Package jason.stdlib

Class prefix

java.lang.Object

jason.asSemantics.DefaultInternalAction

jason.stdlib.prefix

All Implemented Interfaces:

InternalAction, Serializable

@Manual(literal=".prefix(prefix,list)",
        hint="checks if some list is a prefix of other list, backtracking all free variables",
        argsHint={"the prefix to be checked","the list where the prefix is from"},
        argsType={"list","list"},
        examples={".prefix([a],[a,b,c]): true",".prefix([a,b],[a,b,c]): true",".prefix([b,c],[a,b,c]): false",".prefix(X,[a,b,c]): unifies X with any prefix of the list, i.e., [a,b,c], [a,b], [a], and [] in this order"},
        seeAlso={"jason.stdlib.concat","jason.stdlib.length","jason.stdlib.sublist","jason.stdlib.sort","jason.stdlib.shuffle","jason.stdlib.suffix","jason.stdlib.nth","jason.stdlib.max","jason.stdlib.min","jason.stdlib.reverse","jason.stdlib.difference","jason.stdlib.intersection","jason.stdlib.union"})
public class prefix
extends DefaultInternalAction

Internal action: .prefix(P,L).

Description: checks if some list/string P is a prefix of list/stringL. If P has free variables, this internal action backtracks all possible values for P.

Parameters:

• +/- prefix (list or string): the prefix to be checked.
• + list (list or string): the list where the prefix is from.

Examples:

• .prefix([a],[a,b,c]): true.
• .prefix([a,b],[a,b,c]): true.
• .prefix([b,c],[a,b,c]): false.
• .prefix(X,[a,b,c]): unifies X with any prefix of the list, i.e., [a,b,c], [a,b], [a], and [] in this order; note that this is different from what its usual implementation in logic programming would result, where the various prefixes are returned in increasing lengths instead.
• .prefix("a","abc"): true.
• .prefix("bc","abc"): false.
• .prefix(X,"abc"): unifies X with any prefix of the string, i.e., "abc", "ab", "a", and "" in this order.

See Also:

• concat
• length
• sort
• nth
• max
• min
• reverse
• suffix
• sublist
• difference
• intersection
• union
• Serialized Form

Constructor Summary

Constructors

Constructor	Description
prefix()

Method Summary

Modifier and Type	Method	Description
protected void	checkArguments(Term[] args)
static InternalAction	create()
Object	execute(TransitionSystem ts, Unifier un, Term[] args)	Executes the internal action.
int	getMaxArgs()
int	getMinArgs()

Methods inherited from class jason.asSemantics.DefaultInternalAction

canBeUsedInContext, destroy, prepareArguments, suspendIntention

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

prefix

public prefix()

Method Details

create

public static InternalAction create()

getMinArgs

public int getMinArgs()

Overrides:

getMinArgs in class DefaultInternalAction

getMaxArgs

public int getMaxArgs()

Overrides:

getMaxArgs in class DefaultInternalAction

checkArguments

protected void checkArguments(Term[] args)
                       throws JasonException

Overrides:

checkArguments in class DefaultInternalAction

Throws:

JasonException

execute

public Object execute(TransitionSystem ts,
 Unifier un,
 Term[] args)
               throws Exception

Description copied from interface: InternalAction

Executes the internal action. It should return a Boolean or an Iterator. A true boolean return means that the IA was successfully executed. An Iterator result means that there is more than one answer for this IA (e.g. see member internal action).

Specified by:

execute in interface InternalAction

Overrides:

execute in class DefaultInternalAction

Throws:

Exception