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%{
import System
import Char
import Alex
%}
"pp_lx"/"pp_acts":-
{ ^s = ^w#^n } -- spaces and tabs, etc.
{ ^f = [A-Za-z0-9`~%-_.,/'] } -- file name character
<inc> ::= ^#include^s+^"^f+^"^s*^n
<txt> ::= .*^n
%{
inc p c inp len cont st = pp fn >> cont st
where
fn = (takeWhile ('"'/=) . tail . dropWhile isSpace . drop 8) inp
txt p c inp len cont st = putStr (take len inp) >> cont st
main:: IO ()
main = getArgs >>= \args ->
case args of
[fn] -> pp fn
_ -> error "usage: pp file\n"
pp:: String -> IO ()
pp fn = readFile fn >>= \cts -> gscan pp_scan () cts
pp_scan:: GScan () (IO ())
pp_scan = load_gscan (pp_acts,stop_act) pp_lx
where
stop_act _ _ _ _ = return ()
%}
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