[REBOL] Re: reusing parse rules

From: david::vydra::net at: 23-Jan-2001 23:41

Andrew:

I've been playing :)

r1: [r1: [any r2]]
r2: [r2: [word!]]
my-parser: make object! compose [
(r1)
  (r2)
;-- you can even attach an action to an existing rule
  ([append r2 [( print "Found Word")]])
]

regards

david

 >>>>
Hi, David (and feedback), you wrote (directly:
> Have you found a satisfactory solution to reusing grammar rules?

Not yet. My best so far is to put common rules in an object like:
         Rules: make object! [
             Label: [Alpha some Alphanumeric]
             ]
     then refer to the rule in another object like:
         Parser: make object! [
             Label: Rules/Label
             Action: [
                 Label (
                     ; Do stuff here
                     )
                 ]
             ]
     My next thoughts are to request object/path support in 'parse rules from
Rebol HQ. Something like:
         Action: [
             Rules/Label (
                 ; My action here.
                 )
             ]
     would be good to add to Rebol's 'parse dialect.

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