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Re: Is there a better way?

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WJ wrote:

> Mark Wills wrote:
> 
> > The following routine is checking to see if a string is "}}" i.e.
> > consists of two consequtive right curly braces.
> > 
> > : }}? ( addr len -- addr len flag)
> >   dup 2= if
> >     over dup c@   swap 1+ c@   125 =   swap 125 =   and
> >   else
> >     false
> >   then ;
> > 
> > As can be seen, the first check is the length; if the length is not
> > exactly 2 then we just return false. If the length is 2 then we check
> > to see if both characters are ASCII 125. That's the bit I am looking
> > at and saying "Meh... seems a bit convoluted/lengthy.
> > 
> > Is there a better way?
> > 
> > I was thinking maybe:
> > 
> > ... c@ 125 OR swap   1+ c@ 125 OR  125 XOR 0=
> > 
> > Which is perhaps "cleverer" but not as clear as to the intention of
> > the code and no shorter...
> 
> Factor:
> 
> "}}" "}}" = .
> t
> 
> "}}" "@@" = .
> f

Oforth:

 > "}}" "}}" == println
 -1
 ok
 > "}}" "}" == println
 0
 ok
 > "}}" "}?" == println
 0

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Re: Is there a better way? "WJ" <w_a_x_man@yahoo.com> - 2015-03-27 06:03 +0000

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