Cleaned up the AST code and updated the calc_engine code.

This commit is contained in:
2020-07-01 21:40:18 -05:00
parent fcd0076891
commit 503b16ec65
2 changed files with 44 additions and 271 deletions
+7 -143
View File
@@ -1,142 +1,17 @@
import ptoken
import tokenizer
import copy
from collections import deque
import parser
debug = False
def calculate_results(tokens):
# Main entry into the calc_engine.
# Returns the result of arthmetic as described by the token list.
return process_tokens(tokens, True)
def calculate_results(node):
def process_tokens(tokens, top_level = False):
pending_operations = []
running_total = 0
# Flag that inidicates a high priority set of mathmatical operations have occurred.
# High priority (mulitplation, division, power for instance) act as a pivot on which we can
# determine whether or not lower priority operations can safely be performed without violating
# the order of operations.
p_ops_ran = False
if type(node) is parser.Num:
return float(node.value)
while True:
if not tokens:
break
token = tokens.popleft()
if not top_level and token.type == ptoken.TokenType.exp_end:
if tokens:
look_ahead = tokens[0]
if look_ahead.type == ptoken.TokenType.power:
tokens.popleft()
two_ahead = tokens.popleft()
tmp = process_tokens(convert_to_deque(pending_operations))
if two_ahead.type == ptoken.TokenType.exp_start:
two_ahead = ptoken.Token(process_tokens(tokens), ptoken.TokenType.constant)
return operate(tmp, two_ahead.value, look_ahead.type)
break
if token.type == ptoken.TokenType.exp_start:
tmp = process_tokens(tokens)
pending_operations.append(ptoken.Token(tmp, ptoken.TokenType.constant))
elif token.type == ptoken.TokenType.power:
look_ahead = tokens.popleft()
#if look_ahead.type == ptoken.TokenType.exp_start:
# look_ahead = ptoken.Token(process_tokens(tokens), ptoken.TokenType.constant)
pending_operations.append(ptoken.Token(operate(pending_operations.pop().value, look_ahead.value, token.type), ptoken.TokenType.constant))
elif token.type == ptoken.TokenType.add or token.type == ptoken.TokenType.subtract:
if pending_operations and p_ops_ran:
tmp = convert_to_deque(pending_operations)
previous_token = ptoken.Token(handle_pending(tmp), ptoken.TokenType.constant)
pending_operations = []
pending_operations.append(previous_token)
pending_operations.append(token)
p_ops_ran = False
elif token.type == ptoken.TokenType.constant:
pending_operations.append(token)
p_ops_ran = False
elif token.type == ptoken.TokenType.multiply or token.type == ptoken.TokenType.divide:
look_behind = pending_operations.pop()
look_ahead = tokens.popleft()
two_ahead = tokens[0]
if look_ahead.type == ptoken.TokenType.exp_start:
look_ahead = ptoken.Token(process_tokens(tokens), ptoken.TokenType.constant)
if two_ahead.type == ptoken.TokenType.power:
tokens.popleft()
three_ahead = tokens.popleft()
if three_ahead.type != ptoken.TokenType.exp_start:
look_ahead = ptoken.Token(operate(look_ahead.value, three_ahead.value, two_ahead.type), ptoken.TokenType.constant)
else:
tmp = process_tokens(tokens)
look_ahead = ptoken.Token(operate(look_ahead.value, tmp, two_ahead.type), ptoken.TokenType.constant)
running_total = operate(look_behind.value, look_ahead.value, token.type)
pending_operations.append(ptoken.Token(running_total, ptoken.TokenType.constant))
p_ops_ran = True
#tokenizer.print_token_list(pending_operations)
if pending_operations:
if len(pending_operations) == 1:
return float(pending_operations.pop().value)
return handle_pending(convert_to_deque(pending_operations))
return running_total
#handle add/sub
def handle_pending(tokens):
# Effectively, this function handles adding and subtracting as all higher priority mathmatical operations
# would have already been processed.
# Returns the result of the addition or subtraction of the provided token list.
running_total = 0
previous_token = None
if len(tokens) == 1:
return float(tokens[0].value)
while True:
if not tokens:
break
tmp_token = tokens.popleft()
if tmp_token.type == ptoken.TokenType.constant:
previous_token = tmp_token
elif tmp_token.type == ptoken.TokenType.add or tmp_token.type == ptoken.TokenType.subtract:
look_ahead = tokens.popleft()
running_total = operate(previous_token.value, look_ahead.value, tmp_token.type)
previous_token = ptoken.Token(running_total, ptoken.TokenType.constant)
return running_total
def convert_to_deque(tokens):
# Converts a list into a Deque collection object.
# Returns a Deque object with the contents of the supplied list or array.
deq = deque()
for tk in tokens:
deq.append(tk)
return deq
left = calculate_results(node.left)
right = calculate_results(node.right)
return operate(left, right, node.op)
def operate(n1, n2, tokenType):
# Utility function to handle dealing with the various mathmatical operations that the engine can process.
@@ -161,14 +36,3 @@ def operate(n1, n2, tokenType):
return n1 ** n2
else:
raise TypeError("Invalid operator value " + str(tokenType) + ".", tokenType)
def print_t(tokens):
# Prints to standard out a flattened representation of a Deque object.
tmp = copy.deepcopy(tokens)
while True:
if not tmp:
break
token = tmp.popleft()
print("%s" %(token.value), end = "")
print()
+37 -128
View File
@@ -1,7 +1,6 @@
import ptoken as token
import tokenizer
import uuid
import calc_engine
from collections import deque
class Op:
@@ -20,55 +19,63 @@ class Num:
def __str__(self):
return self.value
class Variable:
def __init__(self, token):
self.symbol = token.value
self.value = None
def __str__(self):
if self.value == None:
return self.symbol
else:
return str(self.value)
class Parser:
def __init__(self, tokens):
if len(tokens) == 0:
raise ValueError("Token list can't be empty")
self.tokens = tokens
self.current_token = self.tokens.popleft()
self.current_token = None
self.advance_current_token()
self.ast = self.generate_ast()
def eat(self, token_type):
if self.current_token.type != token_type:
print("grammar")
def advance_current_token(self):
if len(self.tokens) > 0:
self.current_token = self.tokens.popleft()
def factor(self):
node = self.current_token
#print(node)
if self.current_token.type == token.TokenType.constant:
self.eat(token.TokenType.constant)
return Num(node)
node = Num(self.current_token)
self.advance_current_token()
return node
elif self.current_token.type == token.TokenType.variable:
node = Variable(self.current_token)
self.advance_current_token()
return node
elif self.current_token.type == token.TokenType.exp_start:
self.eat(token.TokenType.exp_start)
self.advance_current_token() # (
node = self.topLevel()
self.eat(token.TokenType.exp_end)
self.advance_current_token() # )
return node
def lowLevel(self):
node = self.factor()
while self.current_token.type == token.TokenType.power:
t = self.current_token
if t.type == token.TokenType.power:
self.eat(token.TokenType.power)
tmp = self.current_token
self.advance_current_token()
node = Op(left=node, op=tmp.type, right=self.factor())
node = Op(left=node, op=t.type, right=self.factor())
return node
def midLevel(self):
node = self.lowLevel()
while self.current_token.type in (token.TokenType.multiply, token.TokenType.divide):
t = self.current_token
if t.type == token.TokenType.multiply:
self.eat(token.TokenType.multiply)
elif t.type == token.TokenType.divide:
self.eat(token.TokenType.divide)
node = Op(left=node, op=t.type, right=self.lowLevel())
tmp = self.current_token
self.advance_current_token()
node = Op(left=node, op=tmp.type, right=self.lowLevel())
return node
@@ -76,109 +83,11 @@ class Parser:
node = self.midLevel()
while self.current_token.type in (token.TokenType.add, token.TokenType.subtract):
t = self.current_token
if t.type == token.TokenType.add:
self.eat(token.TokenType.add)
elif t.type == token.TokenType.subtract:
self.eat(token.TokenType.subtract)
node = Op(left=node, op=t.type, right=self.midLevel())
tmp = self.current_token
self.advance_current_token()
node = Op(left=node, op=tmp.type, right=self.midLevel())
return node
def parse(self):
#print("C: %s" %(self.current_token))
def generate_ast(self):
return self.topLevel()
def print_tree(root):
depth = Parser.get_tree_diameter(root)
for i in range(depth):
print("%s" %("".rjust(depth - i, ' ')), end = "" )
Parser.print_height(root, i)
print()
def print_height(node, level):
if node == None:
return
if level == 0:
print("%s " %(str(node)), end = "")
else:
Parser.print_height(node.left, level - 1)
Parser.print_height(node.right, level - 1)
def get_tree_diameter(node):
if type(node) is Num:
return 0
if node == None:
return 0
return 1 + max(Parser.get_tree_diameter(node.left), Parser.get_tree_diameter(node.right))
def p(node):
if type(node) is Num:
#print("%s " %(node), end ="")
return
else:
#Parser.p(node.left)
print(node)
#Parser.p(node.right)
Parser.p(node.left)
Parser.p(node.right)
def calc(node):
if type(node) is Num:
return float(node.value)
left = calc(node.left)
right = calc(node.right)
return operate(left, right, node.op)
debug = False
def operate(n1, n2, tokenType):
# Utility function to handle dealing with the various mathmatical operations that the engine can process.
# Returns the result of any one of five mathmatical operations, else throws an error for unrecognized operations.
n1 = float(n1)
n2 = float(n2)
if tokenType == token.TokenType.add:
if debug: print("Adding %f and %f to get %f." %(n1, n2, n1 + n2))
return n1 + n2
elif tokenType == token.TokenType.subtract:
if debug: print("Subtracting %f and %f to get %f." %(n1, n2, n1 - n2))
return n1 - n2
elif tokenType == token.TokenType.multiply:
if debug: print("Multiplying %f and %f to get %f" %(n1, n2, n1 * n2))
return n1 * n2
elif tokenType == token.TokenType.divide:
if debug: print("Dividing %f and %f to get %f" %(n1, n2, n1 / n2))
return n1 / n2
elif tokenType == token.TokenType.power:
if debug: print("Raising %f to the power of %f to get %f" %(n1, n2, n1**n2))
return n1 ** n2
else:
raise TypeError("Invalid operator value " + str(tokenType) + ".", tokenType)
# k(((1+i)^n - 1)/i)
#t = Add()
#t.add_child(Constant(4))
#t.add_child(Sub())
#t.left.add_child(Sub())
tokens = tokenizer.get_tokens_from_expression_string("5*2^(2+1)-(1+5)-2^5+5*(2/2*3+5)^2")
#tokens.reverse()
#print(calc_engine.calculate_results(tokens))
#tokens = tokenizer.get_tokens_from_expression_string("200((1-(1.08)^(-12))/0.08)")
#print(calc_engine.calculate_results(tokens))
#tokens = tokenizer.get_tokens_from_expression_string("1+6 / 2")
n = Parser(tokens)
s = n.parse()
#Parser.p(s)
print(calc(s))