From da6c32255ed4a8e33e99c01986d0922dc1601a2e Mon Sep 17 00:00:00 2001
From: Jan Lindemann <jan@janware.com>
Date: Thu, 27 Jul 2017 16:51:48 +0200
Subject: [PATCH] Make jwutils.algo.Operator a class

This was a namedtuple before, but I couldn't figure out how to ex-/import it
over module boundaries, so I've made it a class.

Signed-off-by: Jan Lindemann <jan@janware.com>
---
 tools/python/jwutils/algo/ShuntingYard.py | 32 ++++++++++++++++-------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/tools/python/jwutils/algo/ShuntingYard.py b/tools/python/jwutils/algo/ShuntingYard.py
index 2242720..6edc5b3 100644
--- a/tools/python/jwutils/algo/ShuntingYard.py
+++ b/tools/python/jwutils/algo/ShuntingYard.py
@@ -1,10 +1,17 @@
 from collections import namedtuple
 import re
 
-Operator = namedtuple("Operator", [ "func", "nargs" , "prec", "assoc" ]) # export
 L, R = 'Left Right'.split()
 ARG, KEYW, LPAREN, RPAREN = 'arg kw ( )'.split()
 
+class Operator: # export
+
+    def __init__(self, func=None, nargs=2, precedence=3, assoc=L):
+        self.func = func
+        self.nargs = nargs
+        self.prec = precedence
+        self.assoc = assoc
+
 class Stack:
 
     def __init__(self, itemlist=[]):
@@ -34,12 +41,17 @@ class ShuntingYard(object): # export
             for k, v in operators.iteritems():
                 self.add_operator(k, v.func, v.nargs, v.prec, v.assoc)
 
-    def token_string():
-        for k, v in self.__ops:
-            buf = ", " + k
-            if v.nargs > 1:
-                buf += "xxx"
+    def token_string(self):
+        r = ""
+        for k, v in self.__ops.iteritems():
+            buf = ", \"" + k
+            if v.nargs == 1:
+                if k[len(k)-1].isalnum():
+                    buf = buf + ' '
+                buf = buf + "xxx"
+            buf = buf + "\""
             r = r + buf
+
         if len(r):
             return r[2:]
 	return r
@@ -87,12 +99,12 @@ class ShuntingYard(object): # export
                 table.append( (token, action, ' '.join(outq), ' '.join(s[0] for s in stack), note) )
             elif toktype == KEYW:
                 val = self.__ops[token]
-                t1, (f1, n1, p1, a1) = token, val
+                t1, op1 = token, val
                 v = t1
                 note = 'Pop ops from stack to output'
                 while stack:
-                    t2, (f2, n2, p2, a2) = stack[-1]
-                    if (a1 == L and p1 <= p2) or (a1 == R and p1 < p2):
+                    t2, op2 = stack[-1]
+                    if (op1.assoc == L and op1.prec <= op2.prec) or (op1.assoc == R and op1.prec < op2.prec):
                         if t1 != RPAREN:
                             if t2 != LPAREN:
                                 stack.pop()
@@ -126,7 +138,7 @@ class ShuntingYard(object): # export
         note = 'Drain stack to output'
         while stack:
             v = ''
-            t2, (f2, n2, p2, a2) = stack[-1]
+            t2, op2 = stack[-1]
             action = '(Pop op)'
             stack.pop()
             outq.append(t2)