add multiple arithmatic operator and multiple logical operator

rlispy/eval.py

@@ -43,20 +43,69 @@ def foldl(combine, acc, lst):
                 lst[1:]
                 )
 
+#there don't have apply in python3, so I need to define one
+def apply(proc, *args, **kwargs):
+    return proc(*args, **kwargs)
+
+#define multiobjective arithmetic operators here
+def _add(*operands):
+    result = 0
+    for operand in operands:
+        result = result + operand
+    return result
+
+def _sub(*operands):
+    result = 0
+    for operand in operands:
+        if len(operands) > 1 and result == 0:
+            result = operand
+        else: result = result - operand
+    return result
+
+def _mul(*operands):
+    result = 1
+    for operand in operands:
+        result = result * operand
+    return result
+
+def _truediv(*operands):
+    result = 1
+    for operand in operands:
+        #first step in truediv, we need to let the first num in our operands tuple to be our dividend
+        if result == 1:
+            result = operand
+        else: result = result / operand
+        #and if divisor is 0, python will throw appropriate error to us
+    return result
+
+#define multiobjective logical operators here
+def _and(*args):
+    result = True
+    for arg in args:
+        result = result and arg
+    return result
+
+def _or(*args):
+    result = False
+    for arg in args:
+        result = result or arg
+    return result
 # An environment with some Scheme standard procedures."
 def standard_env():
     env = Env()
     env.update(vars(math))
     env.update({
-        '+':op.add, 
-        '-':op.sub, 
-        '*':op.mul, 
-        '/':op.div, 
+        '+':_add, 
+        '-':_sub, 
+        '*':_mul, 
+        '/':_truediv, 
         '>':op.gt,
         '<':op.lt,
         '>=':op.ge,
         '<=':op.le,
         '=':op.eq,
+        'and':_and,
+        'or':_or,
         'abs': abs,
         'append': op.add,
         'apply': apply,

rlispy/lis.py

@@ -19,14 +19,14 @@
 def repl(prompt='Code: '):
     print("Lispy Version 3.0\n Get Coding!\n")
     while True:
-        inpt = raw_input(prompt)
+        inpt = input(prompt)
         try:
             if inpt == "quit": break
             val = eval(parse(inpt))
             if val is not None: 
                 print(schemestr(val))
         except Exception as e:
-                print '%s: %s' % (type(e).__name__, e)
+                print ('%s: %s' % (type(e).__name__, e))
 
 # Convert a Python object back into a Scheme-readable string.
 def schemestr(exp):

rlispy/parse.py

@@ -1,7 +1,7 @@
 # Parsing Module
 
 from __future__ import division
-import re, sys, StringIO
+import re, sys
 
 # A Scheme List is implemented as a Python list
 # A Scheme Number is implemented as a Python int or float