While this would greatly affect Match.jl, it would be a very welcome change!
Cheers,
Kevin
On Saturday, September 13, 2014, Leah Hanson <astriea...@gmail.com> wrote:
> I would expect the Expr type to be abstract, with different concrete
> subtypes for each current value of head. Each value of head indicates a
> specific structure in args, and this can just be reflected in the
> definition of the subtypes. (Then you can dispatch on Expr type, use
> "subtypes(Expr)" to see all possible kinds of Expr, etc.)
>
> -- Leah
>
> On Sat, Sep 13, 2014 at 10:47 AM, Jake Bolewski <jakebolew...@gmail.com
> <javascript:_e(%7B%7D,'cvml','jakebolew...@gmail.com');>> wrote:
>
>> We've actually discussed changing our expression representation to use
>>>> types instead of the more lisp-like symbols for distinguishing expression
>>>> types. That would allow dispatch on expression types and be more compact.
>>>> It would, however, break almost all macros that do any kind of expression
>>>> inspection.
>>>>
>>>
>> Hmm, interesting. I guess the Expr type would then be Expr{:head} with
>> getindex / setindex overloaded to manipulate the arguments? This would be
>> a nice change as for many nodes you would not have to allocate an args
>> array which could be a performance win (i guess the serialized ast's would
>> be more compact as well). Can't comment on whether it would be enough of a
>> win to justify such a massively breaking change.
>>
>>
>>> On Sat, Sep 13, 2014 at 2:48 AM, Gray Calhoun <gcal...@iastate.edu>
>>>> wrote:
>>>>
>>>>> On Wednesday, September 10, 2014 11:50:44 AM UTC-5, Steven G. Johnson
>>>>> wrote:
>>>>>>
>>>>>> On Wednesday, September 10, 2014 12:20:59 PM UTC-4, Gray Calhoun
>>>>>> wrote:
>>>>>>>
>>>>>>> Are there better ways to do this in general?
>>>>>>>
>>>>>>
>>>>>> For this kind of expression-matching code, you may find the Match.jl
>>>>>> package handy (https://github.com/kmsquire/Match.jl), to get ML- or
>>>>>> Scala-like symbolic pattern-matching.
>>>>>>
>>>>>
>>>>> Thanks, that's pretty cool. For simple cases like I'm using, do you
>>>>> know if there are advantages (or disadvantages) to using Match.jl, or
>>>>> should I just view it as a nicer syntax? (Obviously, when things get more
>>>>> complicated Match.jl looks very appealing).
>>>>>
>>>>
>>>>
>
