[Laszlo-dev] For Review: Change 20080518-dda-6 Summary: Script compiler line number rework

[Donald Anderson]

Aha - thanks, that was baffling.
I'll fix the comment accordingly.

I assume you're still reviewing this.

On May 19, 2008, at 9:16 AM, P T Withington wrote:

> On 2008-05-18, at 16:16 EDT, Donald Anderson wrote:
>
>>      Also observed during testing is the necessity of not breaking  
>> output
>>      lines to insert /* -*- file: .... */ comments.  This breaks  
>> lzunit
>>      test/lztest/lztest-node-options.js in a strange manner:
>>
>>           [exec] js: "test/lztest/lztest-node-options.js", line  
>> 108: uncaught JavaScript runtime exception: TypeError:  
>> org.mozilla.javascript.Undefined at 992bae is not a function, it is  
>> org.mozilla.javascript.Undefined.
>
> This is probably because Javascript has 'implicit semi-colons'.  The  
> parser rule is that if you see a line break where a semi would be  
> accepted, pretend you saw a semi.  Unfortunately that makes:
>
>  return
>  foo
>
> Parse as:
>
>  return;
>  foo;
>
> And your function returns no value and `foo` becomes unreachable code.
>
> (In JS2 they have fixed this by not permitting an implicit semi  
> between return and an expression.)


--

Don Anderson
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