Re: Semicolons and the do..while statement

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Message-ID	<2708624.1MEYokBNaJ@PointedEars.de> (permalink)
From	Thomas 'PointedEars' Lahn <PointedEars@web.de>
Reply-To	Thomas 'PointedEars' Lahn <cljs@PointedEars.de>
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Subject	Re: Semicolons and the do..while statement
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John G Harris wrote:

> Thomas 'PointedEars' Lahn wrote:
>   <snip>
>>IOW,
>>
>>  do {} while (false) var x = 3;
>>
>>*is* equivalent to
>>
>>  do {} while (false); var x = 3;
>>
>>because `var' delimits a /VariableStatement/ and the parser is allowed, in
>>order to produce
>>
>   ...
>>
>>to insert the semicolon before the /VariableStatement/.  It's not a bug,
>>it's a feature, and a standards-compliant feature at that.
>   <snip>
> 
> This is not true. If you read ECMA 262 section 7.9.1 you will see that
> the gap between  (false)  and  var  does not match *any* of the
> situations where a semicolon can be inserted. The lack of a semicolon is
> therefore a syntax error.
> 
> Compilers that 'correct' programming errors are not being helpful. It
> can take a long time to track down an obscure bug caused by the compiler
> guessing wrong.

For crying out loud…

| 2 Conformance
| 
| […]
| A conforming implementation of ECMAScript is permitted to support program
| and regular expression syntax not described in this specification.  […]

This, if nothing else, is sufficient to make it standards-compliant.


PointedEars
-- 
Danny Goodman's books are out of date and teach practices that are
positively harmful for cross-browser scripting.
  -- Richard Cornford, cljs, <cife6q$253$1$8300dec7@news.demon.co.uk> (2004)

Thread

Re: Semicolons and the do..while statement BGB <cr88192@hotmail.com> - 2012-08-29 13:55 -0500
  Re: Semicolons and the do..while statement Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-08-29 22:20 +0200
    Re: Semicolons and the do..while statement BGB <cr88192@hotmail.com> - 2012-08-29 20:02 -0500
    Re: Semicolons and the do..while statement RobG <rgqld@iinet.net.au> - 2012-08-29 18:27 -0700
      Re: Semicolons and the do..while statement Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-08-30 12:37 +0200
    Re: Semicolons and the do..while statement John G Harris <john@nospam.demon.co.uk> - 2012-08-30 14:24 +0100
      Re: Semicolons and the do..while statement Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-08-30 15:59 +0200
        Re: Semicolons and the do..while statement John G Harris <john@nospam.demon.co.uk> - 2012-08-30 16:26 +0100
          Re: Semicolons and the do..while statement Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-08-30 17:47 +0200
            Re: Semicolons and the do..while statement John G Harris <john@nospam.demon.co.uk> - 2012-09-01 11:40 +0100
              Re: Semicolons and the do..while statement Dr J R Stockton <reply1235@merlyn.demon.co.uk.invalid> - 2012-09-02 19:54 +0100
          Re: Semicolons and the do..while statement BGB <cr88192@hotmail.com> - 2012-08-30 11:17 -0500
      Re: Semicolons and the do..while statement Gene Wirchenko <genew@ocis.net> - 2012-08-30 10:25 -0700
        Re: Semicolons and the do..while statement Dr J R Stockton <reply1235@merlyn.demon.co.uk.invalid> - 2012-08-31 23:20 +0100
          Re: Semicolons and the do..while statement Gene Wirchenko <genew@ocis.net> - 2012-08-31 16:03 -0700
  Re: Semicolons and the do..while statement Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-08-29 22:30 +0200

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