# Main rule
eyapp:   +head +body +tail

# "Atoms"
E_CODE : /(
   <LCURLY>
   (:
      [^ <LCURLY><RCURLY> ]+ |  # Most stuff
      (?1)                      # Nesting braces
   )*
   <RCURLY>
)/
E_PERCODE  : / <PERCENT><E_CODE> ~ /  # bit of a hack
E_BEGINCODE: / <PERCENT> begin ~ <E_CODE> ~ /
E_IDENT    : / ( (: <ALPHA> | <UNDER> ) <WORD>* ) ~ /
E_LABEL    : / <COLON> <WORD>+ ~ /
E_LITERAL  : / <SINGLE> ([^ <SINGLE> ]+) <SINGLE> ~ /
E_NAME     : / <PERCENT> name ~ /
E_nameident: / (: <E_NAME> ~ <E_IDENT> ~ )? /
E_OPTION   : / <E_nameident> <QMARK> ~ /
E_PLUS     : / <E_nameident> <PLUS> ~ /
E_PREC     : / <PERCENT> prec ~ /
E_PLUS     : / <E_nameident> <STAR> ~ /
E_section  : / ~ <PERCENT><PERCENT> ~ /

# Common rules:
percode: E_PERCODE
symbol:  +literal | +token
literal: E_LITERAL
token:   E_IDENT

# Head section:
head:    decl* E_section
decl:    ( / <PERCENT><E_IDENT> <wsc> [ ^<DOS> ]* <EOL> / | +percode ) wsc

# Rule section
body:    rules* E_section
rules:   +comments ~ +lhs +rhs ~ <SEMI> ~
lhs:     / <E_IDENT> ~ <COLON> ~ /
rhs:     <rule>+ % / ~ <PIPE> ~ /
rule:    optname? ~ rhselt* ~ ( prec code? )?

rhselt:
     symbol
   | +code
   | +comment
   | .( E_PREC token )
   ### (not used in Pg.eyp)
   #| ( <LPAREN> optname? rhseltwithid* <RPAREN> )
   #| ( rhselt (
   #     E_STAR
   #   | E_OPTION
   #   | E_PLUS
   #   | ( <LANGLE> ( E_STAR | E_PLUS ) symbol <LANGLE> )
   #) )
   
optname: E_NAME ( ( E_IDENT E_LABEL? ) | E_LABEL )  # (not used in Pg.eyp)
prec:    E_PREC ~ symbol
code:    E_CODE | E_BEGINCODE

# Tail section:
tail:    / ( <ALL>+ ) /

# whitespace
wsc: / (: <WS> | <comment_null> )* /

comment_null: /
   <SLASH> <STAR>
   <ALL>*?
   <STAR> <SLASH> 
/

comment: / ~ ( <comment_null> ) ~ /
comments: comment*