*start* 01134 00024 USt Date: 27 May 1981 9:53 am PDT (Wednesday) From: Mitchell.PA Subject: Editable Documents To: Horning cc: Mitchell Jim, I just thought I should record the main points of our conversation yesterday about editable documents, InterPress, etc. I am doing so at least partly because I think it would be a worthwhile policy to use Laurel heavily in this task in order to keep a complete record (e.g., for historical and patent reasons): We should use the same base language (abstract machine?) for InterDocuments as InterPress unless there is a really compelling reason to do otherwise. More strongly, Interpress is just one son of the original Press, which was to provide a common format for editable and printable documents; InterDocument is the other. A consequence of this is that there should exist documents which satisfy both the InterPress and the InterDocument standards, i.e., which are both editable and printable. Given the above, our real job in developing InterDocument is to understand very clearly just where it needs to be different than InterPress rather than designing it from scratch. JGM *start* 00431 00024 USt Date: 27 May 1981 10:17 am PDT (Wednesday) From: Horning.pa Subject: Re: Editable Documents In-reply-to: Your message of 27 May 1981 9:53 am PDT (Wednesday) To: Mitchell cc: Horning Jim, That puts it very well. What do you think about "InterDoc" rather than "InterDocument"? The InterDoc concept corresponding to a "master" should be a "script" (generalizes from manuscript, typescript, etc.). Jim H. *start* 01708 00024 USt Date: 29 May 1981 7:39 am PDT (Friday) From: Guibas.PA Subject: Some Doc Issues To: InterDoc↑.PA Reply-To: Guibas I think the establishment of the InterDoc DL is a fine idea. Here are some questions that the entire enterprise raises in my mind. 1. If an InterDoc document is processed by two different <editor-formatter>s (that is, transformed into an InterPress file), what do we want to be able to guarantee about the results? At what level do we expect the two documents (argh, it's so difficult not to overload this word - may be we should think of a different term!) to look the same? For example: There clearly must be a representation for "here is a paragraph of justified text using the current margins". But do we expect both InterDoc processors to compute the same line breaks? If so the the justification algorithm has to become part of the standard (and the hyphenation, and the pagination algorithms, too). 2. All <editor-formatter>s of any scope must rely on a model of document structure, perhaps based on some kind of a hierarchy, like book->chapter>-section->paragraph. (Think also of styles in BravoX, property lists in STAR, macros in TEX, etc.) How can the standard reflect all these different structures at once? Do we really expect to find a "universal" document structure so that any other structure can be embedded in it? Or will we punt and flatten out all structure? Is there any reasonable compromise between these extremes? Another way to ask the question is this: Do we really expect that when a document is transformed from a representation private to an <editor-formatter> to InterDoc format and back, that there will be no information loss? Leo *start* 01513 00024 USt Date: 29 May 1981 1:13 pm EDT (Friday) From: Lampson.PA Subject: Re: Some Doc Issues In-reply-to: Your message of 29 May 1981 7:39 am PDT (Friday) To: Guibas cc: InterDoc↑.PA Thoughts about your questions. 1. I think it is unrealistic to expect two Interdoc processors to implement the same line breaks agreement at that level will be too difficult to achieve, and also one of the reasons for handling a document rather than a master is the expectation that fonts, margins etc may change. On the othr hand, there are some areas in which details of layout are critical (notably in tables), and we must be careful to provide adequate control here. I am not too clear on what that might mean, however. 2. I don't think the structure will be "universal" at all. There will be room for reasonable men to disagree about whether the Interdoc structure is a good one, and I am sure it will exclude some currently popular ways of doing business. This is a bit of a problem with Interpress too, but much less so. For documents, I see no hope of avoiding a normative standard which will seriously conflict with some current methods. I certainly expect that implementations of the standard must have the same lossless property that is demanded of Interpress encodings. If they don't, what is the standard good for? By the way, I think Interdoc is a fine working name, but I find it much less satisfactory that Interpress, and I think we should search for a catchy replacement. Butler *start* 02048 00024 USt Date: 29 May 1981 11:39 am PDT (Friday) From: Horning.pa Subject: Re: Some Doc Issues In-reply-to: Your message of 29 May 1981 7:39 am PDT (Friday) To: Guibas cc: InterDoc↑ Leo, First, a technical note about Laurel 6: In a group "conversation," when Deliver asks you about a Reply-to: field, the appropriate answer is A (Answers to All); ESC will cause only you to see most of the replies. I'm pretty much in agreement with Butler's comments. It seems essential that a "conforming editor" must be able to translate one of its documents to a "script" in interchange format and back to internal format without losing any information. It also seems impractical to require that it be possible to interchange documents between independently-designed editors without losing information, or to require that different editors produce equivalent Interpress masters from the same script. I have no desire to standardize justification, line-breaking, hyphenation, etc. It seems to me that a script consists almost entirely of text and CONSTRAINTS on its presentation THAT HAVE BEEN IMPOSED BY THE USER. Default constraints supplied by particular editors needn't be represented. (This is the difference between automatically-supplied line breaks and user-formatted tables.) I think that the standard has to make provision for structures, but that it should not attempt to fix the hierarchy or to interpret it itself. I.e., at the interchange level, there is no reason to use different mechanisms to indicate different constraints such as this range of text is to be bold face, this range of text is to be treated as a second-level heading, this range of text is to be justified, this range of text is to be treated as a paragraph, or this range of text is to all appear on the same page. Perhaps another way of saying the same thing is that the standard should specify how attributes are to be attached to text, and interpretations for a standard set of attributes, but leave room for non-standard attributes. Jim H. *start* 00211 00024 USt Date: 29 May 1981 1:17 pm PDT (Friday) From: Warnock.PA Subject: InterDoc To: InterDoc↑ Are figures, drawings, charts etc. part of editable documents? (Let's look to the future folks). *start* 00547 00024 USt Date: 29 May 1981 1:29 pm PDT (Friday) From: Horning.pa Subject: Re: InterDoc In-reply-to: Warnock's message of 29 May 1981 1:17 pm PDT (Friday) To: Warnock cc: InterDoc↑ John, I guess that it never entered my mind that they wouldn't be (in the standard), although many editors don't currently support them, and they are likely to form a relatively small fraction of the documents interchanged in this decade (if for no other reason than the very different ways that different editors are likely to treat them). Jim H. *start* 00347 00024 USt Date: 29 May 1981 4:35 pm EDT (Friday) From: Lampson.PA Subject: Re: InterDoc In-reply-to: Warnock's message of 29 May 1981 1:17 pm PDT (Friday) To: Warnock cc: InterDoc↑ Of course figures, drawings, charts etc. are part of editable documents; surely that is not in the future. You'll have to be more adventurous, John. *start* 01564 00024 USt Date: 31 May 1981 12:27 pm PDT (Sunday) From: Mitchell.PA Subject: Re: Some Doc Issues In-reply-to: Lampson's message of 29 May 1981 1:13 pm EDT (Friday) To: Lampson cc: Guibas, InterDoc↑ This is a comment on your response to Leo's last question, vis. "Do we really expect that when a document is transformed from a representation private to an <editor-formatter> to InterDoc format and back, that there will be no information loss?" I think there is an important difference between InterPress and InterDoc when one considers going from the interchange encoding to a private encoding and back again. In the InterPress case, the master is not edited in this process, while in the InterDoc case, the conversion will most often be done just so that someone can edit the InterDoc "script". Imagine that one has a single-font, text-only, Interdoc-compatible editor, E, and edits some text of script S. Assume that E converts S into a private encoding P(S), then lets a user edit some text, and finally converts P(S') to S'. I would certainly expect that the parts of S that E cannot edit, such as illustrations, should survive the two conversions intact and unchanged. I am not so sure as to what can be said about the edited portions of S'. For example if one edited a few characters in a Helvetica14 paragraph, would only those characters appear in E's single font in S', would the entire paragraph be in E's font, or would none of the paragraph appear in E's font (because it is a paragraph property rather than a textual one)? JGM