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From: matt@bacchus.esa.oz (Matt Atterbury)
Newsgroups: comp.sources.wanted,aus.wanted,comp.text
Subject: Re: Hierarchical structure -> graphical representation (c.f. GPIC/GTROFF)
Message-ID: <MATT.90Sep24114614@percy.bacchus.esa.oz>
Date: 24 Sep 90 01:46:14 GMT
References: <1990Sep22.032404.20089@brolga.cc.uq.oz.au>
Sender: matt@bacchus.esa.oz
Distribution: comp
Organization: Expert Solutions Australia.
Lines: 54
In-reply-to: exnirad@brolga.cc.uq.oz.au's message of 22 Sep 90 03:24:04 GMT

In article <1990Sep22.032404.20089@brolga.cc.uq.oz.au> exnirad@brolga.cc.uq.oz.au (Nirad Sharma) writes:

   I wish to translate a c representation of a hierarchical structure
   i.e. struct info {
           ...attributes...
           struct info  *children, *sibling
           }

   into PIC statements that will generate visually balanced trees
   i.e.           o
                 / \
                o   o
               /  |  \
              o   o   o


    I have a program that takes a file of format:

        tree ::= node
        node ::= name subtree
        subtree ::= <nothing> | '(' { node } ')'

    (well, one a bit more specific than that, but you get the idea).
    It doesn't handle digraphs, just trees (what is the `|` in your
    pic?). It doesn't produce PIC output, just ASCII chars.

    eg.
        A                                   A
        (                                  / \
            B                             /   \
            C                            B     C
            (               ->                / \
                D                            /   \
                E                           D     E
            )
        )

    It is for drawing JSD entity-action diagrams, but it should be
    reasonably easy to modify. It has a number of stages:
        parse input file to build internal representation
        layout text for each node using a heuristic
        position each node within the whole tree - (x,y) of T/L corners
        draw tree (using + - | ' ' for line drawing and positioning).
    I would expect that it wouldn't be too hard to hack for your
    purpose. The hard part is positioning each node. I believe my
    algorithm is correct (it has worked fine so far). Interested? I
    have posted in case anyone else is also interested, since this is
    a classical example of something that shouldn't have to be
    re-invented by everyone!
--
-------------------------------------------------------------------------------
Matt Atterbury [matt@bacchus.esa.oz]      Expert Solutions Australia, Melbourne
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