Merged revisions 59275-59303 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
NOTE: The merge does NOT contain the modified file Python/import.c from
      r59288. I can't get it running. Nick, please check in the PEP 366
      manually.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

........
  r59279 | georg.brandl | 2007-12-02 19:17:50 +0100 (Sun, 02 Dec 2007) | 2 lines

  Fix a sentence I missed before. Do not merge to 3k.
........
  r59281 | georg.brandl | 2007-12-02 22:58:54 +0100 (Sun, 02 Dec 2007) | 3 lines

  Add documentation for PySys_* functions.
  Written by Charlie Shepherd for GHOP. Also fixes #1245.
........
  r59288 | nick.coghlan | 2007-12-03 13:55:17 +0100 (Mon, 03 Dec 2007) | 1 line

  Implement PEP 366
........
  r59290 | christian.heimes | 2007-12-03 14:47:29 +0100 (Mon, 03 Dec 2007) | 3 lines

  Applied my patch #1455 with some extra fixes for VS 2005
  The new msvc9compiler module supports VS 2005 and VS 2008. I've also fixed build_ext to support PCbuild8 and PCbuild9 and backported my fix for xxmodule.c from py3k. The old code msvccompiler is still in place in case somebody likes to build an extension with VS 2003 or earlier.
  I've also updated the cygwin compiler module for VS 2005 and VS 2008. It works with VS 2005 but I'm unable to test it with VS 2008. We have to wait for a new version of cygwin.
........
  r59291 | christian.heimes | 2007-12-03 14:55:16 +0100 (Mon, 03 Dec 2007) | 1 line

  Added comment to Misc/NEWS for r59290
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  r59292 | christian.heimes | 2007-12-03 15:28:04 +0100 (Mon, 03 Dec 2007) | 1 line

  I followed MA Lemberg's suggestion and added comments to the late initialization of the type slots.
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  r59293 | facundo.batista | 2007-12-03 17:29:52 +0100 (Mon, 03 Dec 2007) | 3 lines


  Speedup and cleaning of __str__.  Thanks Mark Dickinson.
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  r59294 | facundo.batista | 2007-12-03 18:55:00 +0100 (Mon, 03 Dec 2007) | 4 lines


  Faster _fix function, and some reordering for a more elegant
  coding. Thanks Mark Dickinson.
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  r59295 | martin.v.loewis | 2007-12-03 20:20:02 +0100 (Mon, 03 Dec 2007) | 5 lines

  Issue #1727780: Support loading pickles of random.Random objects created
  on 32-bit systems on 64-bit systems, and vice versa. As a consequence
  of the change, Random pickles created by Python 2.6 cannot be loaded
  in Python 2.5.
........
  r59297 | facundo.batista | 2007-12-03 20:49:54 +0100 (Mon, 03 Dec 2007) | 3 lines


  Two small fixes. Issue 1547.
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  r59299 | georg.brandl | 2007-12-03 20:57:02 +0100 (Mon, 03 Dec 2007) | 2 lines

  #1548: fix apostroph placement.
........
  r59300 | christian.heimes | 2007-12-03 21:01:02 +0100 (Mon, 03 Dec 2007) | 3 lines

  Patch #1537 from Chad Austin
  Change GeneratorExit's base class from Exception to BaseException
  (This time I'm applying the patch to the correct sandbox.)
........
  r59302 | georg.brandl | 2007-12-03 21:03:46 +0100 (Mon, 03 Dec 2007) | 3 lines

  Add examples to the xmlrpclib docs.
  Written for GHOP by Josip Dzolonga.
........

1 files changed, 88 insertions, 123 deletions

diff --git a/Lib/decimal.py b/Lib/decimal.py
index 2c97dbd..39ce582 100644
--- a/Lib/decimal.py
+++ b/Lib/decimal.py
@@ -857,81 +857,51 @@ class Decimal(object):
         Captures all of the information in the underlying representation.
         """
 
+        sign = ['', '-'][self._sign]
         if self._is_special:
-            if self._isnan():
-                minus = '-'*self._sign
-                if self._int == '0':
-                    info = ''
-                else:
-                    info = self._int
-                if self._isnan() == 2:
-                    return minus + 'sNaN' + info
-                return minus + 'NaN' + info
-            if self._isinfinity():
-                minus = '-'*self._sign
-                return minus + 'Infinity'
-
-        if context is None:
-            context = getcontext()
-
-        tmp = list(self._int)
-        numdigits = len(self._int)
-        leftdigits = self._exp + numdigits
-        if eng and not self:  # self = 0eX wants 0[.0[0]]eY, not [[0]0]0eY
-            if self._exp < 0 and self._exp >= -6:  # short, no need for e/E
-                s = '-'*self._sign + '0.' + '0'*(abs(self._exp))
-                return s
-            # exp is closest mult. of 3 >= self._exp
-            exp = ((self._exp - 1)// 3 + 1) * 3
-            if exp != self._exp:
-                s = '0.'+'0'*(exp - self._exp)
-            else:
-                s = '0'
-            if exp != 0:
-                if context.capitals:
-                    s += 'E'
-                else:
-                    s += 'e'
-                if exp > 0:
-                    s += '+'  # 0.0e+3, not 0.0e3
-                s += str(exp)
-            s = '-'*self._sign + s
-            return s
-        if eng:
-            dotplace = (leftdigits-1)%3+1
-            adjexp = leftdigits -1 - (leftdigits-1)%3
-        else:
-            adjexp = leftdigits-1
+            if self._exp == 'F':
+                return sign + 'Infinity'
+            elif self._exp == 'n':
+                return sign + 'NaN' + self._int
+            else: # self._exp == 'N'
+                return sign + 'sNaN' + self._int
+
+        # number of digits of self._int to left of decimal point
+        leftdigits = self._exp + len(self._int)
+
+        # dotplace is number of digits of self._int to the left of the
+        # decimal point in the mantissa of the output string (that is,
+        # after adjusting the exponent)
+        if self._exp <= 0 and leftdigits > -6:
+            # no exponent required
+            dotplace = leftdigits
+        elif not eng:
+            # usual scientific notation: 1 digit on left of the point
             dotplace = 1
-        if self._exp == 0:
-            pass
-        elif self._exp < 0 and adjexp >= 0:
-            tmp.insert(leftdigits, '.')
-        elif self._exp < 0 and adjexp >= -6:
-            tmp[0:0] = ['0'] * int(-leftdigits)
-            tmp.insert(0, '0.')
+        elif self._int == '0':
+            # engineering notation, zero
+            dotplace = (leftdigits + 1) % 3 - 1
         else:
-            if numdigits > dotplace:
-                tmp.insert(dotplace, '.')
-            elif numdigits < dotplace:
-                tmp.extend(['0']*(dotplace-numdigits))
-            if adjexp:
-                if not context.capitals:
-                    tmp.append('e')
-                else:
-                    tmp.append('E')
-                    if adjexp > 0:
-                        tmp.append('+')
-                tmp.append(str(adjexp))
-        if eng:
-            while tmp[0:1] == ['0']:
-                tmp[0:1] = []
-            if len(tmp) == 0 or tmp[0] == '.' or tmp[0].lower() == 'e':
-                tmp[0:0] = ['0']
-        if self._sign:
-            tmp.insert(0, '-')
+            # engineering notation, nonzero
+            dotplace = (leftdigits - 1) % 3 + 1
+
+        if dotplace <= 0:
+            intpart = '0'
+            fracpart = '.' + '0'*(-dotplace) + self._int
+        elif dotplace >= len(self._int):
+            intpart = self._int+'0'*(dotplace-len(self._int))
+            fracpart = ''
+        else:
+            intpart = self._int[:dotplace]
+            fracpart = '.' + self._int[dotplace:]
+        if leftdigits == dotplace:
+            exp = ''
+        else:
+            if context is None:
+                context = getcontext()
+            exp = ['e', 'E'][context.capitals] + "%+d" % (leftdigits-dotplace)
 
-        return ''.join(tmp)
+        return sign + intpart + fracpart + exp
 
     def to_eng_string(self, context=None):
         """Convert to engineering-type string.
@@ -1127,29 +1097,6 @@ class Decimal(object):
 
         return other.__sub__(self, context=context)
 
-    def _increment(self):
-        """Special case of add, adding 1eExponent
-
-        Since it is common, (rounding, for example) this adds
-        (sign)*one E self._exp to the number more efficiently than add.
-
-        Assumes that self is nonspecial.
-
-        For example:
-        Decimal('5.624e10')._increment() == Decimal('5.625e10')
-        """
-        L = list(map(int, self._int))
-        L[-1] += 1
-        spot = len(L)-1
-        while L[spot] == 10:
-            L[spot] = 0
-            if spot == 0:
-                L[0:0] = [1]
-                break
-            L[spot-1] += 1
-            spot -= 1
-        return _dec_from_triple(self._sign, "".join(map(str, L)), self._exp)
-
     def __mul__(self, other, context=None):
         """Return self * other.
 
@@ -1580,8 +1527,18 @@ class Decimal(object):
         # round if self has too many digits
         if self._exp < exp_min:
             context._raise_error(Rounded)
-            ans = self._rescale(exp_min, context.rounding)
-            if ans != self:
+            digits = len(self._int) + self._exp - exp_min
+            if digits < 0:
+                self = _dec_from_triple(self._sign, '1', exp_min-1)
+                digits = 0
+            this_function = getattr(self, self._pick_rounding_function[context.rounding])
+            changed = this_function(digits)
+            coeff = self._int[:digits] or '0'
+            if changed == 1:
+                coeff = str(int(coeff)+1)
+            ans = _dec_from_triple(self._sign, coeff, exp_min)
+
+            if changed:
                 context._raise_error(Inexact)
                 if self_is_subnormal:
                     context._raise_error(Underflow)
@@ -1614,66 +1571,68 @@ class Decimal(object):
     # for each of the rounding functions below:
     #   self is a finite, nonzero Decimal
     #   prec is an integer satisfying 0 <= prec < len(self._int)
-    # the rounded result will have exponent self._exp + len(self._int) - prec;
+    #
+    # each function returns either -1, 0, or 1, as follows:
+    #   1 indicates that self should be rounded up (away from zero)
+    #   0 indicates that self should be truncated, and that all the
+    #     digits to be truncated are zeros (so the value is unchanged)
+    #  -1 indicates that there are nonzero digits to be truncated
 
     def _round_down(self, prec):
         """Also known as round-towards-0, truncate."""
-        newexp = self._exp + len(self._int) - prec
-        return _dec_from_triple(self._sign, self._int[:prec] or '0', newexp)
+        if _all_zeros(self._int, prec):
+            return 0
+        else:
+            return -1
 
     def _round_up(self, prec):
         """Rounds away from 0."""
-        newexp = self._exp + len(self._int) - prec
-        tmp = _dec_from_triple(self._sign, self._int[:prec] or '0', newexp)
-        for digit in self._int[prec:]:
-            if digit != '0':
-                return tmp._increment()
-        return tmp
+        return -self._round_down(prec)
 
     def _round_half_up(self, prec):
         """Rounds 5 up (away from 0)"""
         if self._int[prec] in '56789':
-            return self._round_up(prec)
+            return 1
+        elif _all_zeros(self._int, prec):
+            return 0
         else:
-            return self._round_down(prec)
+            return -1
 
     def _round_half_down(self, prec):
         """Round 5 down"""
-        if self._int[prec] == '5':
-            for digit in self._int[prec+1:]:
-                if digit != '0':
-                    break
-            else:
-                return self._round_down(prec)
-        return self._round_half_up(prec)
+        if _exact_half(self._int, prec):
+            return -1
+        else:
+            return self._round_half_up(prec)
 
     def _round_half_even(self, prec):
         """Round 5 to even, rest to nearest."""
-        if prec and self._int[prec-1] in '13579':
-            return self._round_half_up(prec)
+        if _exact_half(self._int, prec) and \
+                (prec == 0 or self._int[prec-1] in '02468'):
+            return -1
         else:
-            return self._round_half_down(prec)
+            return self._round_half_up(prec)
 
     def _round_ceiling(self, prec):
         """Rounds up (not away from 0 if negative.)"""
         if self._sign:
             return self._round_down(prec)
         else:
-            return self._round_up(prec)
+            return -self._round_down(prec)
 
     def _round_floor(self, prec):
         """Rounds down (not towards 0 if negative)"""
         if not self._sign:
             return self._round_down(prec)
         else:
-            return self._round_up(prec)
+            return -self._round_down(prec)
 
     def _round_05up(self, prec):
         """Round down unless digit prec-1 is 0 or 5."""
-        if prec == 0 or self._int[prec-1] in '05':
-            return self._round_up(prec)
-        else:
+        if prec and self._int[prec-1] not in '05':
             return self._round_down(prec)
+        else:
+            return -self._round_down(prec)
 
     def fma(self, other, third, context=None):
         """Fused multiply-add.
@@ -2330,7 +2289,11 @@ class Decimal(object):
             self = _dec_from_triple(self._sign, '1', exp-1)
             digits = 0
         this_function = getattr(self, self._pick_rounding_function[rounding])
-        return this_function(digits)
+        changed = this_function(digits)
+        coeff = self._int[:digits] or '0'
+        if changed == 1:
+            coeff = str(int(coeff)+1)
+        return _dec_from_triple(self._sign, coeff, exp)
 
     def to_integral_exact(self, rounding=None, context=None):
         """Rounds to a nearby integer.
@@ -5236,6 +5199,8 @@ _parser = re.compile(r"""     # A numeric string consists of:
     $
 """, re.VERBOSE | re.IGNORECASE).match
 
+_all_zeros = re.compile('0*$').match
+_exact_half = re.compile('50*$').match
 del re