def simplify_division(node):
variable_ctrs = {}
order = []
for t in node:
if t.ch in set(ascii_lowercase) or str(t.ch).isdigit():
if t.ch not in variable_ctrs.keys():
order.append(str(t.ch))
variable_ctrs[str(t.ch)] = 0
if node[0].ch in set(ascii_lowercase):
node = tokenize('*') + node
for i in range(0, len(node), 2):
sign = node[i].ch
var = str(node[i + 1].ch)
if sign == '/':
variable_ctrs[var] -= 1
else:
variable_ctrs[var] += 1
new_node = []
for var in order:
if str(var) != '1':
ctr = variable_ctrs[var]
if ctr < 0:
new_node += ['/', var] * abs(ctr)
elif ctr > 0:
new_node += ['*', var] * ctr
else:
pass
if len(new_node) == 0:
return tokenize('1')
if new_node[0] == '/':
new_node = ['1'] + new_node
elif new_node[0] == '*':
new_node = new_node[1::]
new_node = tokenize(new_node)
return new_node
def add_zero(node):
if len(node) < 2:
return node
else:
if node[0].priority == 0:
node = tokenize('+') + node
new_node = []
for i in range(0, len(node) - 1, 2):
ch_1, ch_2 = node[i].ch, node[i + 1].ch
if str(ch_2) != '0':
new_node.append(str(ch_1))
new_node.append(str(ch_2))
new_node = tokenize(new_node)
return new_node
def mul_by_zero(node):
for i in range(len(node) - 1):
ch_1, ch_2 = node[i].ch, node[i + 1].ch
if str(ch_1) == '0' and str(ch_2) == '*':
new_node = ['0']
elif str(ch_1) == '*' and str(ch_2) == '0':
new_node = ['0']
else:
new_node = [str(t.ch) for t in node]
new_node = tokenize(new_node)
return new_node
def simplify_sum(node):
variable_ctrs = {}
order = []
for t in node:
if t.ch in set(ascii_lowercase) or str(t.ch).isdigit():
if t.ch not in variable_ctrs.keys():
order.append(str(t.ch))
variable_ctrs[str(t.ch)] = 0
if node[0].ch != '-':
node = tokenize('+') + node
for i in range(0, len(node), 2):
sign = node[i].ch
var = str(node[i + 1].ch)
if sign == '-':
variable_ctrs[var] -= 1
else:
variable_ctrs[var] += 1
new_node = []
for var in order:
ctr = variable_ctrs[var]
if ctr < 0:
ctr = [str(ctr)[1::]]
if ctr == ['1']:
ctr = []
else:
ctr += ['*']
new_node += ['-'] + ctr + [var]
elif ctr > 0:
ctr = [str(ctr)]
if ctr == ['1']:
ctr = ['+']
else:
ctr = ['+'] + ctr + ['*']
new_node += ctr + [var]
else:
pass
if len(new_node) == 0:
return tokenize('0')
new_node = tokenize(new_node)
return new_node
def simplify_with_var(node):
pos = node[0].pos
end_pos = node[-1].pos
digits = [i.ch for i in node if str(i.ch).isdigit()]
if len(node) > 4 and len(digits) > 1:
calculable = []
incalculable = []
tokens = node.copy()
first_var = []
prev_token = None
if tokens[0].ch in set(ascii_lowercase):
first_var.append(tokens.pop(0))
prev_token = first_var[0]
for token in tokens:
if token.ch in set(ascii_lowercase):
incalculable.append(prev_token)
incalculable.append(token)
elif str(token.ch).isdigit():
if prev_token:
calculable.append(prev_token)
calculable.append(token)
prev_token = token
incalculable = first_var + incalculable
calculable = merge_tokens(*calculable, integer_devision=True)
if incalculable[0].ch in set(ascii_lowercase):
if int(calculable[0].ch) < 0:
result = incalculable + tokenize('-') + calculable
else:
result = incalculable + tokenize('+') + calculable
else:
result = calculable + incalculable
else:
result = node
result[0].pos = pos
result[0].end_pos = end_pos
return result
def to_zero_pwr(node):
zero_pwr = 0
new_node = []
for token in node[::-1]:
if str(token.ch) == '0':
zero_pwr = 2
elif zero_pwr == 2:
zero_pwr -= 1
elif zero_pwr == 1:
zero_pwr -= 1
new_node += tokenize('1')
else:
new_node.append(token)
zero_pwr = False
return new_node[::-1]
def remove_dbl_neg(str_repr):
processed, sign, inner, cut_str = select_brackets(str_repr)
plus = ''
left = processed.replace('{}({}'.format(sign, inner), '', 1)
if left:
left += '+'
plus = '+'
tokens = tokenize(inner)
if sign == '-' and inner.startswith('-(') and inner.endswith(')'):
str_repr = left + inner[2:len(inner) - 1] + cut_str
elif len(tokens) == 2 and tokens[0].ch == '-':
str_repr = str_repr.replace('-({})'.format(inner), plus + inner[1], 1)
elif '(' not in inner:
# sqr brackets added to avoid processing same brackets twice
str_repr = str_repr.replace('(', '[', 1).replace(')', ']', 1)
return str_repr
def pre_process(self, graph):
return tokenize(graph)