LPeg-anywhere

match anywhere, even backwards (see README for details)

Added 3 lpeg functions:

lpeg.B(-n) move back n bytes 
lpeg.B(-patt) move back fixedlen(patt) 

lpeg.N(patt) return a set of non-head-chars, useful for optimized search

lpeg.M(patt, skip) (lua function in re.lua) that can match anywhere FAST

Example: return 2 captures ". -and(. *)" and ". *and(. *)"
t = "this and that and this and more"

-- Using lpeg:
all = lpeg.C(lpeg.P(1)^0)
pat = lpeg.M('and') * all * lpeg.M('and', lpeg.B(-1)) * all

= lpeg.match(pat, t)
that and this and more       more 

-- Using lpeg re:
-- For convenience, re.lua added '>' and '<' prefix for forward and backward match: 

= re.match(t, ">'and' {. *} <'and' {. *}")
that and this and more       more