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Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade!

Date 2012-03-01 16:46 -0800
From Westley Martínez <anikom15@gmail.com>
Subject Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade!
References <0078bbfb-5dfc-48fc-af1a-69de3cf15c3e@b1g2000yqb.googlegroups.com>
Newsgroups comp.lang.python
Message-ID <mailman.334.1330649220.3037.python-list@python.org> (permalink)

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First of all:

http://www.youtube.com/watch?v=z5jKMEB4hHE

On Wed, Feb 29, 2012 at 12:09:16AM -0800, Xah Lee wrote:
> Now, let me tell you what operator precedence is. First of all, let's
> limit ourselfs to discuss operators that are so-called binary
> operators, which, in our context, basically means single symbol
> operator that takes it's left and right side as operands. Now, each
> symbol have a “precedence”, or in other words, the set of operators
> has a order. (one easy way to think of this is that, suppose you have
> n symbols, then you give each a number, from 1 to n, as their order)
> So, when 2 symbols are placed side by side such as 「3 △ 6 ▲ 5」, the
> symbol with higher precedence wins. Another easy way to think of this
> is that each operator has a stickiness level. The higher its level, it
> more sticky it is.

You're absolutely correct.

> the problem with the perl explanations is that it's one misleading
> confusion ball. It isn't about “left/right associativity”. It isn't
> about “evaluates from left to right or right to left”. Worse, the word
> “associativity” is a math term that describe a property of algebra
> that has nothing to do with operator precedence, yet is easily
> confused with because it is a property about order of evaluation. (for
> example, the addition function is associative, meaning: 「(3+6)+5 =
> 3+(6+5)」.)

You're not getting it.

Math is a language.  Perl is a language.  They have different rules for
grammar.  In Perl, C, Python, Java, and pretty much all procedural-based
languages, operations are evaluated in two steps: the precedence /and/
the associativity.  Each level of precedence has its own associativity,
either left-to-right or right-to-left.  You can see this in table 2-1 in
The C Programming Language.  Whatever math does or what you think math
does has nothing to do with the way Perl evaluates expressions.

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New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Xah Lee <xahlee@gmail.com> - 2012-02-29 00:09 -0800
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Chiron <chiron613@gmail.com> - 2012-02-29 11:43 +0000
    Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-02-29 07:12 -0500
    Re: New Science Discovery: Perl Detracters Remain Idiots After A Decade! Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-02-29 23:06 -0500
      Re: New Science Discovery: Perl Detracters Remain Idiots After A Decade! Chiron <chiron613@gmail.com> - 2012-03-01 04:52 +0000
        Re: New Science Discovery: Perl Detracters Remain Idiots After A Decade! Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-03-01 10:07 -0500
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-02-29 13:08 +0100
    Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Xah Lee <xahlee@gmail.com> - 2012-02-29 16:02 -0800
      Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-01 12:00 +0100
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Xah Lee <xahlee@gmail.com> - 2012-03-02 05:12 -0800
          Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-02 15:15 +0100
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Rainer Weikusat <rweikusat@mssgmbh.com> - 2012-02-29 15:15 +0000
    Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-02-29 17:18 +0100
    Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-02-29 23:10 -0500
      Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Chiron <chiron613@gmail.com> - 2012-03-01 05:07 +0000
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-03-01 10:13 -0500
          Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Chiron <chiron613@gmail.com> - 2012-03-02 14:17 +0000
            Re: New Science Discovery: Perl Detractors Remain Idiots After A Decade! Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-03-02 10:53 -0500
              Re: New Science Discovery: Perl Detractors Remain Idiots After A Decade! Chiron <chiron613@gmail.com> - 2012-03-02 19:06 +0000
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-03-01 16:58 -0500
      Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Rainer Weikusat <rweikusat@mssgmbh.com> - 2012-03-01 14:40 +0000
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-03-01 16:11 -0500
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! namekuseijin <namekuseijin@gmail.com> - 2012-02-29 09:45 -0800
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Westley Martínez <anikom15@gmail.com> - 2012-03-01 16:46 -0800
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Chiron <chiron613@gmail.com> - 2012-03-02 07:27 +0000
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-03-12 11:27 +0000
    Re: New Science Discovery: Perl Detractors Remain Idiots After A Decade Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-03-12 08:40 -0400
      Re: New Science Discovery: Perl Detractors Remain Idiots After A Decade Raymond Wiker <raw@unknown-00-23-6c-8d-9e-26.lan> - 2012-03-12 19:20 +0100
    Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-12 14:05 +0100
      Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-03-12 19:00 +0000
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-12 21:27 +0100
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-13 12:00 +0100
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-13 12:03 +0100
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-03-12 16:20 -0400
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-13 17:41 +0100

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