1 files changed, 126 insertions, 0 deletions
diff --git a/sets.py b/sets.py
new file mode 100644
index 0000000..c5cfb88
--- /dev/null
+++ b/sets.py
@@ -0,0 +1,126 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+'''
+sets – The practical way to se set operations on sets of lines in the shell
+
+Copyright © 2012  Mattias Andrée (maandree@kth.se)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+'''
+
+import sys
+
+def print(text = '', end = '\n'):
+    sys.stdout.buffer.write((str(text) + end).encode('utf-8'))
+
+
+class Set():
+    def __init__(self):
+        self.inv = False
+        self.elems = set()
+    
+    def __and__(x, y):
+        if x.inv and y.inv:
+            return ~(~x | ~y)
+        elif y.inv:
+            return x - ~y
+        elif x.inv:
+            return y - ~x
+        else:
+            rc = Set()
+            for e in x.elems:
+                if e in y.elems:
+                    rc.elems.add(e)
+            return rc
+    
+    def __or__(x, y):
+        if x.inv and y.inv:
+            return ~(~x & ~y)
+        elif y.inv:
+            return x | (U - ~y)
+        elif x.inv:
+            return y | (U - ~x)
+        else:
+            rc = Set()
+            for e in x.elems:
+                rc.elems.add(e)
+            for e in y.elems:
+                if e not in rc.elems:
+                    rc.elems.add(e)
+            return rc
+    
+    def __xor__(x, y):
+        return (x | y) - (x & y)
+    
+    def __sub__(x, y):
+        if x.inv and y.inv:
+            return ~y - ~x
+        elif x.inv:
+            return ~(~x | y)
+        else:
+            rc = Set()
+            for e in x.elems:
+                if (e in y.elems) == y.inv:
+                    rc.elems.add(e)
+            return rc
+    
+    def __invert__(x):
+        rc = Set()
+        rc.elems = x.elems
+        rc.inv = not x.inv
+        return rc
+
+
+sets = [Set()]
+next = Set()
+U = Set()
+
+
+try:
+    while True:
+        e = input()
+        if len(e) == 0:
+            if len(next.elems) > 0:
+                sets.append(next)
+                next = Set()
+        else:
+            if e not in next.elems:
+                next.elems.add(e)
+            if e not in U.elems:
+                U.elems.add(e)
+except:
+    pass
+
+if len(next.elems) > 0:
+    sets.append(next)
+
+
+formula = sys.argv[1]
+formula = formula.replace('\\', '-').replace('*', '&').replace('+', '|')
+
+for i in range(0, 10):
+    formula = formula.replace('%i' % i, 'sets[%i]' % i)
+
+formula = formula.replace(']sets[', '')
+
+rc = eval(formula)
+
+if rc.inv:
+    rc = U - rc
+
+for e in rc.elems:
+    print(e)
+
+sys.stdout.buffer.flush()
+