Too much code - slicing

[Seebs]

On 2010-09-19, Steven D'Aprano <steve at REMOVE-THIS-cybersource.com.au> wrote:
> I'm not entirely sure I agree with you here... you can't ignore syntax in 
> order to understand the meaning of code.

No, but the syntax should be invisible.  When I read English, I don't have
to think about nouns and verbs and such unless something is very badly
written.  The syntax is handled automatically at a lower level without
conscious intervention, as it should be.  Calling my conscious attention
to it is disruptive.

> The term "syntax highlighting" for what editors I've seen do is actually 
> misleading -- they don't highlight *syntax*, they try to highlight 
> *semantics*.

I've never seen this.  I've seen things highlight comments and keywords
and operators and constants and identifiers differently.

> When your editor highlights the function len() in the 
> expression "x = len(y) + spam(z)" but not the function spam(), you know 
> it has nothing to do with syntax. len() is singled out because of its 
> semantics, namely the fact that it's a built-in.

Eww.  (I had not yet gotten to the point of finding out that whether
something was "built-in" or not substantially affected its semantics.)

> In English, the meaning of the some sentences do benefit by syntax 
> highlighting, and in fact that's partly what punctuation is for: English 
> partly uses punctuation marks as tags to break the sentence structure 
> into sub-sentences, clauses and terms (particularly when the sentence 
> would otherwise be ambiguous).

Punctuation is very different from highlighting, IMHO.  That said, I
find punctuation very effective at being small and discrete, clearly not
words, and easy to pick out.  Color cues are not nearly as good at
being inobtrusive but automatically parsed.

> "Woman shoots man with crossbow"

> Was it the man armed with a crossbow, or the woman? If we could somehow group the 
> clause "with crossbow" with "woman" or "man" by something *other* than 
> proximity, we could remove the ambiguity.

Yes.  But syntax highlighting won't help you here -- at least, I've never
yet seen any editor that showed precedence relations or anything similar
in its coloring.

> Bringing it back to Python, that's why punctuation like : are useful. 
> They're syntax highlighting.

I don't think they are, though.  I think punctuation is fundamentally
different in intent and purpose from colorizing things based on whether
they're, say, constants or identifiers or comments or keywords.  The
punctuation is *itself* part of the syntax -- it's not being highlighted.

Syntax highlighting is putting all the punctuation in green so you know
it's punctuation.

-s
-- 
Copyright 2010, all wrongs reversed.  Peter Seebach / usenet-nospam at seebs.net
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