def test_single_number(self):
token = Token()
token.type = "number"
token.value = "123.456"
tokens = [token]
self.parser.set_tokens(tokens)
expression_tree = self.parser.get_expression_tree()
assert expression_tree is not None
assert expression_tree["node_type"] == "number"
assert expression_tree["value"] == 123.456
def make_rpn(self, expression):
"""
Parse an excel formula expression into reverse polish notation
Core algorithm taken from wikipedia with varargs extensions from
http://www.kallisti.net.nz/blog/2008/02/extension-to-the-shunting-yard-
algorithm-to-allow-variable-numbers-of-arguments-to-functions/
"""
"""
Parse an excel formula expression into reverse polish notation
Core algorithm taken from wikipedia with varargs extensions from
http://www.kallisti.net.nz/blog/2008/02/extension-to-the-shunting-yard-
algorithm-to-allow-variable-numbers-of-arguments-to-functions/
"""
lexer = Tokenizer(expression)
# amend token stream to ease code production
tokens = []
for token, next_token in zip(lexer.items, lexer.items[1:] + [None]):
if token.matches(Token.FUNC, Token.OPEN):
tokens.append(token)
token = Token('(', Token.PAREN, Token.OPEN)
elif token.matches(Token.FUNC, Token.CLOSE):
token = Token(')', Token.PAREN, Token.CLOSE)
elif token.matches(Token.ARRAY, Token.OPEN):
tokens.append(token)
tokens.append(Token('(', Token.PAREN, Token.OPEN))
tokens.append(Token('', Token.ARRAYROW, Token.OPEN))
token = Token('(', Token.PAREN, Token.OPEN)
elif token.matches(Token.ARRAY, Token.CLOSE):
tokens.append(token)
token = Token(')', Token.PAREN, Token.CLOSE)
elif token.matches(Token.SEP, Token.ROW):
tokens.append(Token(')', Token.PAREN, Token.CLOSE))
tokens.append(Token(',', Token.SEP, Token.ARG))
tokens.append(Token('', Token.ARRAYROW, Token.OPEN))
token = Token('(', Token.PAREN, Token.OPEN)
elif token.matches(Token.PAREN, Token.OPEN):
token.value = '('
elif token.matches(Token.PAREN, Token.CLOSE):
token.value = ')'
tokens.append(token)
output = []
stack = []
were_values = []
arg_count = []
# shunting yard start
for token in tokens:
if token.type == token.OPERAND:
output.append(self.make_node(token))
if were_values:
were_values[-1] = True
elif token.type != token.PAREN and token.subtype == token.OPEN:
if token.type in (token.ARRAY, Token.ARRAYROW):
token = Token(token.type, token.type, token.subtype)
stack.append(token)
arg_count.append(0)
if were_values:
were_values[-1] = True
were_values.append(False)
elif token.type == token.SEP:
while stack and (stack[-1].subtype != token.OPEN):
output.append(self.make_node(stack.pop()))
if not len(were_values):
raise FormulaParserError(
"Mismatched or misplaced parentheses")
were_values.pop()
arg_count[-1] += 1
were_values.append(False)
elif token.is_operator:
while stack and stack[-1].is_operator:
if token.precedence < stack[-1].precedence:
output.append(self.make_node(stack.pop()))
else:
break
stack.append(token)
elif token.subtype == token.OPEN:
assert token.type in (token.FUNC, token.PAREN, token.ARRAY)
stack.append(token)
elif token.subtype == token.CLOSE:
while stack and stack[-1].subtype != Token.OPEN:
output.append(self.make_node(stack.pop()))
if not stack:
raise FormulaParserError(
"Mismatched or misplaced parentheses")
stack.pop()
if stack and stack[-1].is_funcopen:
f = self.make_node((stack.pop()))
f.num_args = arg_count.pop() + int(were_values.pop())
output.append(f)
else:
assert token.type == token.WSPACE, \
'Unexpected token: {}'.format(token)
while stack:
if stack[-1].subtype in (Token.OPEN, Token.CLOSE):
raise FormulaParserError("Mismatched or misplaced parentheses")
output.append(self.make_node(stack.pop()))
return output
