package main

type URN Peg {

}

URN <- URN_PREFIX NID colon NSS eot

URN_PREFIX <- "urn" colon

NID <- LET_NUM LET_NUM_HYP?

NSS <- CHARS+

LET_NUM <- upper+ / lower+ / number+

LET_NUM_HYP <- LET_NUM / hyp

CHARS <- TRANS / perc HEX HEX

TRANS <- LET_NUM / OTHER / RESERVED 

HEX <- number+ / [A-F]+ / [a-f]+

OTHER <- '(' / ')' / '+' / ',' / hyp / '.' / colon / '=' / '@' / ';' / '$' / '_' / '!' / '*' / '\''

RESERVED <- perc / '/' / '?' / '#'

colon <- ':'

eot <- !.

upper <- [A-Z]

lower <- [a-z]

number <- [0-9]

hyp <- '-'

perc <- '%'