Re: [Spirit-general] Parsing of non-strings.

[Flogromp N. <loo...@gm...>]

An example message coming in from Max/MSP might be a linked-list of
tagged-unions which contain the following message each as individual atoms.

"global" "{" "freq" 255 "cutoff" 444 "flop" 0.9 "}" "myvoice" "{" 0 "{"
"note" "c-4" "samp" 12 "velo" 80 "fxcmd" "{" 0 "[" "e" 8 "]" 1 "[" "p" -127
"]" "}" "}" 1 "{" "note" "e-4" "samp" 11 "}" "}"

Joel, please help further.


On Nov 29, 2007 4:47 PM, Flogromp N. <loo...@gm...> wrote:

> CARL,
>
> There *is no file*. I am never loading any file, reading any file, or
> working with any data in any chunks or any file format of any kind. I am not
> parsing any string.
>
> The data is specifically in a linked list of tagged-unions.
>
> These are realtime messages being parsed which come from the dataflow
> programming language for Music called Max/MSP. You can check it out at
> http://cycling74.com
>
> I looks like this:
>
> http://interactive.usc.edu/members/mtuters/Picture%201.png
>
> Do you see those little objects? I'm creating one of those.
> The linked list of tagged unions is a MESSAGE which travels over those
> wires during the interrupt. The Max/MSP SDK provides messages in this
> format.
> I need to make sure my CPU usage from parsing is low, so that there's
> plenty of power left for DSP processing.
>
> I think perhaps Joel Guzman ignored helping me because he thinks I am
> trying to use some kind of external lexer which is not the case at all :(
>
> - Flogromp N.
>
>
>
>    lets see the file format is any combination of four chunks and each
> > chunk contains a type in N. bytes
> >
> >    integer_chunk:
> >        tag: N bytes
> >        long M bytes
> >   float_chunk:
> >        tag: N bytes
> >        float: P bytes
> >   string_chunk:
> >        tag: N bytes
> >        data:  '\0' stream of chars unlimited size.
> >   object_chunk:
> >        tag: N bytes
> >        object_data:  some computable size
> >
> > if the object size  is variable we need to parse the file from the
> > point after the tag was read until
> > object is computed . if its fixed size we can gather the data and parse
> > it. [spirit or ad_hoc depending
> > on complexity]
> >
> > so it seams that you really need only to parse a string [possibly an
> > Object] via spirit.  so if you have
> > a grammar that parses the string into an other string then you can
> > store the results of everything
> > in a vector<boost;:variant<long,float,std::string,Object> and write one
> > visitor use to process the
> > contents of the vector.   the visitor is really a functor with
> > opertor() overloaded for each type in
> > the variant.
> >
>
>