# replaces the '%' symbol with '+', leaving the return values of actions usable for other things, such as type information,
# and leaving whitespace intact.

from dparser import Parser

# turn a tree of strings into a single string (slowly):
def stringify(s):
    if type(s) == str:
        return s
    out = ''
    for c in s:
        out += stringify(c)
    return out

def d_add1(t, s):
    "add : add '%' exp"
    s[1] = '+ '             # replace the % with +

def d_add2(t, s):
    "add : exp"

def d_exp(t):
    'exp : "[0-9]+" '

# if the start action specifies the 's' argument, then parser
# will contain a member, s, 

parser = Parser()
parser.parse('1 % 2 % 3')
if stringify(parser.s) != '1 + 2 + 3':
    print 'error'