diff --git a/tools/python/jwutils/algo/ShuntingYard.py b/tools/python/jwutils/algo/ShuntingYard.py
index f1a5e7f..d30ce90 100644
--- a/tools/python/jwutils/algo/ShuntingYard.py
+++ b/tools/python/jwutils/algo/ShuntingYard.py
@@ -1,8 +1,9 @@
 from collections import namedtuple
 import re
+import shlex
 
 L, R = 'Left Right'.split()
-ARG, KEYW, LPAREN, RPAREN = 'arg kw ( )'.split()
+ARG, KEYW, QUOTED, LPAREN, RPAREN = 'arg kw quoted ( )'.split()
 
 class Operator: # export
 
@@ -36,6 +37,7 @@ class ShuntingYard(object): # export
 
     def __init__(self, operators = None):
         self.do_debug = False
+        #self.do_debug = True
         self.__ops = {}
         if operators is not None:
             for k, v in operators.iteritems():
@@ -74,9 +76,10 @@ class ShuntingYard(object): # export
         regex = regex[1:]
 
         scanner = re.Scanner([
-          (regex,       lambda scanner,token:("kw", token)),
-          (r"[^\s()]+",      lambda scanner,token:("arg", token)),
-          (r"\s+", None), # None == skip token.
+          (regex,       lambda scanner,token:(KEYW,   token)),
+          (r"'[^']*'",  lambda scanner,token:(QUOTED, token[1:-1])),
+          (r"[^\s()]+", lambda scanner,token:(ARG,    token)),
+          (r"\s+",      None), # None == skip token.
         ])
 
         tokens, remainder = scanner.scan(spec)
@@ -87,7 +90,10 @@ class ShuntingYard(object): # export
         return tokens
         r = []
         for e in tokens:
-            r.append(e[1])
+            if e[0] == "quoted":
+                r.append(e[1][1:-1])
+            else:
+                r.append(e[1])
 
         return r
 
@@ -102,10 +108,10 @@ class ShuntingYard(object): # export
         for toktype, token in tokenized:
             self.debug("Checking token", token)
             note = action = ''
-            if toktype == ARG:
+            if toktype in [ ARG, QUOTED ]:
                 action = 'Add arg to output'
                 outq.append(token)
-                table.append( (token, action, ' '.join(outq), ' '.join(s[0] for s in stack), note) )
+                table.append( (token, action, outq, (s[0] for s in stack), note) )
             elif toktype == KEYW:
                 val = self.__ops[token]
                 t1, op1 = token, val
@@ -129,9 +135,9 @@ class ShuntingYard(object): # export
                             else:
                                 stack.pop()
                                 action = '(Pop & discard "(")'
-                                table.append( (v, action, ' '.join(outq), ' '.join(s[0] for s in stack), note) )
+                                table.append( (v, action, outq, (s[0] for s in stack), note) )
                                 break
-                        table.append( (v, action, ' '.join(outq), ' '.join(s[0] for s in stack), note) )
+                        table.append( (v, action, (outq), (s[0] for s in stack), note) )
                         v = note = ''
                     else:
                         note = ''
@@ -143,7 +149,7 @@ class ShuntingYard(object): # export
                     action = 'Push op token to stack'
                 else:
                     action = 'Discard ")"'
-                table.append( (v, action, ' '.join(outq), ' '.join(s[0] for s in stack), note) )
+                table.append( (v, action, (outq), (s[0] for s in stack), note) )
         note = 'Drain stack to output'
         while stack:
             v = ''
@@ -151,7 +157,7 @@ class ShuntingYard(object): # export
             action = '(Pop op)'
             stack.pop()
             outq.append(t2)
-            table.append( (v, action, ' '.join(outq), ' '.join(s[0] for s in stack), note) )
+            table.append( (v, action, outq, (s[0] for s in stack), note) )
             v = note = ''
         if self.do_debug:
             maxcolwidths = [len(max(x, key=len)) for x in zip(*table)]
@@ -159,7 +165,7 @@ class ShuntingYard(object): # export
             print( ' '.join('{cell:^{width}}'.format(width=width, cell=cell) for (width, cell) in zip(maxcolwidths, row)))
             for row in table[1:]:
                 print( ' '.join('{cell:<{width}}'.format(width=width, cell=cell) for (width, cell) in zip(maxcolwidths, row)))
-        return table[-1][2].split()
+        return table[-1][2]
 
     def infix_to_postfix_orig(self, infix):
 
@@ -207,11 +213,12 @@ class ShuntingYard(object): # export
 
     def eval_postfix(self, postfixexpr):
 
+        self.debug("postfix = ", postfixexpr)
         vals = Stack()
 
         for token in postfixexpr:
 
-            self.debug("Checking token %s" % (token))
+            self.debug("Evaluating token %s" % (token))
             if token not in self.__ops.keys():
                 vals.push(token)
                 continue
@@ -234,6 +241,8 @@ class ShuntingYard(object): # export
             return infix
         postfix = self.infix_to_postfix(infix)
         self.debug(infix, "-->", postfix)
+        for token in postfix:
+            self.debug("Token is %s" % (token))
         return self.eval_postfix(postfix)
 
 if __name__ == '__main__':
@@ -321,4 +330,3 @@ if __name__ == '__main__':
 
     r = Matcher(obj).eval("name=hans and (not label~=worst)")
     self.debug("Result =", r)
-