New test_long.py from Tim Peters.

Lib/test/output/test_long

 test_long
 long / * % divmod
 long bit-operation identities
-long str/hex/oct
+long str/hex/oct/atol
+long miscellaneous operations
 

Lib/test/test_long.py

@@ -11,6 +11,20 @@ MASK = BASE - 1
 # this will at least quadruple the runtime.
 MAXDIGITS = 10
 
+# build some special values
+special = map(long, [0, 1, 2, BASE, BASE >> 1])
+special.append(0x5555555555555555L)
+special.append(0xaaaaaaaaaaaaaaaaL)
+#  some solid strings of one bits
+p2 = 4L  # 0 and 1 already added
+for i in range(2*SHIFT):
+    special.append(p2 - 1)
+    p2 = p2 << 1
+del p2
+# add complements & negations
+special = special + map(lambda x: ~x, special) + \
+                    map(lambda x: -x, special)
+
 # ------------------------------------------------------------ utilities
 
 # Use check instead of assert so the test still does something
@@ -20,10 +34,37 @@ def check(ok, *args):
     if not ok:
         raise TestFailed, join(map(str, args), " ")
 
+# Get quasi-random long consisting of ndigits digits (in base BASE).
+# quasi == the most-significant digit will not be 0, and the number
+# is constructed to contain long strings of 0 and 1 bits.  These are
+# more likely than random bits to provoke digit-boundary errors.
+# The sign of the number is also random.
+
+def getran(ndigits):
+    assert ndigits > 0
+    nbits_hi = ndigits * SHIFT
+    nbits_lo = nbits_hi - SHIFT + 1
+    answer = 0L
+    nbits = 0
+    r = int(random() * (SHIFT * 2)) | 1  # force 1 bits to start
+    while nbits < nbits_lo:
+        bits = (r >> 1) + 1
+        bits = min(bits, nbits_hi - nbits)
+        assert 1 <= bits <= SHIFT
+        nbits = nbits + bits
+        answer = answer << bits
+        if r & 1:
+            answer = answer | ((1 << bits) - 1)
+        r = int(random() * (SHIFT * 2))
+    assert nbits_lo <= nbits <= nbits_hi
+    if random() < 0.5:
+        answer = -answer
+    return answer
+
 # Get random long consisting of ndigits random digits (relative to base
 # BASE).  The sign bit is also random.
 
-def getran(ndigits):
+def getran2(ndigits):
     answer = 0L
     for i in range(ndigits):
         answer = (answer << SHIFT) | randint(0, MASK)
@@ -56,6 +97,12 @@ def test_division(maxdigits=MAXDIGITS):
 # -------------------------------------------------------------- ~ & | ^
 
 def test_bitop_identities_1(x):
+    check(x & 0 == 0, "x & 0 != 0 for", x)
+    check(x | 0 == x, "x | 0 != x for", x)
+    check(x ^ 0 == x, "x ^ 0 != x for", x)
+    check(x & -1 == x, "x & -1 != x for", x)
+    check(x | -1 == -1, "x | -1 != -1 for", x)
+    check(x ^ -1 == ~x, "x ^ -1 != ~x for", x)
     check(x == ~~x, "x != ~~x for", x)
     check(x & x == x, "x & x != x for", x)
     check(x | x == x, "x | x != x for", x)
@@ -63,13 +110,21 @@ def test_bitop_identities_1(x):
     check(x & ~x == 0, "x & ~x != 0 for", x)
     check(x | ~x == -1, "x | ~x != -1 for", x)
     check(x ^ ~x == -1, "x ^ ~x != -1 for", x)
-    check(-x == 1 + ~x, "-x != 1 + ~x for", x)
-    for s in range(2*SHIFT):
-        check( ((x >> s) << s) | (x & ((1L << s) - 1)) == x,
-              "((x >> s) << s) | (x & ((1L << s) - 1)) != x for",
-                x, s)
+    check(-x == 1 + ~x == ~(x-1), "not -x == 1 + ~x == ~(x-1) for", x)
+    for n in range(2*SHIFT):
+        p2 = 2L ** n
+        check(x << n >> n == x, "x << n >> n != x for", x, n)
+        check(x / p2 == x >> n, "x / p2 != x >> n for x n p2", x, n, p2)
+        check(x * p2 == x << n, "x * p2 != x << n for x n p2", x, n, p2)
+        check(x & -p2 == x >> n << n == x & ~(p2 - 1),
+            "not x & -p2 == x >> n << n == x & ~(p2 - 1) for x n p2",
+            x, n, p2)
 
 def test_bitop_identities_2(x, y):
+    check(x & y == y & x, "x & y != y & x for", x, y)
+    check(x | y == y | x, "x | y != y | x for", x, y)
+    check(x ^ y == y ^ x, "x ^ y != y ^ x for", x, y)
+    check(x ^ y ^ x == y, "x ^ y ^ x != y for", x, y)
     check(x & y == ~(~x | ~y), "x & y != ~(~x | ~y) for", x, y)
     check(x | y == ~(~x & ~y), "x | y != ~(~x & ~y) for", x, y)
     check(x ^ y == (x | y) & ~(x & y),
@@ -80,6 +135,12 @@ def test_bitop_identities_2(x, y):
          "x ^ y == (x | y) & (~x | ~y) for", x, y)
 
 def test_bitop_identities_3(x, y, z):
+    check((x & y) & z == x & (y & z),
+         "(x & y) & z != x & (y & z) for", x, y, z)
+    check((x | y) | z == x | (y | z),
+         "(x | y) | z != x | (y | z) for", x, y, z)
+    check((x ^ y) ^ z == x ^ (y ^ z),
+         "(x ^ y) ^ z != x ^ (y ^ z) for", x, y, z)
     check(x & (y | z) == (x & y) | (x & z),
          "x & (y | z) != (x & y) | (x & z) for", x, y, z)
     check(x | (y & z) == (x | y) & (x | z),
@@ -87,6 +148,8 @@ def test_bitop_identities_3(x, y, z):
 
 def test_bitop_identities(maxdigits=MAXDIGITS):
     print "long bit-operation identities"
+    for x in special:
+        test_bitop_identities_1(x)
     digits = range(1, maxdigits+1)
     for lenx in digits:
         x = getran(lenx)
@@ -96,7 +159,7 @@ def test_bitop_identities(maxdigits=MAXDIGITS):
             test_bitop_identities_2(x, y)
             test_bitop_identities_3(x, y, getran((lenx + leny)/2))
 
-# ---------------------------------------------------------- hex oct str
+# ------------------------------------------------------ hex oct str atol
 
 def slow_format(x, base):
     if (x, base) == (0, 8):
@@ -106,34 +169,84 @@ def slow_format(x, base):
     sign = 0
     if x < 0:
         sign, x = 1, -x
-    marks = "0123456789ABCDEF"
     while x:
         x, r = divmod(x, base)
         digits.append(int(r))
     digits.reverse()
     digits = digits or [0]
-    return ['', '-'][sign] + \
+    return '-'[:sign] + \
            {8: '0', 10: '', 16: '0x'}[base] + \
-           join(map(lambda i, marks=marks: marks[i], digits), '') + \
+           join(map(lambda i: "0123456789ABCDEF"[i], digits), '') + \
            "L"
 
 def test_format_1(x):
+    from string import atol
     for base, mapper in (8, oct), (10, str), (16, hex):
         got = mapper(x)
         expected = slow_format(x, base)
         check(got == expected, mapper.__name__, "returned",
               got, "but expected", expected, "for", x)
+        check(atol(got, 0) == x, 'atol("%s", 0) !=' % got, x)
 
 def test_format(maxdigits=MAXDIGITS):
-    print "long str/hex/oct"
+    print "long str/hex/oct/atol"
+    for x in special:
+        test_format_1(x)
     for i in range(10):
         for lenx in range(1, maxdigits+1):
             x = getran(lenx)
             test_format_1(x)
 
+# ----------------------------------------------------------------- misc
+
+def test_misc(maxdigits=MAXDIGITS):
+    print "long miscellaneous operations"
+    import sys
+
+    # check the extremes in int<->long conversion
+    hugepos = sys.maxint
+    hugeneg = -hugepos - 1
+    hugepos_aslong = long(hugepos)
+    hugeneg_aslong = long(hugeneg)
+    check(hugepos == hugepos_aslong, "long(sys.maxint) != sys.maxint")
+    check(hugeneg == hugeneg_aslong,
+        "long(-sys.maxint-1) != -sys.maxint-1")
+
+    # long -> int should not fail for hugepos_aslong or hugeneg_aslong
+    try:
+        check(int(hugepos_aslong) == hugepos,
+              "converting sys.maxint to long and back to int fails")
+    except OverflowError:
+        raise TestFailed, "int(long(sys.maxint)) overflowed!"
+    try:
+        check(int(hugeneg_aslong) == hugeneg,
+              "converting -sys.maxint-1 to long and back to int fails")
+    except OverflowError:
+        raise TestFailed, "int(long(-sys.maxint-1)) overflowed!"
+
+    # but long -> int should overflow for hugepos+1 and hugeneg-1
+    x = hugepos_aslong + 1
+    try:
+        int(x)
+        raise ValueError
+    except OverflowError:
+        pass
+    except:
+        raise TestFailed, "int(long(sys.maxint) + 1) didn't overflow"
+
+    x = hugeneg_aslong - 1
+    try:
+        int(x)
+        raise ValueError
+    except OverflowError:
+        pass
+    except:
+        raise TestFailed, "int(long(-sys.maxint-1) - 1) didn't overflow"
+
 # ---------------------------------------------------------------- do it
 
 test_division()
 test_bitop_identities()
 test_format()
+test_misc()