concepts.dm.crow.executors.crow_executor.CrowExecutor#

class CrowExecutor[source]#

Bases: TensorValueExecutorBase

Methods

`check_constraint`(constraint[, state])
`check_eq_constraint`(dtype, x, y, target[, state])
`execute`(expression[, state, ...])	Execute an expression.
`get_bounded_variable`(variable)	Get the value of a bounded variable.
`get_function_implementation`(name)	Get the implementation of a function.
`has_function_implementation`(name)	Check whether the executor has an implementation for a function.
`new_bounded_variables`(bvdict)	A context manager to add additional bounded variables to the executor.
`parse`(string, *[, state, variables])	Parse an expression.
`register_function`(name, func)	Register an implementation for a function to the executor.
`register_function_implementation`(name, func)	Register an implementation for a function.
`retrieve_bounded_variable_by_name`(name)	Retrieve a bounded variable by its name.
`set_parser`(parser)	Set the parser for the executor.
`update_effect_mode`(evaluation_mode[, ...])
`with_bounded_variables`(bvdict)	A context manager to set the bounded variables for the executor.
`with_csp`(csp)	A context manager to temporarily set the CSP of the executor.
`with_sgc`(sgc)	A context manager to temporarily set the SGC of the executor.
`with_state`([state])	A context manager to temporarily set the state of the executor.

Attributes

`bounded_variables`	The bounded variables for the execution.
`csp`	The CSP that describes the constraints in past executions.
`domain`	The domain of the executor.
`effect_action_index`
`effect_update_from_execution`	A context variable indicating whether the current effect should be updated from the execution of the operator.
`effect_update_from_simulation`	A context variable indicating whether the current effect should be updated from simulation, instead of the evaluation of expressions.
`function_implementations`	The implementations of functions, which is a mapping from function names to implementations.
`optimistic_execution`	Whether to execute the expression optimistically (i.e., treat all CSP constraints True).
`parser`	The parser for the domain.
`pyobj_store`	The Python object store.
`sgc`	The SGC (state-goal-constraints) context.
`state`	The state of the executor.
`value_quantizer`	The value quantizer.

__init__(domain, parser=None)[source]#

Initialize a Crow expression executor.

Parameters:

domain (CrowDomain) – the domain of this executor.
parser (ParserBase | None) – the parser to be used. This argument is optional. If provided, the execute function can take strings as input.

__new__(**kwargs)#

check_constraint(constraint, state=None)#

Parameters:

constraint (Constraint)
state (TensorState | None)

check_eq_constraint(dtype, x, y, target, state=None)#

Parameters:

dtype (TensorValueTypeBase)
x (TensorValue)
y (TensorValue)
target (bool)
state (TensorState | None)

Return type:

bool

execute(expression, state=None, bounded_variables=None, csp=None, sgc=None, optimistic_execution=False)[source]#

Execute an expression.

Parameters:

expression (Expression | str) – the expression to execute.
state (TensorState | None) – the state to use. If None, the current state of the executor will be used.
bounded_variables (None | Sequence[Variable] | Dict[str | Variable, str | int | slice | bool | float | Tensor | TensorValue | ObjectConstant | StateObjectReference] | Dict[str, Dict[str, StateObjectReference | slice | TensorValue]]) – the bounded variables to use. If None, the current bounded variables of the executor will be used.
csp (ConstraintSatisfactionProblem | None) – the constraint satisfaction problem to use. If None, the current CSP of the executor will be used.
sgc (CrowSGC | None) – the SGC (state-goal-constraints) context to use. If None, the current SGC context of the executor will be used.
optimistic_execution (bool) – whether to execute the expression optimistically (i.e., treat all CSP constraints True).

Returns:

the TensorValue object.

Return type:

get_bounded_variable(variable)#

Get the value of a bounded variable.

Parameters:: variable (Variable) – the variable.
Returns:: the value of the variable.
Return type:: TensorValue | slice | StateObjectReference

get_function_implementation(name)[source]#

Get the implementation of a function. When the executor does not have an implementation for the function, the implementation of the function in the domain will be returned. If that is also None, a KeyError will be raised.

Parameters:: name (str) – the name of the function.
Returns:: the implementation of the function.
Return type:: CrowPythonFunctionRef

has_function_implementation(name)#

Check whether the executor has an implementation for a function.

Parameters:: name (str) – the name of the function.
Returns:: whether the executor has an implementation for the function.
Return type:: bool

new_bounded_variables(bvdict)#

A context manager to add additional bounded variables to the executor.

Parameters:: bvdict (None | Sequence[Variable] | Dict[str | Variable, str | int | slice | bool | float | Tensor | TensorValue | ObjectConstant | StateObjectReference] | Dict[str, Dict[str, StateObjectReference | slice | TensorValue]]) – the new bounded variables.

parse(string, *, state=None, variables=None)[source]#

Parse an expression.

Parameters:

expression – the expression to parse. When the input is already an expression, it will be returned directly.
string (str | Expression)
state (CrowState | None)
variables (Sequence[Variable] | None)

Returns:

the parsed expression.

Return type:

Expression

register_function(name, func)#

Parameters:

name (str) – the name of the function.
func (Callable) – the implementation of the function.

register_function_implementation(name, func)[source]#

Parameters:

name (str) – the name of the function.
func (Callable | CrowPythonFunctionRef | CrowPythonFunctionCrossRef) – the implementation of the function.

retrieve_bounded_variable_by_name(name)#

Retrieve a bounded variable by its name.

Parameters:: name (str) – the name of the variable.
Returns:: the value of the variable.
Return type:: TensorValue | slice | StateObjectReference

set_parser(parser)#

Set the parser for the executor.

Parameters:: parser (ParserBase) – the parser.

update_effect_mode(evaluation_mode, action_index=None)[source]#

Parameters:

evaluation_mode (CrowFunctionEvaluationMode)
action_index (int | None)

with_bounded_variables(bvdict)#

A context manager to set the bounded variables for the executor.

Parameters:: bvdict (None | Sequence[Variable] | Dict[str | Variable, str | int | slice | bool | float | Tensor | TensorValue | ObjectConstant | StateObjectReference] | Dict[str, Dict[str, StateObjectReference | slice | TensorValue]]) – the bounded variables.

with_csp(csp)[source]#

A context manager to temporarily set the CSP of the executor.

Parameters:: csp (ConstraintSatisfactionProblem | None)

with_sgc(sgc)[source]#

A context manager to temporarily set the SGC of the executor.

Parameters:: sgc (CrowSGC | None)

with_state(state=None)#

A context manager to temporarily set the state of the executor.

Parameters:: state (TensorState | None)

property bounded_variables: Dict[str, Dict[str, StateObjectReference | slice | TensorValue]]#: The bounded variables for the execution. Note that most of the time you should use the get_bounded_variable() method to get values for the bounded variable.

property csp: ConstraintSatisfactionProblem | None#: The CSP that describes the constraints in past executions.

property domain: CrowDomain#: The domain of the executor.

property effect_action_index: int | None#

property effect_update_from_execution: bool#: A context variable indicating whether the current effect should be updated from the execution of the operator.

property effect_update_from_simulation: bool#: A context variable indicating whether the current effect should be updated from simulation, instead of the evaluation of expressions.

property function_implementations: Dict[str, CrowPythonFunctionRef | CrowPythonFunctionCrossRef]#: The implementations of functions, which is a mapping from function names to implementations.

property optimistic_execution: bool#: Whether to execute the expression optimistically (i.e., treat all CSP constraints True).

property parser: ParserBase | None#: The parser for the domain.

property pyobj_store: PyObjectStore#: The Python object store.

property sgc: CrowSGC | None#: The SGC (state-goal-constraints) context.

property state: CrowState#: The state of the executor.

property value_quantizer: ValueQuantizer#: The value quantizer.