ExprRef Class Reference

Expressions. More...

Inheritance diagram for ExprRef:

Public Member Functions
	as_ast (self)
	get_id (self)
	sort (self)
	sort_kind (self)
	__eq__ (self, other)
	__hash__ (self)
	__ne__ (self, other)
	params (self)
	decl (self)
	kind (self)
	num_args (self)
	arg (self, idx)
	children (self)
	update (self, *args)
	from_string (self, s)
	serialize (self)
Public Member Functions inherited from AstRef
	__init__ (self, ast, ctx=None)
	__del__ (self)
	__deepcopy__ (self, memo={})
	__str__ (self)
	__repr__ (self)
	__eq__ (self, other)
	__hash__ (self)
	__nonzero__ (self)
	__bool__ (self)
	sexpr (self)
	ctx_ref (self)
	eq (self, other)
	translate (self, target)
	__copy__ (self)
	hash (self)
	py_value (self)
Public Member Functions inherited from Z3PPObject
	use_pp (self)

Additional Inherited Members
Data Fields inherited from AstRef
	ast = ast
	ctx = _get_ctx(ctx)
Protected Member Functions inherited from Z3PPObject
	_repr_html_ (self)

Detailed Description

Expressions.

Constraints, formulas and terms are expressions in Z3.

Expressions are ASTs. Every expression has a sort.
There are three main kinds of expressions:
function applications, quantifiers and bounded variables.
A constant is a function application with 0 arguments.
For quantifier free problems, all expressions are
function applications.

Definition at line 1018 of file z3py.py.

Member Function Documentation

__eq__()

__eq__	(		self,
			other )

Return a Z3 expression that represents the constraint `self == other`.

If `other` is `None`, then this method simply returns `False`.

>>> a = Int('a')
>>> b = Int('b')
>>> a == b
a == b
>>> a is None
False

Definition at line 1058 of file z3py.py.

    def __eq__(self, other):
        """Return a Z3 expression that represents the constraint `self == other`.
 
        If `other` is `None`, then this method simply returns `False`.
 
        >>> a = Int('a')
        >>> b = Int('b')
        >>> a == b
        a == b
        >>> a is None
        False
        """
        if other is None:
            return False
        a, b = _coerce_exprs(self, other)
        return BoolRef(Z3_mk_eq(self.ctx_ref(), a.as_ast(), b.as_ast()), self.ctx)
 

Referenced by CheckSatResult.__ne__().

__hash__()

__hash__

(

self

)

Hash code. 

Definition at line 1075 of file z3py.py.

    def __hash__(self):
        """ Hash code. """
        return AstRef.__hash__(self)
 

__ne__()

__ne__	(		self,
			other )

Return a Z3 expression that represents the constraint `self != other`.

If `other` is `None`, then this method simply returns `True`.

>>> a = Int('a')
>>> b = Int('b')
>>> a != b
a != b
>>> a is not None
True

Definition at line 1079 of file z3py.py.

    def __ne__(self, other):
        """Return a Z3 expression that represents the constraint `self != other`.
 
        If `other` is `None`, then this method simply returns `True`.
 
        >>> a = Int('a')
        >>> b = Int('b')
        >>> a != b
        a != b
        >>> a is not None
        True
        """
        if other is None:
            return True
        a, b = _coerce_exprs(self, other)
        _args, sz = _to_ast_array((a, b))
        return BoolRef(Z3_mk_distinct(self.ctx_ref(), 2, _args), self.ctx)
 

arg()

arg	(		self,
			idx )

Return argument `idx` of the application `self`.

This method assumes that `self` is a function application with at least `idx+1` arguments.

>>> a = Int('a')
>>> b = Int('b')
>>> f = Function('f', IntSort(), IntSort(), IntSort(), IntSort())
>>> t = f(a, b, 0)
>>> t.arg(0)
a
>>> t.arg(1)
b
>>> t.arg(2)
0

Definition at line 1138 of file z3py.py.

    def arg(self, idx):
        """Return argument `idx` of the application `self`.
 
        This method assumes that `self` is a function application with at least `idx+1` arguments.
 
        >>> a = Int('a')
        >>> b = Int('b')
        >>> f = Function('f', IntSort(), IntSort(), IntSort(), IntSort())
        >>> t = f(a, b, 0)
        >>> t.arg(0)
        a
        >>> t.arg(1)
        b
        >>> t.arg(2)
        0
        """
        if z3_debug():
            _z3_assert(is_app(self), "Z3 application expected")
            _z3_assert(idx < self.num_args(), "Invalid argument index")
        return _to_expr_ref(Z3_get_app_arg(self.ctx_ref(), self.as_ast(), idx), self.ctx)
 

Referenced by AstRef.__bool__(), and children().

as_ast()

as_ast

(

self

)

Return a pointer to the corresponding C Z3_ast object.

Reimplemented from AstRef.

Reimplemented in PatternRef, and QuantifierRef.

Definition at line 1029 of file z3py.py.

    def as_ast(self):
        return self.ast
 

Referenced by update().

children()

children

(

self

)

Return a list containing the children of the given expression

>>> a = Int('a')
>>> b = Int('b')
>>> f = Function('f', IntSort(), IntSort(), IntSort(), IntSort())
>>> t = f(a, b, 0)
>>> t.children()
[a, b, 0]

Reimplemented in QuantifierRef.

Definition at line 1159 of file z3py.py.

    def children(self):
        """Return a list containing the children of the given expression
 
        >>> a = Int('a')
        >>> b = Int('b')
        >>> f = Function('f', IntSort(), IntSort(), IntSort(), IntSort())
        >>> t = f(a, b, 0)
        >>> t.children()
        [a, b, 0]
        """
        if is_app(self):
            return [self.arg(i) for i in range(self.num_args())]
        else:
            return []
 

decl()

decl

(

self

)

Return the Z3 function declaration associated with a Z3 application.

>>> f = Function('f', IntSort(), IntSort())
>>> a = Int('a')
>>> t = f(a)
>>> eq(t.decl(), f)
True
>>> (a + 1).decl()
+

Definition at line 1100 of file z3py.py.

    def decl(self):
        """Return the Z3 function declaration associated with a Z3 application.
 
        >>> f = Function('f', IntSort(), IntSort())
        >>> a = Int('a')
        >>> t = f(a)
        >>> eq(t.decl(), f)
        True
        >>> (a + 1).decl()
        +
        """
        if z3_debug():
            _z3_assert(is_app(self), "Z3 application expected")
        return FuncDeclRef(Z3_get_app_decl(self.ctx_ref(), self.as_ast()), self.ctx)
 

Referenced by params().

from_string()

from_string	(		self,
			s )

Definition at line 1198 of file z3py.py.

    def from_string(self, s):
        pass
 

get_id()

get_id

(

self

)

Return unique identifier for object. It can be used for hash-tables and maps.

Reimplemented from AstRef.

Reimplemented in PatternRef, and QuantifierRef.

Definition at line 1032 of file z3py.py.

    def get_id(self):
        return Z3_get_ast_id(self.ctx_ref(), self.as_ast())
 

kind()

kind

(

self

)

Return the Z3 internal kind of a function application.

Definition at line 1115 of file z3py.py.

    def kind(self):
        """Return the Z3 internal kind of a function application."""
        if z3_debug():
            _z3_assert(is_app(self), "Z3 application expected")
        return Z3_get_decl_kind(self.ctx_ref(), Z3_get_app_decl(self.ctx_ref(), self.ast))
        
 

Referenced by sort_kind().

num_args()

num_args

(

self

)

Return the number of arguments of a Z3 application.

>>> a = Int('a')
>>> b = Int('b')
>>> (a + b).num_args()
2
>>> f = Function('f', IntSort(), IntSort(), IntSort(), IntSort())
>>> t = f(a, b, 0)
>>> t.num_args()
3

Definition at line 1122 of file z3py.py.

    def num_args(self):
        """Return the number of arguments of a Z3 application.
 
        >>> a = Int('a')
        >>> b = Int('b')
        >>> (a + b).num_args()
        2
        >>> f = Function('f', IntSort(), IntSort(), IntSort(), IntSort())
        >>> t = f(a, b, 0)
        >>> t.num_args()
        3
        """
        if z3_debug():
            _z3_assert(is_app(self), "Z3 application expected")
        return int(Z3_get_app_num_args(self.ctx_ref(), self.as_ast()))
 

Referenced by AstRef.__bool__(), arg(), FuncEntry.arg_value(), FuncEntry.as_list(), children(), and update().

params()

params

(

self

)

Definition at line 1097 of file z3py.py.

    def params(self):
        return self.decl().params()
 

Referenced by params().

serialize()

serialize

(

self

)

Definition at line 1201 of file z3py.py.

    def serialize(self):
        s = Solver()
        f = Function('F', self.sort(), BoolSort(self.ctx))
        s.add(f(self))
        return s.sexpr()
 

sort()

sort

(

self

)

Return the sort of expression `self`.

>>> x = Int('x')
>>> (x + 1).sort()
Int
>>> y = Real('y')
>>> (x + y).sort()
Real

Reimplemented in ArithRef, ArrayRef, BitVecRef, BoolRef, DatatypeRef, FiniteDomainRef, FPRef, QuantifierRef, and SeqRef.

Definition at line 1035 of file z3py.py.

    def sort(self):
        """Return the sort of expression `self`.
 
        >>> x = Int('x')
        >>> (x + 1).sort()
        Int
        >>> y = Real('y')
        >>> (x + y).sort()
        Real
        """
        return _sort(self.ctx, self.as_ast())
 

Referenced by ArrayRef.domain(), ArrayRef.domain_n(), ArithRef.is_int(), ArithRef.is_real(), ArrayRef.range(), BitVecRef.size(), and sort_kind().

sort_kind()

sort_kind

(

self

)

Shorthand for `self.sort().kind()`.

>>> a = Array('a', IntSort(), IntSort())
>>> a.sort_kind() == Z3_ARRAY_SORT
True
>>> a.sort_kind() == Z3_INT_SORT
False

Definition at line 1047 of file z3py.py.

    def sort_kind(self):
        """Shorthand for `self.sort().kind()`.
 
        >>> a = Array('a', IntSort(), IntSort())
        >>> a.sort_kind() == Z3_ARRAY_SORT
        True
        >>> a.sort_kind() == Z3_INT_SORT
        False
        """
        return self.sort().kind()
 

update()

update	(		self,
		*	args )

Update the arguments of the expression.

Return a new expression with the same function declaration and updated arguments.
The number of new arguments must match the current number of arguments.

>>> f = Function('f', IntSort(), IntSort(), IntSort())
>>> a = Int('a')
>>> b = Int('b')
>>> c = Int('c')
>>> t = f(a, b)
>>> t.update(c, c)
f(c, c)

Definition at line 1174 of file z3py.py.

    def update(self, *args):
        """Update the arguments of the expression.
        
        Return a new expression with the same function declaration and updated arguments.
        The number of new arguments must match the current number of arguments.
        
        >>> f = Function('f', IntSort(), IntSort(), IntSort())
        >>> a = Int('a')
        >>> b = Int('b')
        >>> c = Int('c')
        >>> t = f(a, b)
        >>> t.update(c, c)
        f(c, c)
        """
        if z3_debug():
            _z3_assert(is_app(self), "Z3 application expected")
            _z3_assert(len(args) == self.num_args(), "Number of arguments does not match")
            _z3_assert(all([is_expr(arg) for arg in args]), "Z3 expressions expected")
        num = len(args)
        _args = (Ast * num)()
        for i in range(num):
            _args[i] = args[i].as_ast()
        return _to_expr_ref(Z3_update_term(self.ctx_ref(), self.as_ast(), num, _args), self.ctx)