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module Rsec
# Join base
class Join < Binary
def _parse ctx
e = left._parse ctx
return INVALID if INVALID[e]
ret = [e]
loop do
save_point = ctx.pos
i = right._parse ctx
if INVALID[i]
ctx.pos = save_point
break
end
t = left._parse ctx
if INVALID[t]
ctx.pos = save_point
break
end
break if save_point == ctx.pos # stop if no advance, prevent infinite loop
ret << i
ret << t
end # loop
ret
end
end
# keep only tokens
class JoinEven < Binary
def _parse ctx
e = left._parse ctx
return INVALID if INVALID[e]
ret = [e]
loop do
save_point = ctx.pos
i = right._parse ctx
if INVALID[i]
ctx.pos = save_point
break
end
t = left._parse ctx
if INVALID[t]
ctx.pos = save_point
break
end
break if save_point == ctx.pos # stop if no advance, prevent infinite loop
ret << t
end # loop
ret
end
end
# keep only inters
# NOTE if only 1 token matches, return empty array
class JoinOdd < Binary
def _parse ctx
e = left._parse ctx
return INVALID if INVALID[e]
ret = []
loop do
save_point = ctx.pos
i = right._parse ctx
if INVALID[i]
ctx.pos = save_point
break
end
t = left._parse ctx
if INVALID[t]
ctx.pos = save_point
break
end
break if save_point == ctx.pos # stop if no advance, prevent infinite loop
ret << i
end # loop
ret
end
end
end
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