Class extended_pred_symbol

Defined in File Analyser.h

Inheritance Relationships

Base Types

public VAL::pred_symbol (Class pred_symbol)
public VAL::pred_symbol (Class pred_symbol)

Derived Type

public TIM::TIMpredSymbol (Class TIMpredSymbol)

Class Documentation

class extended_pred_symbol : public VAL::pred_symbol, public VAL::pred_symbol 

A class representing a predicate symbol, with a given combination of typed parameters. TIM creates a extended_pred_symbol for each combination of types and sub-types that can be passed to a given predicate. For instance, if we have the PDDL type structure (tea toast - item), and a predicate (cooked ?i - item), then three extended_pred_symbols are created for the cooked predicate:

one where the type of the item was typed in the problem definition as tea
one where the type of the item was typed in the problem definition as toast
one where the type of the item was typed in the problem definition as item

Each of these three has a common parent, a holding_pred_symbol, which can be obtained by using the getParent function.

Because multiple extended_pred_symbols are created for each PDDL predicate, care must be taken when interpreting the results of methods such as appearsStatic() - this will, for instance, report whether a given typed variant of the predicate is static, not necessarily whether the base PDDL predicate is static. To ascertain properties of the base predicate as a whole, use getParent() then with this iterate through all the derived extended_pred_symbols.