Nested Quasis

Mike Samuel mikesamuel at gmail.com
Wed Feb 1 12:12:08 PST 2012


2012/2/1 Waldemar Horwat <waldemar at google.com>:
> On 01/31/2012 03:04 PM, Allen Wirfs-Brock wrote:
>>
>>
>> On Jan 31, 2012, at 2:36 PM, Waldemar Horwat wrote:
>>
>>> On 01/28/2012 02:54 PM, Erik Arvidsson wrote:
>>>>
>>>> Under the open issues for Quasi Literals,
>>>> http://wiki.ecmascript.org/doku.php?id=harmony:quasis#nesting , the
>>>> topic of nesting is brought up.
>>>>
>>>> After implementing Quasi Literals in Traceur it is clear that
>>>> supporting nested quasi literals is easier than not supporting them.
>>>> What is the argument for not supporting nesting? Can we resolve this?
>>>
>>>
>>> This has been hashed out in committee before.  Do you have a solution to
>>> the grammar problems, such as having a full ECMAScript parser inside the
>>> lexer?  You can't just count parentheses because that breaks regexps.
>>
>>
>> I would think the solution to this is pretty straightforward.  Basically,
>> a Quasi is not a single token.   the grammar in the proposal can almost be
>> read that way right now.   It should only take a little cleanup to factor it
>> into a pure lexical part and a syntactic part.
>
>
> I'd love to see this little cleanup.  I thought about it for a while and
> couldn't come up with it myself; I'm not sure it can even be done.

What should I put in the proposal?  A delta to the lexical grammar?


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