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JSLint Unexpected Warning

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  JSLint Unexpected Warning emfril@gmail.com - 2019-04-25 01:28 -0700
    Re: JSLint Unexpected Warning "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2019-04-25 04:33 -0700
      Re: JSLint Unexpected Warning Julio Di Egidio <julio@diegidio.name> - 2019-05-16 20:13 -0700
        Re: JSLint Unexpected Warning "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2019-05-18 10:59 -0700
    Re: JSLint Unexpected Warning "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2019-04-25 17:43 +0200
      Re: JSLint Unexpected Warning Gene Wirchenko <genew@telus.net> - 2019-04-25 16:43 -0700
        Re: JSLint Unexpected Warning "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2019-04-26 13:30 +0200
          Re: JSLint Unexpected Warning Gene Wirchenko <genew@telus.net> - 2019-04-29 11:04 -0700
            Re: JSLint Unexpected Warning "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2019-04-30 00:06 +0200
              Re: JSLint Unexpected Warning Gene Wirchenko <genew@telus.net> - 2019-04-30 21:15 -0700
    Re: JSLint Unexpected Warning emf <emfril@gmail.com> - 2019-05-16 22:31 -0400
      Re: JSLint Unexpected Warning Julio Di Egidio <julio@diegidio.name> - 2019-05-16 20:08 -0700
      Re: JSLint Unexpected Warning Julio Di Egidio <julio@diegidio.name> - 2019-05-16 20:38 -0700
      Re: JSLint Unexpected Warning Jon Ribbens <jon+usenet@unequivocal.eu> - 2019-05-17 12:17 +0000

#36409 — JSLint Unexpected Warning

JSLint says:

Unexpected '==='.
        if (((a > b) === (bc > ca)) && ((b > c) === (ca > ab))
0.48
Unexpected '==='.
in this (and others):

if (((a > b) === (bc > ca)) && ((b > c) === (ca > ab))
  && ((c > a) === (ab > bc)) && ((a === b) === (bc === ca))
  && ((b === c) === (ca === ab)) && ((c === a) !== (ab === bc))) {
    return false;
} else {
    return true;
}

Why?

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#36412

On Thursday, April 25, 2019 at 3:28:22 AM UTC-5, emf...@gmail.com wrote:
> JSLint says:
> 
> Unexpected '==='.
>         if (((a > b) === (bc > ca)) && ((b > c) === (ca > ab))
> 0.48
> Unexpected '==='.
> in this (and others):
> 
> if (((a > b) === (bc > ca)) && ((b > c) === (ca > ab))
>   && ((c > a) === (ab > bc)) && ((a === b) === (bc === ca))
>   && ((b === c) === (ca === ab)) && ((c === a) !== (ab === bc))) {
>     return false;
> } else {
>     return true;
> }
> 
> Why?

Try a different linter:

https://eslint.org/demo/#eyJ0ZXh0IjoiZnVuY3Rpb24gZm9vKGEsIGIsIGMsIGFiLCBiYywgY2EpIHtcclxuICAgIGlmICgoKGEgPiBiKSA9PT0gKGJjID4gY2EpKSAmJiAoKGIgPiBjKSA9PT0gKGNhID4gYWIpKSAmJlxyXG4gICAgICAgICgoYyA+IGEpID09PSAoYWIgPiBiYykpICYmICgoYSA9PT0gYikgPT09IChiYyA9PT0gY2EpKSAmJlxyXG4gICAgICAgICgoYiA9PT0gYykgPT09IChjYSA9PT0gYWIpKSAmJiAoKGMgPT09IGEpICE9PSAoYWIgPT09IGJjKSlcclxuXHQpIHtcclxuICAgICAgICByZXR1cm4gZmFsc2U7XHJcblx0fSBlbHNlIHtcclxuICAgICAgICByZXR1cm4gdHJ1ZTtcclxuXHR9XHJcbn1cclxuXHJcbmZvbyh0cnVlLCBmYWxzZSwgZmFsc2UsIHRydWUsIGZhbHNlLCB0cnVlKSIsIm9wdGlvbnMiOnsicGFyc2VyT3B0aW9ucyI6eyJlY21hVmVyc2lvbiI6NSwic291cmNlVHlwZSI6InNjcmlwdCIsImVjbWFGZWF0dXJlcyI6e319LCJydWxlcyI6eyJjb25zdHJ1Y3Rvci1zdXBlciI6MiwiZm9yLWRpcmVjdGlvbiI6MiwiZ2V0dGVyLXJldHVybiI6Miwibm8tY2FzZS1kZWNsYXJhdGlvbnMiOjIsIm5vLWNsYXNzLWFzc2lnbiI6Miwibm8tY29tcGFyZS1uZWctemVybyI6Miwibm8tY29uZC1hc3NpZ24iOjIsIm5vLWNvbnNvbGUiOjIsIm5vLWNvbnN0LWFzc2lnbiI6Miwibm8tY29uc3RhbnQtY29uZGl0aW9uIjoyLCJuby1jb250cm9sLXJlZ2V4IjoyLCJuby1kZWJ1Z2dlciI6Miwibm8tZGVsZXRlLXZhciI6Miwibm8tZHVwZS1hcmdzIjoyLCJuby1kdXBlLWNsYXNzLW1lbWJlcnMiOjIsIm5vLWR1cGUta2V5cyI6Miwibm8tZHVwbGljYXRlLWNhc2UiOjIsIm5vLWVtcHR5IjoyLCJuby1lbXB0eS1jaGFyYWN0ZXItY2xhc3MiOjIsIm5vLWVtcHR5LXBhdHRlcm4iOjIsIm5vLWV4LWFzc2lnbiI6Miwibm8tZXh0cmEtYm9vbGVhbi1jYXN0IjoyLCJuby1leHRyYS1zZW1pIjoyLCJuby1mYWxsdGhyb3VnaCI6Miwibm8tZnVuYy1hc3NpZ24iOjIsIm5vLWdsb2JhbC1hc3NpZ24iOjIsIm5vLWlubmVyLWRlY2xhcmF0aW9ucyI6Miwibm8taW52YWxpZC1yZWdleHAiOjIsIm5vLWlycmVndWxhci13aGl0ZXNwYWNlIjoyLCJuby1taXhlZC1zcGFjZXMtYW5kLXRhYnMiOjIsIm5vLW5ldy1zeW1ib2wiOjIsIm5vLW9iai1jYWxscyI6Miwibm8tb2N0YWwiOjIsIm5vLXJlZGVjbGFyZSI6Miwibm8tcmVnZXgtc3BhY2VzIjoyLCJuby1zZWxmLWFzc2lnbiI6Miwibm8tc3BhcnNlLWFycmF5cyI6Miwibm8tdGhpcy1iZWZvcmUtc3VwZXIiOjIsIm5vLXVuZGVmIjoyLCJuby11bmV4cGVjdGVkLW11bHRpbGluZSI6Miwibm8tdW5yZWFjaGFibGUiOjIsIm5vLXVuc2FmZS1maW5hbGx5IjoyLCJuby11bnNhZmUtbmVnYXRpb24iOjIsIm5vLXVudXNlZC1sYWJlbHMiOjIsIm5vLXVudXNlZC12YXJzIjoyLCJuby11c2VsZXNzLWVzY2FwZSI6MiwicmVxdWlyZS15aWVsZCI6MiwidXNlLWlzbmFuIjoyLCJ2YWxpZC10eXBlb2YiOjJ9LCJlbnYiOnt9fX0=

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#36619

On Thursday, 25 April 2019 13:34:02 UTC+2, Michael Haufe (TNO)  wrote:

> Try a different linter:

Bad advice.  Rather, find a decent linter then stick to it and rather
customise your configuration.

Following industry-wide practices is important,so do not configure your
linting as a dick: OTOH, it's a mistake to think that here there is, or
even that there should be, a fit for all.  Conventions are team-wise...

Julio

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#36622

Julio Di Egidio wrote:
> [nothing significant]

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#36414

emfril@gmail.com wrote on 25 Apr 2019 in comp.lang.javascript:

> JSLint says:
> 
> Unexpected '==='.
>         if (((a > b) === (bc > ca)) && ((b > c) === (ca > ab))
> 0.48
> Unexpected '==='.
> in this (and others):

That is to be expected when you make an error.

Hint: count your ('s and )'s.

> if (((a > b) === (bc > ca)) && ((b > c) === (ca > ab))
>   && ((c > a) === (ab > bc)) && ((a === b) === (bc === ca))
>   && ((b === c) === (ca === ab)) && ((c === a) !== (ab === bc))) {
>     return false;
>} else {
>     return true;
>}
> 
> Why?

Same thing

================================

btw:

if (myBoolean)
    return false
else
    return true;

is a unnecesarily difficult way of writing:

return ! myBoolean;

-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

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#36421

On Thu, 25 Apr 2019 17:43:29 +0200, "Evertjan."
<exxjxw.hannivoort@inter.nl.net> wrote:

>emfril@gmail.com wrote on 25 Apr 2019 in comp.lang.javascript:
>
>> JSLint says:
>> 
>> Unexpected '==='.
>>         if (((a > b) === (bc > ca)) && ((b > c) === (ca > ab))
>> 0.48
>> Unexpected '==='.
>> in this (and others):
>
>That is to be expected when you make an error.
>
>Hint: count your ('s and )'s.
>
>> if (((a > b) === (bc > ca)) && ((b > c) === (ca > ab))
>>   && ((c > a) === (ab > bc)) && ((a === b) === (bc === ca))
>>   && ((b === c) === (ca === ab)) && ((c === a) !== (ab === bc))) {
>>     return false;
>>} else {
>>     return true;
>>}
>> 
>> Why?
>
>Same thing

     The parens look balanced with this second one, but it is bad
code, because it is too complicated.

>================================
>
>btw:
>
>if (myBoolean)
>    return false
>else
>    return true;
>
>is a unnecesarily difficult way of writing:
>
>return ! myBoolean;

     Quite.  You might need parens around the boolean if it is an
expression.

Sincerely,

Gene Wirchenko

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#36430

Gene Wirchenko <genew@telus.net> wrote on 26 Apr 2019 in 
comp.lang.javascript:

>>btw:
>>
>>if (myBoolean)
>>    return false
>>else
>>    return true;
>>
>>is a unnecesarily difficult way of writing:
>>
>>return ! myBoolean;
> 
>      Quite.  You might need parens around the boolean if it is an
> expression.

Why? 



-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

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#36486

On Fri, 26 Apr 2019 13:30:50 +0200, "Evertjan."
<exxjxw.hannivoort@inter.nl.net> wrote:

>Gene Wirchenko <genew@telus.net> wrote on 26 Apr 2019 in 
>comp.lang.javascript:
>
>>>btw:
>>>
>>>if (myBoolean)
>>>    return false
>>>else
>>>    return true;
>>>
>>>is a unnecesarily difficult way of writing:
>>>
>>>return ! myBoolean;
>> 
>>      Quite.  You might need parens around the boolean if it is an
>> expression.
>
>Why? 

     If the expression has more than one part, the negation will not
give the right result.  Suppose the boolean is
          IsCust && HasCredit
The negation is not
          !IsCust && HasCredit
but
          !(IsCust && HasCredit)

Sincerely,

Gene Wirchenko

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#36490

Gene Wirchenko <genew@telus.net> wrote on 29 Apr 2019 in 
comp.lang.javascript:

>>>>return ! myBoolean;
>>> 
>>>      Quite.  You might need parens around the boolean if it is an
>>> expression.
>>
>>Why? 
> 
>      If the expression has more than one part, the negation will not
> give the right result.  Suppose the boolean is
>           IsCust && HasCredit
> The negation is not
>           !IsCust && HasCredit
> but
>           !(IsCust && HasCredit)

True!

I was under the impression that you meant this expression:

return (! myBoolean);

because THAT was my expression, 
because myBoolean is imho not an expression, 
but just a value.




-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

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#36513

On Tue, 30 Apr 2019 00:06:02 +0200, "Evertjan."
<exxjxw.hannivoort@inter.nl.net> wrote:

>Gene Wirchenko <genew@telus.net> wrote on 29 Apr 2019 in 
>comp.lang.javascript:
>
>>>>>return ! myBoolean;
>>>> 
>>>>      Quite.  You might need parens around the boolean if it is an
>>>> expression.
>>>
>>>Why? 
>> 
>>      If the expression has more than one part, the negation will not
>> give the right result.  Suppose the boolean is
>>           IsCust && HasCredit
>> The negation is not
>>           !IsCust && HasCredit
>> but
>>           !(IsCust && HasCredit)
>
>True!
>
>I was under the impression that you meant this expression:
>
>return (! myBoolean);
>
>because THAT was my expression, 
>because myBoolean is imho not an expression, 
>but just a value.

     I thought that might be the case.  I just wanted to warn about
the more general issue.  Some people are not so familiar with complex
boolean expressions.  I get hung up on some messy ones on occasion
myself.

     Keep pushing out good advice.

Sincerely,

Gene Wirchenko

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#36616

On 2019-04-25 4:28, emfril@gmail.com wrote:
> JSLint says:
> 
> Unexpected '==='.
>          if (((a > b) === (bc > ca)) && ((b > c) === (ca > ab))
> 0.48
> Unexpected '==='.
> in this (and others):
> 
> if (((a > b) === (bc > ca)) && ((b > c) === (ca > ab))
>    && ((c > a) === (ab > bc)) && ((a === b) === (bc === ca))
>    && ((b === c) === (ca === ab)) && ((c === a) !== (ab === bc))) {
>      return false;
> } else {
>      return true;
> }
> 
> Why?

Thanks for all the replies. When, however, I submit to JSLint just this

function isValid() {
     if ((a > b) === (bc > ca)) {
         return false;
     } else {
         return true;
     }
}

it still says:

Unexpected '==='.
     if ((a > b) === (bc > ca)) {

It accepts, however, as correct this:

function isValid() {
     var agb = (a > b);
     var bcgca = (bc > ca);
     if (agb === bcgca) {
         return false;
     } else {
         return true;
     }
}

It seems JSLint does not like to perform (boolean) operations within the 
condition except for the main one.

I feel like JSLint is a moving target. Every time I consult it, there is 
always something new it doesn't like. So far I've been following its 
directions, but I do wish I were sure it's heading in the right direction...

Eustace

-- 
Spherical Triangle Calculator
http://emf.neocities.org/tr/spherical.html

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

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#36618

On Friday, 17 May 2019 04:31:00 UTC+2, emf  wrote:

> I feel like JSLint is a moving target.

Linters are tools to help enforcing conventions and catching some
kinds of bugs, period.

In particular:
Linting is supportive [can I say this in English?], not normative.
Linting is configurable, i.e. not meant to be a "fixed target".
Linting won't teach you how to code properly, less of all how to
structure your code.

Use linters, just use them cum grano salis.

HTH,

Julio

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#36620

On Friday, 17 May 2019 04:31:00 UTC+2, emf  wrote:
> On 2019-04-25 4:28, emfril@gmail.com wrote:
> > JSLint says:
<snip>
> function isValid() {
>      if ((a > b) === (bc > ca)) {
>          return false;
>      } else {
>          return true;
>      }
> }
> 
> it still says:
> 
> Unexpected '==='.
>      if ((a > b) === (bc > ca)) {

Indeed, that's at least ugly.  :)

First, that boils down to:

  function isValid() {
    return !(a > b === bc > ca);
  }

And now note that you are "reifying" the result of the two comparisons
instead of just writing a plain boolean expression, which would be:

  function isValid() {
    return !(a > b && bc > ca || !(a > b) && !(bc > ca));
  }

Now, granted, I personally would not object to your using ===,
certainly not in that case, also considering that in JS there
is no actual reification going on (IIANM).  OTOH, that's certainly
not the only linting rule I would usually relax re the default
set, which is mostly tailored to the rookie and always to the
detriment of actual expert programming, industry-wide...

HTH, anyway my 2c.

Julio

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#36621

On 2019-05-17, emf <emfril@gmail.com> wrote:
> It seems JSLint does not like to perform (boolean) operations within the 
> condition except for the main one.
>
> I feel like JSLint is a moving target. Every time I consult it, there is 
> always something new it doesn't like. So far I've been following its 
> directions, but I do wish I were sure it's heading in the right direction...

Ditch JSLint, install Standard, job done :-) https://standardjs.com/

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