FNode

class unified_planning.model.FNode(content: FNodeContent, node_id: int, environment: Environment)

Bases: object

The FNode class represents an expression tree in the unified_planning library.

Since the FNode is immutable and the same expression can be used in more than one expression tree, it is actually a DAG, but the single expression can be seen as a tree for simplicity.

All the expressions are managed by the ExpressionManager in the Environment, so this class should never be instantiated or modified by the user.

get_nary_expression_string(op: str, args: List[FNode]) → str

property node_id: int

Returns the id of this expression.

property node_type: OperatorKind

Returns the OperatorKind that defines the semantic of this expression.

property environment: Environment

Returns the Environment in which this expression exists.

property args: List[FNode]

Returns the subexpressions of this expression.

property type: Type

Returns the Type of this expression.

get_contained_names() → Set[str]

Returns all the names contained in this expression.

arg(idx: int) → FNode

Return the given subexpression at the given position.

Parameters:

idx – The index of the wanted subexpression.

Returns:

The expression at the position idx.

is_constant() → bool

Returns True if the expression is a constant, False otherwise.

constant_value() → bool | int | Fraction

Returns the constant value stored in this expression.

bool_constant_value() → bool

Return constant boolean value stored in this expression.

int_constant_value() → int

Return constant integer value stored in this expression.

real_constant_value() → Fraction

Return constant real value stored in this expression.

fluent() → Fluent

Return the Fluent stored in this expression.

parameter() → Parameter

Return the Parameter stored in this expression.

variable() → Variable

Return the variable of the VariableExp.

variables() → List[Variable]

Return the Variables of the Exists or Forall.

object() → Object

Return the Object stored in this expression.

timing() → Timing

Return the Timing stored in this expression.

agent() → str

Return the name of the Agent stored in this expression.

simplify() → FNode

Returns the simplified version of this expression.

The simplification is done just by constant propagation by the Simplifier

substitute(substitutions: Dict[unified_planning.model.expression.Expression, unified_planning.model.expression.Expression])

Returns the version of this expression where every expression that is a key of the substitutions map is substituted with it’s value in the map.

NOTE: check the Substituter documentation for more details!

Parameters:

substitutions – The mapping of expressions that must be substituted.

Returns:

The expression where every instance of a key value in the substitutions map is substituted with it’s value.

is_bool_constant() → bool

Test whether the expression is a boolean constant.

is_int_constant() → bool

Test whether the expression is an integer constant.

is_real_constant() → bool

Test whether the expression is a real constant.

is_true() → bool

Test whether the expression is the True Boolean constant.

is_false() → bool

Test whether the expression is the False Boolean constant.

is_and() → bool

Test whether the node is the And operator.

is_or() → bool

Test whether the node is the Or operator.

is_not() → bool

Test whether the node is the Not operator.

is_implies() → bool

Test whether the node is the Implies operator.

is_iff() → bool

Test whether the node is the Iff operator.

is_exists() → bool

Test whether the node is the Exists operator.

is_always() → bool

Test whether the node is the Always constraint.

is_sometime() → bool

Test whether the node is the Sometime constraint.

is_at_most_once() → bool

Test whether the node is the At-Most-Once constraint.

is_sometime_before() → bool

Test whether the node is the Sometime-Before constraint.

is_sometime_after() → bool

Test whether the node is the Sometime-After constraint.

is_forall() → bool

Test whether the node is the Forall operator.

is_fluent_exp() → bool

Test whether the node is a Fluent Expression.

is_parameter_exp() → bool

Test whether the node is an action parameter.

is_variable_exp() → bool

Test whether the node is a Variable Expression.

is_object_exp() → bool

Test whether the node is an Object Expression.

is_timing_exp() → bool

Test whether the node is a Timing Expression.

is_plus() → bool

Test whether the node is the Plus operator.

is_minus() → bool

Test whether the node is the Minus operator.

is_times() → bool

Test whether the node is the Times operator.

is_div() → bool

Test whether the node is the Div operator.

is_equals() → bool

Test whether the node is the Equals operator.

is_le() → bool

Test whether the node is the LE operator.

is_lt() → bool

Test whether the node is the LT operator.

is_dot() → bool

Test whether the node is the DOT operator.

Equals(right)

And(*other)

Or(*other)

Not()

Xor(*other)

Implies(right)

Iff(right)