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Re: sweet-expressions are not homoiconic

This page is part of the web mail archives of SRFI 110 from before July 7th, 2015. The new archives for SRFI 110 contain all messages, not just those from before July 7th, 2015.

John David Stone scripsit:

> From the beginning, there was an obvious impediment to the use of
> sweet-expressions:  Readers who are accustomed to alphabetic writing
> systems in which whitespace is almost invariably used as a word
> separator, a paragraph separator, a decorative typographical element,
> or for page layout simply don't respond psychologically to whitespace
> characters as they do to visible characters such as parentheses.


> Whitespace characters don't look like grouping symbols, as
> parentheses, brackets, braces, or oriented quotation marks do, because
> they don't have appropriate shapes and don't come in pairs.  Moreover,
> they don't visibly nest, so it is unnatural to use them to represent
> recursively defined syntactic structures.

Au contraire.  It is so natural than even suits use nested indentation
to show hierarchy in their PowerPoints.

The difficulties arise when things *aren't* just represented
hierarchically, when people start to want shortcuts that are more
compact than pure hierarchy.  The great advantage of classical Lisp
indentation is that it saves vertical whitespace.  Attempts to reproduce
this virtue within the different context of indentation are where the
epicycles come in.

My confusion is rapidly waxing          John Cowan
For XML Schema's too taxing:            cowan@xxxxxxxx
    I'd use DTDs                        http://www.ccil.org/~cowan
    If they had local trees --
I think I best switch to RELAX NG.