plansys2_support_py.Parser module

Parser utilities for PlanSys2 PDDL structures.

class plansys2_support_py.Parser.Parser

Bases: object

Parser class for converting between strings and PlanSys2 PDDL structures.

This class provides utilities to parse and generate strings for PDDL elements such as parameters, nodes, and trees, following the same conventions as the C++ implementation in plansys2_pddl_parser.

static get_expr(expr: str) → Tuple[int, int]

Return expression type and start position of an expression in a string.

Parameters

exprstr: The input string.

Returns

Tuple[int, int]: Tuple of (expression_type, start_position).

static get_fun_mod(expr: str) → Tuple[int, int]

Return function modifier type and start position.

Parameters

exprstr: The input string.

Returns

Tuple[int, int]: Tuple of (modifier_type, start_position).

static get_node_type(expr: str, default_node_type: int = plansys2_msgs.msg.Node.UNKNOWN) → int

Return node type corresponding to the string input.

Parameters

exprstr: The input string.
default_node_typeint, optional: Default node type if none is found.

Returns

int: The node type.

static get_parenthesis(expr: str, start: int) → int

Find the matching closing parenthesis.

Parameters

exprstr: The expression string.
startint: Starting position of opening parenthesis.

Returns

int: Position of matching closing parenthesis.

static get_reduced_string(expr: str) → str

Remove newlines, duplicated spaces, tabs and spaces from parenthesis.

Parameters

exprstr: The expression to be reduced.

Returns

str: The reduced expression.

static get_sub_expr(expr: str) → List[str]

Extract sub-expressions from a compound expression.

Parameters

exprstr: The expression string.

Returns

List[str]: List of sub-expression strings.

static node_from_string_exists(exists: str) → plansys2_msgs.msg.Node

Create a Node from an exists expression.

Parameters

existsstr: The exists expression string.

Returns

Node: Node message with EXISTS type.

static node_from_string_function(function: str) → plansys2_msgs.msg.Node

Create a Node from a function string.

Parameters

functionstr: The function string (e.g., “(battery-level robot1)”).

Returns

Node: Node message with FUNCTION type.

static node_from_string_predicate(predicate: str) → plansys2_msgs.msg.Node

Create a Node from a predicate string.

Parameters

predicatestr: The predicate string (e.g., “(at robot1 location1)”).

Returns

Node: Node message with PREDICATE type.

static node_to_dict(node: plansys2_msgs.msg.Node) → Dict[str, Any]

Convert a plansys2_msgs.msg.Node to a dictionary.

The Node message represents elements in PDDL expression trees, including logical operators, predicates, functions, and values.

Parameters

nodeplansys2_msgs.msg.Node: The Node message to convert.

Returns

Dict[str, Any]: Dictionary representation of the Node with keys: - node_type: int - Type of node (AND, OR, NOT, PREDICATE, etc.) - node_type_name: str - Human-readable name of the node type - expression_type: int - Type of expression if applicable - expression_type_name: str - Human-readable expression type name - modifier_type: int - Type of function modifier if applicable - modifier_type_name: str - Human-readable modifier type name - node_id: int - Unique identifier for this node - children: List[int] - List of child node IDs - name: str - Node name (for predicates, functions, etc.) - parameters: List[Dict] - List of parameters (converted to dicts) - value: float - Numeric value (for NUMBER nodes) - negate: bool - Whether the node is negated

static node_to_string(node: plansys2_msgs.msg.Node) → str

Convert a Node to string representation.

Parameters

nodeNode: The Node message.

Returns

str: String representation.

static param_from_string(name: str, param_type: str = '') → plansys2_msgs.msg.Param

Create a Param from string representation.

Parameters

namestr: Parameter name.
param_typestr, optional: Parameter type.

Returns

Param: Param message.

static param_to_dict(param: plansys2_msgs.msg.Param) → Dict[str, Any]

Convert a plansys2_msgs.msg.Param to a dictionary.

Parameters

paramplansys2_msgs.msg.Param: The Param message to convert.

Returns

Dict[str, Any]: Dictionary representation of the Param with keys: - name: str - Parameter name - type: str - Parameter type - sub_types: List[str] - List of sub-types (for complex types)

static param_to_string(param: plansys2_msgs.msg.Param) → str

Convert a Param to string representation.

Parameters

paramParam: The Param message.

Returns

str: String representation.

static tree_from_string(expr: str, negate: bool = False, parent: int = plansys2_msgs.msg.Node.UNKNOWN) → plansys2_msgs.msg.Tree

Create a Tree from a string expression.

Parameters

exprstr: The expression string.
negatebool, optional: Whether to negate the expression.
parentint, optional: Parent node type for context.

Returns

Tree: Tree message.

static tree_to_dict(tree: plansys2_msgs.msg.Tree) → Dict[str, Any]

Convert a plansys2_msgs.msg.Tree to a dictionary.

The Tree message represents a PDDL construct as a tree structure composed of Node elements.

Parameters

treeplansys2_msgs.msg.Tree: The Tree message to convert.

Returns

Dict[str, Any]: Dictionary representation of the Tree with keys: - nodes: List[Dict] - List of nodes (converted to dicts)

static tree_to_string(tree: plansys2_msgs.msg.Tree, node_id: int = 0, negate: bool = False) → str

Convert a Tree to string representation.

Parameters

treeTree: The Tree message.
node_idint, optional: Starting node ID (default: 0).
negatebool, optional: Whether to negate the expression.

Returns

str: String representation.