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Re: sweet-expressions are not homoiconic
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John Cowan writes:
> 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.
Well, it did take a considerable time (measured in generations) for
the use of whitespace as a word separator to become standard. But there
was an obvious motivating advantage in that case: separated-word texts are
significantly less ambiguous. No such advantage accrues to
> > 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.
Yes, and we see how well that works out when the hierarchies are as
deeply nested as those in LISP-like languages are.
The other common case of the use of indentation to indicate
grouping is legislative bills, which I would hesitate to cite as exemplars
of readability and homoiconicity.
It's not a persuasive argument to say that Scheme programs could be
made just as readable as Congressional legislation and the wordier kinds of
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