grammar : production+

production : WORD_COLON expr action?

expr : expr '|' expr
     | '(' expr ')'
     | expr expr %prec SEQ
     | WORD_COLON_COLON expr
     | WORD 
     | STRING
     | expr '+'
     | expr '*'
     | expr '?'
     | expr '%prec' WORD

action : '{' WORD+ '}'


%%
# Lex Extra Stuff

tokens.append('WORD_COLON_COLON')
def t_WORD_COLON_COLON(t):
    r'[a-zA-Z_]:?[-a-zA-Z_0-9]*[ \t\n]*::'
    t.lexer.lineno += t.value.count('\n')
    t.value = t.value[:-2].strip()
    return t

tokens.append('WORD_COLON')
def t_WORD_COLON(t):
    r'[a-zA-Z_][-a-zA-Z_0-9]*[ \t\n]*:'
    t.lexer.lineno += t.value.count('\n')
    t.value = t.value[:-1].strip()
    return t

#tokens.append('PREC')
#def t_PREC(t):
#    r'%prec'
#    return t

tokens.append('WORD')
def t_WORD(t):
    r'[a-zA-Z_][-a-zA-Z_0-9]*'
    return t

tokens.append('STRING')
def t_STRING(t):
    r'''(("([^"]|\\"|\n)*")|('([^']|\\'|\n)*'))'''
    t.value = t.value[1:-1]
    t.value = t.value.replace(r'\"', '"')
    t.value = t.value.replace(r"\'", "'")
    t.value = t.value.replace(r'\n', '\n')
    t.lexer.lineno += t.value.count('\n')
    return t

##
##  sorta standard stuff
##

# DONT declare it a token -- yacc never sees these
# tokens.append('LINE_COMMENT')
def t_LINE_COMMENT(t):
    r'\#[^\n]*\n'
    t.lexer.lineno += t.value.count('\n')
    pass

# DONT declare it a token -- yacc never sees these
# tokens.append('C_COMMENT')
def t_C_COMMENT(t):
    r'/\*(.|\n)*?\*/'
    t.lexer.lineno += t.value.count('\n')
    pass

%%
# Yacc Extra Stuff

def p__EMPTY(t):
    '''EMPTY : '''
    pass


precedence = (
#    ('right', 'VERTICALBAR'),
    ('right', 'PERCENT_P_R_E_C'),
    ('right', 'SEQ'), # associativity doesn't work for %prec
    ('nonassoc', 'WORD_COLON_COLON'),
    ('left', 'PLUS', 'STAR', 'QUESTION'),
)