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Constraints

A collection of symbolic constraints used to define a model.

The Constraints object serves as a container for individual Constraint instances. It supports adding constraints programmatically and exporting them for serialization.

Constraints are typically added using add_constraint() or the += operator.

Examples:

>>> from luna_quantum import Constraints, Constraint, Environment, Variable
>>> with Environment():
...     x = Variable("x")
...     c = Constraint(x + 1, 0.0, Comparator.Le)

>>> cs = Constraints()
>>> cs.add_constraint(c)

>>> cs += x >= 1.0

Serialization:

>>> blob = cs.encode()
>>> expr = Constraints.decode(blob)
Notes
  • This class does not check feasibility or enforce satisfaction.
  • Use encode()/decode() to serialize constraints alongside expressions.

__eq__ method descriptor 

__eq__(value) -> bool

Return self==value.

__ge__ method descriptor 

__ge__(value)

Return self>=value.

__getitem__ method descriptor 

__getitem__(key) -> Constraint

Return self[key].

__init__ 

__init__() -> None

__iter__ 

__iter__() -> Iterator[Constraint]

__le__ method descriptor 

__le__(value)

Return self<=value.

__len__ method descriptor 

__len__() -> int

Return len(self).

__repr__ method descriptor 

__repr__() -> str

Return repr(self).

__str__ method descriptor 

__str__() -> str

Return str(self).

add_constraint method descriptor 

add_constraint(constraint: Constraint, name: str | None = None) -> None

Add a constraint to the collection.

Parameters:

Name Type Description Default
constraint Constraint

The constraint to be added.

 required
name str

The name of the constraint to be added.

 None

ctypes method descriptor 

ctypes() -> list[Comparator]

Get all unique constraint types identified using their comparator.

decode builtin 

decode(data: bytes, env: Environment) -> Expression

Deserialize an expression from binary constraint data.

Parameters:

Name Type Description Default
data bytes

Encoded blob from encode().

 required

Returns:

Type Description
Expression

Expression reconstructed from the constraint context.

Raises:

Type Description
DecodeError

If decoding fails due to corruption or incompatibility.

deserialize builtin 

deserialize(data: bytes, env: Environment) -> Expression

Alias for decode().

See decode() for usage.

encode method descriptor 

encode(compress: bool | None = True, level: int | None = 3) -> bytes

Serialize the constraint collection to a binary blob.

Parameters:

Name Type Description Default
compress bool

Whether to compress the result. Default is True.

 True
level int

Compression level (0–9). Default is 3.

 3

Returns:

Type Description
bytes

Encoded representation of the constraints.

Raises:

Type Description
IOError

If serialization fails.

equal_contents method descriptor 

equal_contents(other: Constraints) -> bool

Check whether this constraints has equal contents as other.

Parameters:

Name Type Description Default
other Constraints
required

Returns:

Type Description
bool

get method descriptor 

get(item: int | str) -> Constraint

Get a constraint for its name or index.

remove method descriptor 

remove(item: int | str) -> Constraint

Remove a constraint for its name or index.

serialize method descriptor 

serialize(compress: bool | None = True, level: int | None = 3) -> bytes

Alias for encode().

See encode() for details.