On Fri, 4 Jun 2010, Stefan O'Rear wrote:
On Sat, Jun 05, 2010 at 09:19:01AM +1000, Timothy S. Nelson wrote:
Hi. I've been thinking more about reversible grammars. Specifically,
I'm wondering if the following pseudo-code will be possible:
## Match a grammar here
$match = Grammar.match($text)
## Need some code here to get $submatch from $match
....
$submatch.Str = "fred"
## Reverse Grammar
$text = Grammar.reverse($match)
My idea is that I could read in a file, find the part I wanted in the
match tree, change that part, and then write it back to the file. Is
that going to be a possibility?
Look at emit_p5 in viv, where we do basically exactly that (but combined with
a recursive traversal).
Thanks. What I guess I'm really asking is, can we add an "emit"
method to the Match object in the P6 spec? Usually I just be bold and add
things, but I thought people might want to discuss this one first :).
Also, while I was trying to investigate this, I was wondering about
S32/Rules. I've added a few more lines to it, but there are some things
I'm having trouble figuring out (this may be due to a few months absence
from the p6 community -- sorry :) ). Anyway, my questions are:
Higher-numbered synopses are much more speculative, poorly implemented, and
get little love from the janitorial staff; so, in case of disagreement, the
lower number has the correct answer.
Yes, I know the lower ones are correct, but sometimes I have trouble
finding where they mention things (eg. I skimmed over S02 before posting this,
but because I was only looking at the tables of types, and not reading the
text, I missed StrPos).
- I note that, while S32/Rules says that .from returns an Int, S05 has a
call $/.from.bytes . Does this mean that there's a StringSize type
S32 is wrong.
Yes, I know that. I wrote most of it myself :).
that does maybe .bytes, .chars, .graphs, and .codes that's returned by
maybe .from, .to, and .pos ?
Yes, it's called StrPos; see S02:813.
Thanks! :)
I've also added "does Positional does Associative" to the Match role.
Does that make sense, or should I instead be adding methods with postfix ()
and postfix [] ?
:)
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| Name: Tim Nelson | Because the Creator is, |
| E-mail: wayl...@wayland.id.au | I am |
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