Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!quintus!pds From: pds@quintus.UUCP (Peter Schachte) Newsgroups: comp.lang.lisp Subject: Re: lisp environments (Structure vs. text editors) Message-ID: <466@cresswell.quintus.UUCP> Date: 14 Dec 87 20:35:34 GMT References: <487@PT.CS.CMU.EDU> <460@cresswell.quintus.UUCP> <499@PT.CS.CMU.EDU> Organization: Quintus Computer Systems, Mountain View, CA Lines: 51 << I tried to post this to comp.editors, but my news system didn't want to >> In article <499@PT.CS.CMU.EDU>, ralphw@IUS2.CS.CMU.EDU (Ralph Hyre) writes: > In article <460@cresswell.quintus.UUCP> pds@quintus.UUCP (Peter Schachte) writes: > >Text editors CANNOT simulate structure editors. They can do a rather > >feeble job of it. Text editors fall down when context information is > >needed in order to decide what to do... > > I disagree - a PROGRAMMABLE text editor can do anything you want. This is > because it's programmable. Whether you're happy with the performance or a > particular implementation is a separate, but important issue. When performance gets bad enough, it BECOMES the central issue. If Emacs spends several seconds determining context for EACH KEYSTROKE, it becomes unusable. > > >...For example: a structure editor can supply different commands, different > >facilities, for editing comments and code. > Seems like there's the potential here for moby modefulness. I can't see > why I would want different commands when I edit code compared with comments. Don't you switch Emacs to text mode to edit block comments? Line wrap is so useful there. Better yet, why not have the paragraphs auto-filled and auto justified while you type, like a word processor? Make your comments look nice. Use boldface, italics, large headings, etc. Why not? Just because your tools won't let you? > ... it's just a matter of > whether you want to have a fixed view of editing or a completely > open (and programmable) one. No, it's a matter of what information you want available to your programs. There's nothing to say that a structure editor can't be programmable. A programmable text editor has access to the text of a program or document, and must parse it in order to determine context. A structure editor has access to the structure of program or document, and must unparse (print) it in order to keep the screen up-to-date. Printing is usually easier than parsing. > > [disclaimer: I've never used a 'structure editor' except for the MacPascal > editor, it kept getting in the way. I have used some EMACS packages (like > Scheme mode) which meet my needs without taking away functionality.] Sometime, try SEdit, the new Interlisp structure editor. It still has some weaknesses, but you might be surprised at how much it can look like a text editor, and how much advantage it takes of having the structure around. You might be pleasantly surprised. -- -Peter Schachte pds@quintus.uucp ...!sun!quintus!pds