directly to the evaluator, and the results are displayed below your expressions. When you make an error, the evaluator gives you a set of choices to help you debug your code. Usually, it is best to type (restart 1) at the next prompt to abort the current evaluation, so you can go back and examine your code to see what went wrong. For more advanced debugging tools, talk to an LA.