Add islhelper.c library to handle isl constants
[linpy.git] / pypol / linear.py
index 6550e92..be30fad 100644 (file)
@@ -1,9 +1,14 @@
-
 import functools
 import numbers
+import json
+import ctypes, ctypes.util
+from pypol import isl, islhelper
 
 from fractions import Fraction, gcd
 
+libisl = ctypes.CDLL(ctypes.util.find_library('isl'))
+
+libisl.isl_printer_get_str.restype = ctypes.c_char_p
 
 __all__ = [
     'Expression',
@@ -13,6 +18,75 @@ __all__ = [
     'empty', 'universe'
 ]
 
+'''
+def symbolToInt(self):
+     make dictionary of key:value (letter:integer)
+        iterate through the dictionary to find matching symbol
+        return the given integer value
+    d = {'a': 1, 'b': 2, 'c': 3, 'd': 4, 'e': 5, 'f': 6, 'g': 7, 'h': 8, 'i': 6, 'j': 10, 'k': 11, 'l': 12, 'm': 13, 'n': 14,
+         'o': 15, 'p': 16, 'q': 17, 'r': 18, 's': 19, 't': 20, 'u': 21, 'v': 22, 'w': 23, 'x': 24, 'y': 25, 'z': 26}
+    if self in d:
+        num = d.get(self)
+    return num
+'''
+
+ids = {}
+
+def get_ids(co):
+    if co in ids:
+        return ids.get(co)
+    else:
+        idd = len(ids)
+        ids[co] = idd
+        print(ids)
+        return idd
+
+def _polymorphic_method(func):
+    @functools.wraps(func)
+    def wrapper(a, b):
+        if isinstance(b, Expression):
+            return func(a, b)
+        if isinstance(b, numbers.Rational):
+            b = constant(b)
+            return func(a, b)
+        return NotImplemented
+    return wrapper
+
+def _polymorphic_operator(func):
+    # A polymorphic operator should call a polymorphic method, hence we just
+    # have to test the left operand.
+    @functools.wraps(func)
+    def wrapper(a, b):
+        if isinstance(a, numbers.Rational):
+            a = constant(a)
+            return func(a, b)
+        elif isinstance(a, Expression):
+            return func(a, b)
+        raise TypeError('arguments must be linear expressions')
+    return wrapper
+
+class Context:
+
+    __slots__ = ('_ic')
+
+    def __init__(self):
+        self._ic = libisl.isl_ctx_alloc()
+
+    @property
+    def _as_parameter_(self):
+        return self._ic
+
+    #comment out so does not delete itself after being created
+    #def __del__(self):
+    #   libisl.isl_ctx_free(self)
+
+    def __eq__(self, other):
+        if not isinstance(other, Context):
+            return False
+        return self._ic == other._ic
+
+
+
 
 class Expression:
     """
@@ -43,6 +117,7 @@ class Expression:
         self._constant = constant
         return self
 
+
     def symbols(self):
         yield from sorted(self._coefficients)
 
@@ -78,6 +153,12 @@ class Expression:
             yield self.coefficient(symbol)
         yield self.constant
 
+    def values_int(self):
+        for symbol in self.symbols():
+            return self.coefficient(symbol)
+        return int(self.constant)
+
+
     def symbol(self):
         if not self.issymbol():
             raise ValueError('not a symbol: {}'.format(self))
@@ -96,18 +177,7 @@ class Expression:
     def __neg__(self):
         return self * -1
 
-    def _polymorphic(func):
-        @functools.wraps(func)
-        def wrapper(self, other):
-            if isinstance(other, Expression):
-                return func(self, other)
-            if isinstance(other, numbers.Rational):
-                other = Expression(constant=other)
-                return func(self, other)
-            return NotImplemented
-        return wrapper
-
-    @_polymorphic
+    @_polymorphic_method
     def __add__(self, other):
         coefficients = dict(self.coefficients())
         for symbol, coefficient in other.coefficients():
@@ -120,7 +190,7 @@ class Expression:
 
     __radd__ = __add__
 
-    @_polymorphic
+    @_polymorphic_method
     def __sub__(self, other):
         coefficients = dict(self.coefficients())
         for symbol, coefficient in other.coefficients():
@@ -131,9 +201,10 @@ class Expression:
         constant = self.constant - other.constant
         return Expression(coefficients, constant)
 
-    __rsub__ = __sub__
+    def __rsub__(self, other):
+        return -(self - other)
 
-    @_polymorphic
+    @_polymorphic_method
     def __mul__(self, other):
         if other.isconstant():
             coefficients = dict(self.coefficients())
@@ -148,7 +219,7 @@ class Expression:
 
     __rmul__ = __mul__
 
-    @_polymorphic
+    @_polymorphic_method
     def __truediv__(self, other):
         if other.isconstant():
             coefficients = dict(self.coefficients())
@@ -163,7 +234,7 @@ class Expression:
         return NotImplemented
 
     def __rtruediv__(self, other):
-        if isinstance(other, Rational):
+        if isinstance(other, self):
             if self.isconstant():
                 constant = Fraction(other, self.constant)
                 return Expression(constant=constant)
@@ -230,7 +301,7 @@ class Expression:
     def fromstring(cls, string):
         raise NotImplementedError
 
-    @_polymorphic
+    @_polymorphic_method
     def __eq__(self, other):
         # "normal" equality
         # see http://docs.sympy.org/dev/tutorial/gotchas.html#equals-signs
@@ -246,29 +317,32 @@ class Expression:
                 [value.denominator for value in self.values()])
         return self * lcm
 
-    @_polymorphic
+    @_polymorphic_method
     def _eq(self, other):
         return Polyhedron(equalities=[(self - other)._canonify()])
 
-    @_polymorphic
+    @_polymorphic_method
     def __le__(self, other):
         return Polyhedron(inequalities=[(self - other)._canonify()])
 
-    @_polymorphic
+    @_polymorphic_method
     def __lt__(self, other):
         return Polyhedron(inequalities=[(self - other)._canonify() + 1])
 
-    @_polymorphic
+    @_polymorphic_method
     def __ge__(self, other):
         return Polyhedron(inequalities=[(other - self)._canonify()])
 
-    @_polymorphic
+    @_polymorphic_method
     def __gt__(self, other):
         return Polyhedron(inequalities=[(other - self)._canonify() + 1])
 
 
 def constant(numerator=0, denominator=None):
-    return Expression(constant=Fraction(numerator, denominator))
+    if denominator is None and isinstance(numerator, numbers.Rational):
+        return Expression(constant=3)
+    else:
+        return Expression(constant=Fraction(numerator, denominator))
 
 def symbol(name):
     if not isinstance(name, str):
@@ -281,35 +355,23 @@ def symbols(names):
     return (symbol(name) for name in names)
 
 
-def _operator(func):
-    @functools.wraps(func)
-    def wrapper(a, b):
-        if isinstance(a, numbers.Rational):
-            a = constant(a)
-        if isinstance(b, numbers.Rational):
-            b = constant(b)
-        if isinstance(a, Expression) and isinstance(b, Expression):
-            return func(a, b)
-        raise TypeError('arguments must be linear expressions')
-    return wrapper
-
-@_operator
+@_polymorphic_operator
 def eq(a, b):
     return a._eq(b)
 
-@_operator
+@_polymorphic_operator
 def le(a, b):
     return a <= b
 
-@_operator
+@_polymorphic_operator
 def lt(a, b):
     return a < b
 
-@_operator
+@_polymorphic_operator
 def ge(a, b):
     return a >= b
 
-@_operator
+@_polymorphic_operator
 def gt(a, b):
     return a > b
 
@@ -341,7 +403,14 @@ class Polyhedron:
                         raise TypeError('non-integer constraint: '
                                 '{} <= 0'.format(constraint))
                 self._inequalities.append(constraint)
-        return self
+        self._bset = self.to_isl()
+        #print(self._bset)
+        #put this here just to test from isl method
+        #from_isl = self.from_isl(self._bset)
+        #print(from_isl)
+        #rint(self)
+        return self._bset
+
 
     @property
     def equalities(self):
@@ -351,15 +420,27 @@ class Polyhedron:
     def inequalities(self):
         yield from self._inequalities
 
+    @property
+    def constant(self):
+        return self._constant
+
+    def isconstant(self):
+        return len(self._coefficients) == 0
+
+
+    def isempty(self):
+        return bool(libisl.isl_basic_set_is_empty(self._bset))
+
     def constraints(self):
         yield from self.equalities
         yield from self.inequalities
 
+
     def symbols(self):
         s = set()
         for constraint in self.constraints():
             s.update(constraint.symbols)
-        yield from sorted(s)
+            yield from sorted(s)
 
     @property
     def dimension(self):
@@ -367,7 +448,11 @@ class Polyhedron:
 
     def __bool__(self):
         # return false if the polyhedron is empty, true otherwise
-        raise NotImplementedError
+        if self._equalities or self._inequalities:
+            return False
+        else:
+            return True
+
 
     def __contains__(self, value):
         # is the value in the polyhedron?
@@ -376,8 +461,8 @@ class Polyhedron:
     def __eq__(self, other):
         raise NotImplementedError
 
-    def isempty(self):
-        return self == empty
+    def is_empty(self):
+        return
 
     def isuniverse(self):
         return self == universe
@@ -397,6 +482,11 @@ class Polyhedron:
 
     def issuperset(self, other):
         # test whether every element in other is in the polyhedron
+        for value in other:
+            if value == self.constraints():
+                return True
+            else:
+                return False
         raise NotImplementedError
 
     def __ge__(self, other):
@@ -454,7 +544,57 @@ class Polyhedron:
     def fromstring(cls, string):
         raise NotImplementedError
 
+    def to_isl(self):
+        #d = Expression().__dict__  #write expression values to dictionary in form {'_constant': value, '_coefficients': value}
+        d = {'_constant': 2, '_coefficients': {'b':1}}
+        coeff = d.get('_coefficients')
+        num_coefficients = len(coeff)
+        space = libisl.isl_space_set_alloc(Context(), 0, num_coefficients)
+        bset = libisl.isl_basic_set_empty(libisl.isl_space_copy(space))
+        ls = libisl.isl_local_space_from_space(libisl.isl_space_copy(space))
+        ceq = libisl.isl_equality_alloc(libisl.isl_local_space_copy(ls))
+        cin = libisl.isl_inequality_alloc(libisl.isl_local_space_copy(ls))
+        '''if there are equalities/inequalities, take each constant and coefficient and add as a constraint to the basic set
+        need to change the symbols method to a lookup table for the integer value for each letter that could be a symbol'''
+        if self._equalities:
+            if '_constant' in d:
+                value = d.get('_constant')
+                ceq = libisl.isl_constraint_set_constant_si(ceq, value)
+            if '_coefficients' in d:
+                value_co = d.get('_coefficients')
+                for co in value_co:
+                    num = value_co.get(co)
+                    ceq = libisl.isl_constraint_set_coefficient_si(ceq, islhelper.isl_dim_set, get_ids(co), num)
+            bset = libisl.isl_set_add_constraint(bset, ceq)
+
+        if self._inequalities:
+            if '_constant' in d:
+                value = d.get('_constant')
+                cin = libisl.isl_constraint_set_constant_si(cin, value)
+            if '_coefficients' in d:
+                value_co = d.get('_coefficients')
+                for co in value_co:
+                    num = value_co.get(co)
+                    if value_co: #if dictionary not empty add coefficient as to constraint
+                        cin = libisl.isl_constraint_set_coefficient_si(cin, islhelper.isl_dim_set, get_ids(co), num)
+            bset = libisl.isl_set_add_constraint(bset, cin)
+        ip = libisl.isl_printer_to_str(Context()) #create string printer
+        ip = libisl.isl_printer_print_set(ip, bset) #print set to printer
+        string = libisl.isl_printer_get_str(ip)   #get string from printer
+        string = str(string)
+        print(string)
+        return string
+
+
+    def from_isl(self, bset):
+        '''takes basic set in isl form and puts back into python version of polyhedron
+        isl example code gives idl form as:
+            "{[i] : exists (a : i = 2a and i >= 10 and i <= 42)}");'''
+
+        poly = 0
+        return poly
+
+empty = eq(1,1)
 
-empty = le(1, 0)
 
 universe = Polyhedron()