import string
from parser import Parser
mapping = {
1: "family",
2: "person",
3: "firstName",
4: "lastName",
5: "state",
}
def parse_int(i, xs):
result = ""
while i < len(xs) and xs[i] in string.digits:
result += xs[i]
i += 1
return i, int(result)
def parse_string(i, xs):
result = ""
while xs[i+1] not in string.digits:
result += xs[i]
i += 1
return i, result
def tokenize(xs):
result = []
i = 0
while i < len(xs):
if xs[i] in string.digits:
i, n = parse_int(i, xs)
result.append(n)
elif xs[i] in string.ascii_letters:
i, x = parse_string(i, xs)
result.append(x)
elif xs[i] == " ":
i += 1
continue
return result
def parse(xs):
parser = Parser(tokenize(xs))
return parse_element(parser)
# Element -> Tag Attribute* End Element* End ;
# Tag -> INTEGER ;
# Value -> STRING End ;
# Attribute -> Tag Value ;
# End -> 0 ;
def parse_element(parser):
if type(parser.curr()) == str:
return parser.consume()
tag_id = parser.expect_predicate(lambda x: type(x) == int)
tag = mapping[tag_id]
attrs = parse_attrs(parser)
parser.expect([0])
children = []
while not parser.exhausted() and parser.curr() != 0:
children.append(parse_element(parser))
parser.expect([0])
return [tag, attrs, children]
def parse_attrs(parser):
result = []
while parser.curr() != 0:
tag_id = parser.expect_predicate(lambda x: type(x) == int)
tag = mapping[tag_id]
value = parser.consume()
result.append((tag, value))
return result
def stringify_xml(tree, indent=0):
if type(tree) == str:
return tree
result = ""
tag, attrs, children = tree
str_attrs = []
for k, v in attrs:
str_attrs.append("{}=\"{}\"".format(k, v))
str_attrs = (" " if str_attrs else "") + " ".join(str_attrs)
str_children = []
for child in children:
str_children.append(" " * 2 * indent + stringify_xml(child, indent + 1))
str_children = "\n".join(str_children)
result += "{}<{}{}>\n{}{}\n{}</{}>".format(
" " * 2 * indent, tag, str_attrs, " " * 2 * indent, str_children,
" " * 2 * indent, tag)
return result
x = "1 4 McDowell 5 CA 0 2 3 Gayle 0 Some Message 0 0"
print("Input: {}".format(x))
print("Tokens: {}".format(tokenize(x)))
print("Parsed: {}".format(parse(x)))
print("{}".format(stringify_xml(parse(x))))
