# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1531774847 -7200
# Node ID 51ba0ae74af25f647ec815b4d8dc700f7fb2a1dd
# Parent  263b43304dca7e737916e58669ea3108451993e3
Added tuple addition support.

diff -r 263b43304dca -r 51ba0ae74af2 lib/__builtins__/tuple.py
--- a/lib/__builtins__/tuple.py	Mon Jul 16 22:20:57 2018 +0200
+++ b/lib/__builtins__/tuple.py	Mon Jul 16 23:00:47 2018 +0200
@@ -3,7 +3,7 @@
 """
 Tuple objects.
 
-Copyright (C) 2015, 2016, 2017 Paul Boddie <paul@boddie.org.uk>
+Copyright (C) 2015, 2016, 2017, 2018 Paul Boddie <paul@boddie.org.uk>
 
 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
@@ -22,7 +22,8 @@
 from __builtins__.iteration.iterator import itemiterator
 from __builtins__.sequence import hashable, sequence
 from native import tuple_init, \
-                   list_element, list_len, list_setsize, list_setelement
+                   list_element, list_len, list_setsize, list_setelement, \
+                   isinstance as _isinstance
 
 class tuple(sequence, hashable):
 
@@ -73,7 +74,13 @@
 
         return list_len(self.__data__)
 
-    def __add__(self, other): pass
+    def __add__(self, other):
+
+        "Add this tuple to 'other'."
+
+        if not _isinstance(other, tuple):
+            raise TypeError
+        return tuple(tuplepair(self, other))
 
     def __str__(self):
 
@@ -110,4 +117,28 @@
 
         raise TypeError
 
+class tuplepair:
+
+    "A combination of tuples."
+
+    def __init__(self, a, b):
+        self.a = a
+        self.b = b
+
+    def __len__(self):
+
+        "Return the combined length of the tuples."
+
+        return len(self.a) + len(self.b)
+
+    def __getitem__(self, index):
+
+        "Return the value from 'index' in the combined tuple."
+
+        asize = len(self.a)
+        if index < asize:
+            return self.a.__get_single_item__(index)
+        else:
+            return self.b.__get_single_item__(index - asize)
+
 # vim: tabstop=4 expandtab shiftwidth=4
diff -r 263b43304dca -r 51ba0ae74af2 tests/tuple.py
--- a/tests/tuple.py	Mon Jul 16 22:20:57 2018 +0200
+++ b/tests/tuple.py	Mon Jul 16 23:00:47 2018 +0200
@@ -31,3 +31,19 @@
     a, b, c = l
 except ValueError, exc:
     print "a, b, c = l: failed with length", exc.value
+
+# Add tuples together.
+
+m = ("five", 6, 7, 8)
+n = t + m
+print n                 # (1, 2, 3, "four", "five", 6, 7, 8)
+
+# Add to list, really testing tuple iteration.
+
+o = l + m
+print o                 # [1, 2, 3, "four", "five", 6, 7, 8]
+
+try:
+    print t + l         # should raise an exception
+except TypeError:
+    print "t + l: failed due to tuple-list addition"