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pegs: captured search loop

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Araq 2010-11-07 23:52:41 +01:00
commit 8ee63f9836
3 changed files with 55 additions and 5 deletions
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6
doc/pegdocs.txt
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@ -66,6 +66,10 @@ notation meaning
failure.
``@E`` Search: Shorthand for ``(!E .)* E``. (Search loop for the
pattern `E`.)
``{@} E`` Captured Search: Shorthand for ``{(!E .)*} E``. (Search
loop for the pattern `E`.) Everything until and exluding
`E` is captured.
``@@ E`` Same as ``{@} E``.
``A <- E`` Rule: Bind the expression `E` to the *nonterminal symbol*
`A`. **Left recursive rules are not possible and crash the
matching engine.**
@ -131,7 +135,7 @@ The PEG parser implements this grammar (written in PEG syntax)::
rule <- identifier \s* "<-" expr ig
identNoArrow <- identifier !(\s* "<-")
prefixOpr <- ig '&' / ig '!' / ig '@'
prefixOpr <- ig '&' / ig '!' / ig '@' / ig '{@}' / ig '@@'
literal <- ig identifier? '$' [0-9]+
ig identNoArrow /
ig charset /