[REBOL] Re: brainfart parse problem
From: gjones05:mail:orion at: 6-Jun-2001 16:55
> > From: "Erin Thomas"
> > > >> rule: [thru "x" copy a [ opt to "y" | to "z"]]
> > > == [thru "x" copy a [opt to "y" | to "z"]]
> > > >> parse "x .... ab z cd y" rule
> > > == false
> > > >> a
> > > == " .... ab z cd "
> > >
> > > now... how do i work the rule so it will stop at "z"
> > > if "z" happens to be before "y"?
> Ladislav Mecir wrote:
> >
> > valid: complement charset "xz"
> > parse "x .... ab z cd y" [thru #"x" copy a [any valid] to end] ; ==
true
> > a ; == " .... ab "
From: "Erin Thomas"
> this is kind of what i want, but the "valid"s
> aren't individual characters, they are a series
> of characters, so doing a charset is out. how
> would i get the same effect given that the "z"
> and "y" were actually "zyx" and "yza"?
How about:
a: copy ""
rule: [
thru "x"
start:
[to "z" | to "y"]
ending:
(a: copy/part start ending)
to end
]
parse/all "x .... ab zyx cd yza" rule
print a ; yields: .... ab
--Scott Jones
