# SYNTAX SUGAR
# string x string ==> string res@x string (if only one non-constant, make that res@)
# xs ==> {res} xs (if no command, make it res)


primRule  = clearWarn spaces name hexes digits
primMatch = name

root = tags

tags
    eof = {warn s0 []}
    _ = clearWarn x@tag xs@tags {warn s0 $ pos s0 $ x ++ xs}

tag
    "<!--" = comment
    "&" = entity
    "</" = close
    "<" = open
    _ = text

comment = (endBy "-->") {[Comment res]}

entity = entity1 ";"
entity1
    "#x" = hexes  {entityNameHashX res}
    "#"  = digits {entityNameHash  res} 
    _    = name   {entityName      res} 

close = spaces res@name spaces ">" {[Close res]} 

open = spaces x@name spaces xs@(atts x) {Open x (fst xs) : snd xs} 

atts param
    "/>" = {([],[Close param])}
    ">"  = {([],[])}
    "\"" = y@(str "\"") spaces res@(atts param) {first (("",y):) res}
    "\'" = y@(str "\'") spaces res@(atts param) {first (("",y):) res}
    x@name = spaces y@attEq spaces res@(atts param) {first ((x,y):) res}
    _    = ">" {([],[])}

# ="bar"
attEq
    "=" = spaces res@attQuote
    _ = spaces {""}

# "bar"
attQuote
    "\"" = (str "\"")
    "'" = (str "'")
    _ = {""}

# bar"
str param
    eof = param
    param = {[]}
    "&" = x@entity xs@(str param) {innerTexts x ++ xs}
    _ = x@(takeWhileNot "&" param) xs@(str param) {x ++ xs} 

text = (takeWhileNot "<&") {[Text res]}