From fcd0076891b70f1d0900726dce69961af253199b Mon Sep 17 00:00:00 2001
From: Garritt McCune <glmccune@gmail.com>
Date: Wed, 1 Jul 2020 19:28:09 -0500
Subject: [PATCH] Updated the tokenizer to use a deque object instead of a
 list. The old calc_engine should still work, not tested. New parser code
 works with this change.

---
 calc_engine.py |  2 +-
 parser.py      | 13 +++++++------
 tokenizer.py   | 19 ++-----------------
 3 files changed, 10 insertions(+), 24 deletions(-)

diff --git a/calc_engine.py b/calc_engine.py
index fe3af66..4db0f4b 100644
--- a/calc_engine.py
+++ b/calc_engine.py
@@ -8,7 +8,7 @@ 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(convert_to_deque(tokens), True)
+	return process_tokens(tokens, True)
 	
 def process_tokens(tokens, top_level = False):
 	pending_operations = []
diff --git a/parser.py b/parser.py
index 900c5cd..84c4615 100644
--- a/parser.py
+++ b/parser.py
@@ -2,6 +2,7 @@ import ptoken as token
 import tokenizer
 import uuid
 import calc_engine
+from collections import deque
 
 class Op:
 	def __init__(self, left, op, right):
@@ -22,14 +23,14 @@ class Num:
 class Parser:
 	def __init__(self, tokens):
 		self.tokens = tokens
-		self.current_token = self.tokens.pop()
+		self.current_token = self.tokens.popleft()
 		
 		
 	def eat(self, token_type):
 		if self.current_token.type != token_type:
 			print("grammar")
 		if len(self.tokens) > 0:
-			self.current_token = self.tokens.pop()
+			self.current_token = self.tokens.popleft()
 		
 	def factor(self):
 		node = self.current_token
@@ -140,7 +141,7 @@ def calc(node):
 	
 	return operate(left, right, node.op)
 		
-debug = True
+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.
@@ -177,7 +178,7 @@ tokens = tokenizer.get_tokens_from_expression_string("5*2^(2+1)-(1+5)-2^5+5*(2/2
 #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()
+n = Parser(tokens)
+s = n.parse()
 #Parser.p(s)
-#print(calc(s))
+print(calc(s))
diff --git a/tokenizer.py b/tokenizer.py
index 61b6ea6..1f5047a 100644
--- a/tokenizer.py
+++ b/tokenizer.py
@@ -1,10 +1,11 @@
 import ptoken as token
+from collections import deque
 
 def get_tokens_from_expression_string(expression_string):
 	# Takes user input (in the format of a string) of an actuarial formula and parses the formula to its components.
 	# Returns the list of Token objects that represent the string expression.
 	
-	tokens = []  # List of objects of Token class
+	tokens = deque()
 	tmp = ""
 	parsing_number = False
 	symbols_dic = {}  # Dictionary to keep track of the no. of times each variable appears.
@@ -114,22 +115,6 @@ def peek_list(tokens):
         return tokens[-1]
     else:
         raise IndexError("The token list is empty.", tokens)
-
-def replace_variables(tokens, new_constants):
-	# Searches and replaces variable Tokens with Constant TokenType Token objects. Doing so enables the calc_engine to never have
-	# to even know variable token types exist.
-	# Returns a list of Token objects with the variables replaced by the supplied list of new constants.
-	newTokenList = []
-	for t in tokens:
-		if t.type == token.TokenType.variable:
-			if not t.is_negative_variable:
-				newTokenList.append(token.Token(new_constants.pop(0), token.TokenType.constant))
-			else:
-				newTokenList.append(token.Token(new_constants.pop(0) * -1, token.TokenType.constant))
-		else:
-			newTokenList.append(token.Token(t.value, t.type))
-			
-	return newTokenList
 	
 def print_token_list(tokens):
 	# Prints the list of Tokens to standard out.