Le 30 janv. 2013 à 18:00, Andrea Giammarchi <[email protected]> a
écrit :
> let me rephrase ...
>
> putting `with(this){` before any build process/inlined library and `}` at the
> end of all concatenated files **nothing** is strict anymore ^_^
>
> function isStrict() {"use strict";
> return this;
> }
>
> isStrict(); // undefined
>
> now, wraping the whole thing inside a with statement
>
> with(this){
> function isStrict() {"use strict";
> return this;
> }
> alert(isStrict()); // global object
> }
Presumably some weirdness between "with" statement mixed with function
declaration. You should test specifically the strictness, not the this-binding:
with(this){
function test() {
"use strict"
return (function() { return this === void 0 })()
}
alert(test()); // true
}
The test function is manifestly in strict mode regardless of its this-binding.
...
!! But wait, I think I understand what's happening:
var obj = {
returnThis: function() { "use strict"; return this }
, toString: function() { return 'I am "obj"' }
}
var otherReturnThis = function() { "use strict"; return this }
with(obj){
alert(returnThis()); // 'I am "obj"'
alert(otherReturnThis()); // undefined
}
Here, "returnThis()" is strictly equivalent to "obj.returnThis()", including
the this-binding, while "otherReturnThis()" use "undefined" as target object
In your example, when you say "isStrict()", it is interpreted as
"this.isStrict()", since "isStrict" is a property of "this" and "this" is the
argument of the "with" statement. (You're still with me?) Nothing to do with
strict mode
Ok, you convinced me that the semantic of the "with" statement is *really*
weird, but not that you can disable strict mode.
—Claude
>
> forget the Function hack, there is no library able to ensure itself to be
> executed in strict mode.
> Using the width statement around any code makes it not strict.
>
> Thoughts ?
>
>
>
>
>
>
>
>
>
> On Wed, Jan 30, 2013 at 8:19 AM, Brandon Benvie <[email protected]>
> wrote:
> Correction, the use strict directive needs to appear as the first statement
> (ExpressionStatement) that's not an EmptyStatement and not a
> FunctionDeclaration. Anything else will cause the directive to be ignored.
>
>
> On Wed, Jan 30, 2013 at 11:15 AM, Brandon Benvie <[email protected]>
> wrote:
> To enable strict mode, the "use strict" expression must come as the first
> non-statement of a script or function body. That means
> function x(){}
> "use strict";
>
> Will enable strict mode, but
>
> (function x(){});
> "use strict";
>
> won't. To make your example strict, you'd have to do
>
> with (ob) {
> (function(){
> "use strict'";
> /* concatenated stuff */
> })();
> }
>
>
> On Wed, Jan 30, 2013 at 10:48 AM, Claude Pache <[email protected]> wrote:
> Le 30 janv. 2013 à 06:12, Andrea Giammarchi <[email protected]> a
> écrit :
>
>> I have a blog post about it called
>>
>> Resurrecting The With Statement
>>
>> and before I post the link, there the long story short:
>>
>> putting `with(this){` before any build process/inlined library and `}` at
>> the end of all concatenated files nobody is strict anymore ^_^
>
> For what I understand of ES5, putting some random stuff (other than string
> literals or comments) before a "use strict" directive at the beginning of a
> file will disable it. This is a known fact, orthogonal to the "Function +
> with" dirty/creative hack of your blog post.
>
> —Claude
>
>>
>> http://webreflection.blogspot.com/2013/01/resurrecting-with-statement.html
>
>>
>> I actually like this possibility, but I'd like to know what you think about
>> it
>>
>> br
>> _______________________________________________
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>
>
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