Added rudimentary type analysis.

term.py

@@ -39,10 +39,13 @@ def lex(text):
             break
         elif c in "0123456789":
             s = ""
-            while c != END and c in "0123456789":
+            vtype = int
+            while c != END and c in "0123456789.":
                 s+=c
+                if(c == "."):
+                    vtype = float
                 c = next(it,END)
-            yield NumToken(int(s))
+            yield NumToken(vtype(s))
             continue
         elif c == "+":
             yield AddOpToken()
@@ -67,6 +70,7 @@ class OperatorNode:
     def __init__(self, left, right):
         self.left = left
         self.right = right
+        self.vtype = None
 
     def calculate(self):
         raise Exception("Not implemented")
@@ -79,6 +83,16 @@ class OperatorNode:
         print("\t"*tab,self.operator)
         self.right.printAST(tab+1)
 
+    def getType(self):
+        if self.vtype is None:
+            vlefttype = self.left.getType()
+            vrighttype = self.left.getType()
+            if vrighttype == float or vlefttype == float:
+                self.vtype = float
+            else:
+                self.vtype = int
+        return self.vtype
+
 class AdditionNode(OperatorNode):
     operator = "+"
     def calculate(self):
@@ -115,6 +129,12 @@ class NumNode:
     def printAST(self,tab=0):
         print("\t"*tab,self.value)
 
+    def getType(self):
+        if(type(self.value) == int):
+            return int
+        else:
+            return float
+
 # 1. S -> E
 # 2. E -> E+T
 # 3. E -> E-T
@@ -284,5 +304,6 @@ if __name__ == '__main__':
     print(list(lex(l)))
     ast = parse(l)
     ast.printAST()
+    print("Result is of type: %s" % (repr(ast.getType())))
     print(l," = ",ast.calculate())