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Re: I don't get it

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From Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups comp.lang.javascript
Subject Re: I don't get it
Date Wed, 14 Apr 2021 01:32:36 +0100
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The Natural Philosopher <tnp@invalid.invalid> writes:

> On 13/04/2021 14:58, Ben Bacarisse wrote:
>>    The function is doing  exactly what you wrote.
>
> Not for at least two decades, and certainly not in JavaScript.
>
> The function is doing what the compiler and/or interpreter decided you
> *meant* by what you wrote.

It's a common mistake to think of code as implying more than it does.
This is particularly true of high-level languages like ECMAScript, but
it's also true of languages like C.  Assuming more than the language
guarantees has been the source of many bugs in C programs.

> Which is why you now have new keywords like 'volatile' to try and
> force it not to be clever with loop optimisations and Number() to
> ensure it actually does cast an unknown variable type to a number...

Hmm...  Your recent Number() example seems to be simply a case of your
not knowing what the language guarantees.

> Years ago I could look at a bit of C code and translate it into the
> actual assembler that the compiler would spit out. Today it produces
> nothing like that at all.
>
> So far I have always been impressed at how good it was at
> optimisation, but as I have said elsewhere, sometimes it gets it
> wrong.

I agree that all of this is contingent on the specification being clear
and there being no bugs in the language implementation.  But in JT's
case, I would be very surprised if the problem where a bug in the
implementation.  All beginners think they have found a compiler bug!

> And there are holes in the spec - areas that are 'indeterminate' and
> up to the whim of the compiler/interpreter and of course things like
> uninitialised memory.
>
> Then when you get to concurrent threads...

-- 
Ben.

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Thread

I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-08 03:32 -0700
  Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-08 03:37 -0700
    Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-08 04:26 -0700
      Re: I don't get it JJ <jj4public@gmail.com> - 2021-04-08 19:39 +0700
        Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-08 05:53 -0700
          Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-08 13:55 -0700
            Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-09 00:46 -0700
              Re: I don't get it The Natural Philosopher <tnp@invalid.invalid> - 2021-04-09 10:03 +0100
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-09 04:09 -0700
                Re: I don't get it "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2021-04-09 11:07 -0700
                Re: I don't get it The Natural Philosopher <tnp@invalid.invalid> - 2021-04-10 03:23 +0100
                Re: I don't get it "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2021-04-10 22:02 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-11 01:05 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-11 01:07 -0700
                Re: I don't get it The Natural Philosopher <tnp@invalid.invalid> - 2021-04-11 11:42 +0100
                Re: I don't get it John G Harris <niam@jghnorth.org.uk.invalid> - 2021-04-09 20:01 +0100
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-09 13:31 -0700
                Re: I don't get it The Natural Philosopher <tnp@invalid.invalid> - 2021-04-10 03:37 +0100
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-09 23:53 -0700
                Re: I don't get it John G Harris <niam@jghnorth.org.uk.invalid> - 2021-04-10 12:05 +0100
                Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-10 15:59 +0100
                Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-10 15:47 +0100
                Re: I don't get it The Natural Philosopher <tnp@invalid.invalid> - 2021-04-10 18:25 +0100
                Re: I don't get it Jon Ribbens <jon+usenet@unequivocal.eu> - 2021-04-10 17:29 +0000
                Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-10 19:08 +0100
                Re: I don't get it The Natural Philosopher <tnp@invalid.invalid> - 2021-04-11 11:41 +0100
                Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-11 14:33 +0100
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-12 02:39 -0700
                Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-12 11:21 +0100
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-12 10:19 -0700
                Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-12 21:20 +0100
                Re: I don't get it "sc...@sauyet.com" <scott@sauyet.com> - 2021-04-12 14:32 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-13 04:11 -0700
                Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-13 14:58 +0100
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-13 09:20 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-13 09:29 -0700
                Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-13 20:06 +0100
                Re: I don't get it "sc...@sauyet.com" <scott@sauyet.com> - 2021-04-13 15:09 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-14 01:15 -0700
                Re: I don't get it "sc...@sauyet.com" <scott@sauyet.com> - 2021-04-14 05:22 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-15 11:52 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-15 11:57 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-15 12:04 -0700
                Re: I don't get it Scott Sauyet <scott.sauyet@gmail.com> - 2021-04-15 19:29 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-20 14:12 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-20 14:47 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-20 23:35 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-21 01:08 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-21 01:24 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-21 01:29 -0700
                Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-13 09:32 -0700
                Re: I don't get it The Natural Philosopher <tnp@invalid.invalid> - 2021-04-13 21:59 +0100
                Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-14 01:32 +0100
                Re: I don't get it The Natural Philosopher <tnp@invalid.invalid> - 2021-04-14 09:08 +0100
                Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-14 10:06 +0100
                Re: I don't get it The Natural Philosopher <tnp@invalid.invalid> - 2021-04-14 10:59 +0100
                Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-14 14:05 +0100
                Re: I don't get it The Natural Philosopher <tnp@invalid.invalid> - 2021-04-14 16:32 +0100
                Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-14 23:53 +0100
                Re: I don't get it The Natural Philosopher <tnp@invalid.invalid> - 2021-04-15 13:56 +0100
                Re: I don't get it The Natural Philosopher <tnp@invalid.invalid> - 2021-04-12 11:20 +0100
        Re: I don't get it Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-04-08 15:21 +0100
          Re: I don't get it Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2021-04-09 16:50 +0200
  Re: I don't get it Man From a city with name Viljandi <he12457@hotmail.com> - 2021-04-08 10:44 -0700
  Re: I don't get it Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-04-10 00:01 -0700

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