add hg and python

1 files changed, 310 insertions, 0 deletions

diff --git a/sys/src/cmd/python/Demo/classes/Rat.py b/sys/src/cmd/python/Demo/classes/Rat.py
new file mode 100755
index 000000000..55543b6d2
--- /dev/null
+++ b/sys/src/cmd/python/Demo/classes/Rat.py
@@ -0,0 +1,310 @@
+'''\
+This module implements rational numbers.
+
+The entry point of this module is the function
+        rat(numerator, denominator)
+If either numerator or denominator is of an integral or rational type,
+the result is a rational number, else, the result is the simplest of
+the types float and complex which can hold numerator/denominator.
+If denominator is omitted, it defaults to 1.
+Rational numbers can be used in calculations with any other numeric
+type.  The result of the calculation will be rational if possible.
+
+There is also a test function with calling sequence
+        test()
+The documentation string of the test function contains the expected
+output.
+'''
+
+# Contributed by Sjoerd Mullender
+
+from types import *
+
+def gcd(a, b):
+    '''Calculate the Greatest Common Divisor.'''
+    while b:
+        a, b = b, a%b
+    return a
+
+def rat(num, den = 1):
+    # must check complex before float
+    if isinstance(num, complex) or isinstance(den, complex):
+        # numerator or denominator is complex: return a complex
+        return complex(num) / complex(den)
+    if isinstance(num, float) or isinstance(den, float):
+        # numerator or denominator is float: return a float
+        return float(num) / float(den)
+    # otherwise return a rational
+    return Rat(num, den)
+
+class Rat:
+    '''This class implements rational numbers.'''
+
+    def __init__(self, num, den = 1):
+        if den == 0:
+            raise ZeroDivisionError, 'rat(x, 0)'
+
+        # normalize
+
+        # must check complex before float
+        if (isinstance(num, complex) or
+            isinstance(den, complex)):
+            # numerator or denominator is complex:
+            # normalized form has denominator == 1+0j
+            self.__num = complex(num) / complex(den)
+            self.__den = complex(1)
+            return
+        if isinstance(num, float) or isinstance(den, float):
+            # numerator or denominator is float:
+            # normalized form has denominator == 1.0
+            self.__num = float(num) / float(den)
+            self.__den = 1.0
+            return
+        if (isinstance(num, self.__class__) or
+            isinstance(den, self.__class__)):
+            # numerator or denominator is rational
+            new = num / den
+            if not isinstance(new, self.__class__):
+                self.__num = new
+                if isinstance(new, complex):
+                    self.__den = complex(1)
+                else:
+                    self.__den = 1.0
+            else:
+                self.__num = new.__num
+                self.__den = new.__den
+        else:
+            # make sure numerator and denominator don't
+            # have common factors
+            # this also makes sure that denominator > 0
+            g = gcd(num, den)
+            self.__num = num / g
+            self.__den = den / g
+        # try making numerator and denominator of IntType if they fit
+        try:
+            numi = int(self.__num)
+            deni = int(self.__den)
+        except (OverflowError, TypeError):
+            pass
+        else:
+            if self.__num == numi and self.__den == deni:
+                self.__num = numi
+                self.__den = deni
+
+    def __repr__(self):
+        return 'Rat(%s,%s)' % (self.__num, self.__den)
+
+    def __str__(self):
+        if self.__den == 1:
+            return str(self.__num)
+        else:
+            return '(%s/%s)' % (str(self.__num), str(self.__den))
+
+    # a + b
+    def __add__(a, b):
+        try:
+            return rat(a.__num * b.__den + b.__num * a.__den,
+                       a.__den * b.__den)
+        except OverflowError:
+            return rat(long(a.__num) * long(b.__den) +
+                       long(b.__num) * long(a.__den),
+                       long(a.__den) * long(b.__den))
+
+    def __radd__(b, a):
+        return Rat(a) + b
+
+    # a - b
+    def __sub__(a, b):
+        try:
+            return rat(a.__num * b.__den - b.__num * a.__den,
+                       a.__den * b.__den)
+        except OverflowError:
+            return rat(long(a.__num) * long(b.__den) -
+                       long(b.__num) * long(a.__den),
+                       long(a.__den) * long(b.__den))
+
+    def __rsub__(b, a):
+        return Rat(a) - b
+
+    # a * b
+    def __mul__(a, b):
+        try:
+            return rat(a.__num * b.__num, a.__den * b.__den)
+        except OverflowError:
+            return rat(long(a.__num) * long(b.__num),
+                       long(a.__den) * long(b.__den))
+
+    def __rmul__(b, a):
+        return Rat(a) * b
+
+    # a / b
+    def __div__(a, b):
+        try:
+            return rat(a.__num * b.__den, a.__den * b.__num)
+        except OverflowError:
+            return rat(long(a.__num) * long(b.__den),
+                       long(a.__den) * long(b.__num))
+
+    def __rdiv__(b, a):
+        return Rat(a) / b
+
+    # a % b
+    def __mod__(a, b):
+        div = a / b
+        try:
+            div = int(div)
+        except OverflowError:
+            div = long(div)
+        return a - b * div
+
+    def __rmod__(b, a):
+        return Rat(a) % b
+
+    # a ** b
+    def __pow__(a, b):
+        if b.__den != 1:
+            if isinstance(a.__num, complex):
+                a = complex(a)
+            else:
+                a = float(a)
+            if isinstance(b.__num, complex):
+                b = complex(b)
+            else:
+                b = float(b)
+            return a ** b
+        try:
+            return rat(a.__num ** b.__num, a.__den ** b.__num)
+        except OverflowError:
+            return rat(long(a.__num) ** b.__num,
+                       long(a.__den) ** b.__num)
+
+    def __rpow__(b, a):
+        return Rat(a) ** b
+
+    # -a
+    def __neg__(a):
+        try:
+            return rat(-a.__num, a.__den)
+        except OverflowError:
+            # a.__num == sys.maxint
+            return rat(-long(a.__num), a.__den)
+
+    # abs(a)
+    def __abs__(a):
+        return rat(abs(a.__num), a.__den)
+
+    # int(a)
+    def __int__(a):
+        return int(a.__num / a.__den)
+
+    # long(a)
+    def __long__(a):
+        return long(a.__num) / long(a.__den)
+
+    # float(a)
+    def __float__(a):
+        return float(a.__num) / float(a.__den)
+
+    # complex(a)
+    def __complex__(a):
+        return complex(a.__num) / complex(a.__den)
+
+    # cmp(a,b)
+    def __cmp__(a, b):
+        diff = Rat(a - b)
+        if diff.__num < 0:
+            return -1
+        elif diff.__num > 0:
+            return 1
+        else:
+            return 0
+
+    def __rcmp__(b, a):
+        return cmp(Rat(a), b)
+
+    # a != 0
+    def __nonzero__(a):
+        return a.__num != 0
+
+    # coercion
+    def __coerce__(a, b):
+        return a, Rat(b)
+
+def test():
+    '''\
+    Test function for rat module.
+
+    The expected output is (module some differences in floating
+    precission):
+    -1
+    -1
+    0 0L 0.1 (0.1+0j)
+    [Rat(1,2), Rat(-3,10), Rat(1,25), Rat(1,4)]
+    [Rat(-3,10), Rat(1,25), Rat(1,4), Rat(1,2)]
+    0
+    (11/10)
+    (11/10)
+    1.1
+    OK
+    2 1.5 (3/2) (1.5+1.5j) (15707963/5000000)
+    2 2 2.0 (2+0j)
+
+    4 0 4 1 4 0
+    3.5 0.5 3.0 1.33333333333 2.82842712475 1
+    (7/2) (1/2) 3 (4/3) 2.82842712475 1
+    (3.5+1.5j) (0.5-1.5j) (3+3j) (0.666666666667-0.666666666667j) (1.43248815986+2.43884761145j) 1
+    1.5 1 1.5 (1.5+0j)
+
+    3.5 -0.5 3.0 0.75 2.25 -1
+    3.0 0.0 2.25 1.0 1.83711730709 0
+    3.0 0.0 2.25 1.0 1.83711730709 1
+    (3+1.5j) -1.5j (2.25+2.25j) (0.5-0.5j) (1.50768393746+1.04970907623j) -1
+    (3/2) 1 1.5 (1.5+0j)
+
+    (7/2) (-1/2) 3 (3/4) (9/4) -1
+    3.0 0.0 2.25 1.0 1.83711730709 -1
+    3 0 (9/4) 1 1.83711730709 0
+    (3+1.5j) -1.5j (2.25+2.25j) (0.5-0.5j) (1.50768393746+1.04970907623j) -1
+    (1.5+1.5j) (1.5+1.5j)
+
+    (3.5+1.5j) (-0.5+1.5j) (3+3j) (0.75+0.75j) 4.5j -1
+    (3+1.5j) 1.5j (2.25+2.25j) (1+1j) (1.18235814075+2.85446505899j) 1
+    (3+1.5j) 1.5j (2.25+2.25j) (1+1j) (1.18235814075+2.85446505899j) 1
+    (3+3j) 0j 4.5j (1+0j) (-0.638110484918+0.705394566962j) 0
+    '''
+    print rat(-1L, 1)
+    print rat(1, -1)
+    a = rat(1, 10)
+    print int(a), long(a), float(a), complex(a)
+    b = rat(2, 5)
+    l = [a+b, a-b, a*b, a/b]
+    print l
+    l.sort()
+    print l
+    print rat(0, 1)
+    print a+1
+    print a+1L
+    print a+1.0
+    try:
+        print rat(1, 0)
+        raise SystemError, 'should have been ZeroDivisionError'
+    except ZeroDivisionError:
+        print 'OK'
+    print rat(2), rat(1.5), rat(3, 2), rat(1.5+1.5j), rat(31415926,10000000)
+    list = [2, 1.5, rat(3,2), 1.5+1.5j]
+    for i in list:
+        print i,
+        if not isinstance(i, complex):
+            print int(i), float(i),
+        print complex(i)
+        print
+        for j in list:
+            print i + j, i - j, i * j, i / j, i ** j,
+            if not (isinstance(i, complex) or
+                    isinstance(j, complex)):
+                print cmp(i, j)
+            print
+
+
+if __name__ == '__main__':
+    test()