Package ch.njol.skript.lang

Class Variable<T>

java.lang.Object
ch.njol.skript.lang.Variable<T>
All Implemented Interfaces:
Debuggable, Expression<T>, KeyProviderExpression<T>, KeyReceiverExpression<T>, Loopable<T>, Simplifiable<Expression<? extends T>>, SyntaxElement
public class Variable<T> extends Object implements Expression<T>, KeyReceiverExpression<T>, KeyProviderExpression<T>

  • Field Details

  • Method Details

    • isValidVariableName

      public static boolean isValidVariableName(String name, boolean allowListVariable, boolean printErrors)
      Checks whether a string is a valid variable name. This is used to verify variable names as well as command and function arguments.
      Parameters:
      name - The name to test
      allowListVariable - Whether to allow a list variable
      printErrors - Whether to print errors when they are encountered
      Returns:
      true if the name is valid, false otherwise.

    • newInstance

      @Nullable public static <T> @Nullable Variable<T> newInstance(String name, Class<? extends T>[] types)
      Creates a new variable instance with the given name and types. Prints errors.
      Type Parameters:
      T - The supertype the variable is expected to be.
      Parameters:
      name - The raw name of the variable.
      types - The types this variable is expected to be.
      Returns:
      A new variable instance, or null if the name is invalid or the variable could not be created.

    • init

      public boolean init(Expression<?>[] expressions, int matchedPattern, Kleenean isDelayed, SkriptParser.ParseResult parseResult)
      Description copied from interface: SyntaxElement
      Called just after the constructor and SyntaxElement.preInit().
      Specified by:
      init in interface SyntaxElement
      Parameters:
      expressions - all %expr%s included in the matching pattern in the order they appear in the pattern. If an optional value was left out, it will still be included in this list holding the default value of the desired type, which usually depends on the event.
      matchedPattern - The index of the pattern which matched
      isDelayed - Whether this expression is used after a delay or not (i.e. if the event has already passed when this expression will be called)
      parseResult - Additional information about the match.
      Returns:
      Whether this expression was initialised successfully. An error should be printed prior to returning false to specify the cause.
      See Also:

    • isLocal

      public boolean isLocal()
      Returns:
      Whether this variable is a local variable, i.e. starts with LOCAL_VARIABLE_TOKEN.

    • isEphemeral

      public boolean isEphemeral()
      Returns:
      Whether this variable is an ephemeral variable, i.e. starts with EPHEMERAL_VARIABLE_TOKEN.

    • isList

      public boolean isList()
      Returns:
      Whether this variable is a list variable, i.e. ends with + "*".

    • isSingle

      public boolean isSingle()
      Description copied from interface: KeyProviderExpression
      Keyed expressions should never be single.
      Specified by:
      isSingle in interface Expression<T>
      Specified by:
      isSingle in interface KeyProviderExpression<T>
      Returns:
      true if this expression will ever only return one value at most, false if it can return multiple values.

    • getReturnType

      public Class<? extends T> getReturnType()
      Description copied from interface: Expression
      Gets the return type of this expression.
      Specified by:
      getReturnType in interface Expression<T>
      Returns:
      A supertype of any objects returned by Expression.getSingle(Event) and the component type of any arrays returned by Expression.getArray(Event)

    • possibleReturnTypes

      public Class<? extends T>[] possibleReturnTypes()
      Description copied from interface: Expression
      For expressions that might return multiple (incalculable at parse time) types, this provides a list of all possible types. Use cases include: expressions that depend on the return type of their input.
      Specified by:
      possibleReturnTypes in interface Expression<T>
      Returns:
      A list of all possible types this might return

    • toString

      public String toString(@Nullable @Nullable org.bukkit.event.Event event, boolean debug)
      Specified by:
      toString in interface Debuggable
      Parameters:
      event - The event to get information from. This is always null if debug == false.
      debug - If true this should print more information, if false this should print what is shown to the end user
      Returns:
      String representation of this object

    • toString

      public String toString()
      Description copied from interface: Debuggable
      Should return toString(null, false)
      Specified by:
      toString in interface Debuggable
      Overrides:
      toString in class Object

    • getConvertedExpression

      public <R> Variable<R> getConvertedExpression(Class<R>... to)
      Description copied from interface: Expression
      Tries to convert this expression to the given type. This method can print an error prior to returning null to specify the cause.

      Please note that expressions whose returnType is not Object will not be parsed at all for a certain class if there's no converter from the expression's returnType to the desired class. Thus this method should only be overridden if this expression's returnType is Object.

      The returned expression should delegate this method to the original expression's method to prevent excessive converted expression chains (see also ConvertedExpression).

      Specified by:
      getConvertedExpression in interface Expression<T>
      Parameters:
      to - The desired return type of the returned expression
      Returns:
      Expression with the desired return type or null if the expression can't be converted to the given type. Returns the expression itself if it already returns the desired type.
      See Also:

    • getRaw

      @Nullable public @Nullable Object getRaw(org.bukkit.event.Event event)
      Gets the value of this variable as stored in the variables map. This method also checks against default variables.

    • convertIfOldPlayer

      @Nullable public static <T> T convertIfOldPlayer(String key, boolean local, org.bukkit.event.Event event, @Nullable T object)

    • keyedIterator

      public Iterator<KeyedValue<T>> keyedIterator(org.bukkit.event.Event event)
      Description copied from interface: KeyProviderExpression
      Returns an iterator over the keyed values of this expression.
      This should only be called iff KeyProviderExpression.canReturnKeys() returns true.
      Specified by:
      keyedIterator in interface KeyProviderExpression<T>
      Parameters:
      event - The event context
      Returns:
      An iterator over the key-value pairs of this expression

    • variablesIterator

      public Iterator<Pair<String,Object>> variablesIterator(org.bukkit.event.Event event)

    • iterator

      @Nullable public @Nullable Iterator<T> iterator(org.bukkit.event.Event event)
      Description copied from interface: Loopable
      Returns the same as Expression.getArray(Event) but as an iterator. This method should be overridden by expressions intended to be looped to increase performance.
      Specified by:
      iterator in interface Loopable<T>
      Parameters:
      event - The event to be used for evaluation
      Returns:
      An iterator to iterate over all values of this expression which may be empty and/or null, but must not return null elements.
      See Also:

    • acceptChange

      public Class<?> @Nullable [] acceptChange(Changer.ChangeMode mode)
      Description copied from interface: Expression
      Tests whether this expression supports the given mode, and if yes what type it expects the delta to be.

      Use Changer.ChangerUtils.acceptsChange(Expression, ChangeMode, Class...) to test whether an expression supports changing, don't directly use this method!

      Please note that if a changer is registered for this expression's returnType this method does not have to be overridden. If you override it though make sure to return super.acceptChange(mode), and to handle the appropriate ChangeMode(s) in Expression.change(Event, Object[], ChangeMode) with super.change(...).

      Unlike Changer.acceptChange(ChangeMode) this method may print errors.

      Specified by:
      acceptChange in interface Expression<T>
      Parameters:
      mode - The mode to check
      Returns:
      An array of types that Expression.change(Event, Object[], ChangeMode) accepts as its delta parameter (which can be arrays to denote that multiple of that type are accepted), or null if the given mode is not supported. For Changer.ChangeMode.DELETE and Changer.ChangeMode.RESET this can return any non-null array to mark them as supported.

    • change

      public void change(org.bukkit.event.Event event, Object @NotNull [] delta, Changer.ChangeMode mode, @NotNull @NotNull String @NotNull [] keys)
      Description copied from interface: KeyReceiverExpression
      An alternative changer method that provides a set of keys as well as a set of values. This is only ever called for Changer.ChangeMode.supportsKeyedChange() safe change modes, where a set of values is provided. (This will never be called for valueless Changer.ChangeMode.DELETE or Changer.ChangeMode.RESET changers, for example.)
      Specified by:
      change in interface KeyReceiverExpression<T>
      Parameters:
      event - The current event context
      delta - The change values
      mode - The key-safe change mode Changer.ChangeMode.SET
      keys - The keys, matching the length and order of the values array

    • change

      public void change(org.bukkit.event.Event event, Object @Nullable [] delta, Changer.ChangeMode mode) throws UnsupportedOperationException
      Description copied from interface: Expression
      Changes the expression's value by the given amount. This will only be called on supported modes and with the desired delta type as returned by Expression.acceptChange(ChangeMode)
      Specified by:
      change in interface Expression<T>
      Parameters:
      event - The event
      delta - An array with one or more instances of one or more of the classes returned by Expression.acceptChange(ChangeMode) for the given change mode (null for Changer.ChangeMode.DELETE and Changer.ChangeMode.RESET). This can be a Object[], thus casting is not allowed.
      mode - The Changer.ChangeMode of the attempted change
      Throws:
      UnsupportedOperationException - (optional) - If this method was called on an unsupported ChangeMode.

    • changeInPlace

      public <R> void changeInPlace(org.bukkit.event.Event event, Function<T,R> changeFunction, boolean getAll)
      Changes the contents of an expression using the given Function. Intended for changes that change properties of the values of the expression, rather than completely changing the expression. For example, set vector length of {_v} to 1, rather than set {_v} to vector(0,1,0).
      This is a 1 to 1 transformation and should not add elements. Returning null will remove the element. Returning a type not accepted by Expression.acceptChange(ChangeMode) for Changer.ChangeMode.SET will depend on the implementer. The default implementation will remove the element.
      This expression must support Changer.ChangeMode.SET for this method to work.
      Specified by:
      changeInPlace in interface Expression<T>
      Type Parameters:
      R - The output type of the change function. Must be a type returned by {Expression.acceptChange(ChangeMode)} for Changer.ChangeMode.SET.
      Parameters:
      event - The event to use for local variables and evaluation
      changeFunction - A 1-to-1 function that transforms a single input to a single output. Returning null will remove the element. Returning a type not accepted by Expression.acceptChange(ChangeMode) for Changer.ChangeMode.SET will depend on the implementer. The default implementation will remove the element.
      getAll - This has no effect for a Variable, as getArray(Event) is the same as getAll(Event).

    • changeInPlace

      public <R> void changeInPlace(org.bukkit.event.Event event, Function<T,R> changeFunction)
      Description copied from interface: Expression
      Changes the contents of an expression using the given Function. Intended for changes that change properties of the values of the expression, rather than completely changing the expression. For example, set vector length of {_v} to 1, rather than set {_v} to vector(0,1,0).
      This is a 1 to 1 transformation and should not add elements. Returning null will remove the element. Returning a type not accepted by Expression.acceptChange(ChangeMode) for Changer.ChangeMode.SET will depend on the implementer. The default implementation will remove the element.
      This expression must support Changer.ChangeMode.SET for this method to work.
      Specified by:
      changeInPlace in interface Expression<T>
      Type Parameters:
      R - The output type of the change function. Must be a type returned by {Expression.acceptChange(ChangeMode)} for Changer.ChangeMode.SET.
      Parameters:
      event - The event to use for local variables and evaluation
      changeFunction - A 1-to-1 function that transforms a single input to a single output. Returning null will remove the element. Returning a type not accepted by Expression.acceptChange(ChangeMode) for Changer.ChangeMode.SET will depend on the implementer. The default implementation will remove the element.

    • getSingle

      @Nullable public T getSingle(org.bukkit.event.Event event)
      Description copied from interface: Expression
      Get the single value of this expression.

      This method may only return null if it always returns null for the given event, i.e. it is equivalent to getting a random element out of Expression.getAll(Event) or null iff that array is empty.

      Do not use this in conditions, use Expression.check(Event, Predicate, boolean) instead.

      Specified by:
      getSingle in interface Expression<T>
      Parameters:
      event - The event
      Returns:
      The value or null if this expression doesn't have any value for the event

    • getArrayKeys

      @NotNull public @NotNull String @NotNull [] getArrayKeys(org.bukkit.event.Event event) throws SkriptAPIException
      Description copied from interface: KeyProviderExpression
      A set of keys, matching the length and order of the immediately-previous Expression.getArray(Event) values array.
      This should only be called immediately after a Expression.getArray(Event) invocation, and iff KeyProviderExpression.canReturnKeys() returns true. If it is called without a matching values request (or after a delay) then the behaviour is undefined, in which case:
      • the method may throw an error,
      • the method may return keys not matching any previous values,
      • or the method may return nothing at all.
      Specified by:
      getArrayKeys in interface KeyProviderExpression<T>
      Parameters:
      event - The event context
      Returns:
      A set of keys, of the same length as Expression.getArray(Event)
      Throws:
      SkriptAPIException

    • getAllKeys

      @NotNull public @NotNull String @NotNull [] getAllKeys(org.bukkit.event.Event event)
      Description copied from interface: KeyProviderExpression
      A set of keys, matching the length and order of the immediately-previous Expression.getAll(Event) values array.
      This should only be called immediately after a Expression.getAll(Event) invocation, and iff KeyProviderExpression.canReturnKeys() returns true. If it is called without a matching values request (or after a delay) then the behaviour is undefined, in which case:
      • the method may throw an error,
      • the method may return keys not matching any previous values,
      • or the method may return nothing at all.
      Specified by:
      getAllKeys in interface KeyProviderExpression<T>
      Parameters:
      event - The event context
      Returns:
      A set of keys, of the same length as Expression.getAll(Event)

    • canReturnKeys

      public boolean canReturnKeys()
      Description copied from interface: KeyProviderExpression
      Returns whether this expression can return keys.
      If this returns false, then KeyProviderExpression.getArrayKeys(Event) and KeyProviderExpression.getAllKeys(Event) should never be called.
      Specified by:
      canReturnKeys in interface KeyProviderExpression<T>
      Returns:
      Whether this expression can return keys

    • areKeysRecommended

      public boolean areKeysRecommended()
      Description copied from interface: KeyProviderExpression
      While all keyed expressions may offer their keys, some may prefer that they are not used unless strictly required (e.g. variables).
      Specified by:
      areKeysRecommended in interface KeyProviderExpression<T>
      Returns:
      Whether the caller is recommended to ask for keys after asking for values

    • getArray

      public T[] getArray(org.bukkit.event.Event event)
      Description copied from interface: Expression
      Get all the values of this expression. The returned array is empty if this expression doesn't have any values for the given event.

      The returned array must not contain any null values.

      Do not use this in conditions, use Expression.check(Event, Predicate, boolean) instead.

      Specified by:
      getArray in interface Expression<T>
      Parameters:
      event - The event
      Returns:
      An array of values of this expression which must neither be null nor contain nulls, and which must not be an internal array.

    • getAll

      public T[] getAll(org.bukkit.event.Event event)
      Description copied from interface: Expression
      Gets all possible return values of this expression, i.e. it returns the same as Expression.getArray(Event) if Expression.getAnd() is true, otherwise all possible values for Expression.getSingle(Event).
      Specified by:
      getAll in interface Expression<T>
      Parameters:
      event - The event
      Returns:
      An array of all possible values of this expression for the given event which must neither be null nor contain nulls, and which must not be an internal array.

    • isLoopOf

      public boolean isLoopOf(String input)
      Description copied from interface: Loopable
      Checks whether the given 'loop-...' expression should match this loop, e.g. loop-block matches any loops that loop through blocks and loop-argument matches an argument loop.

      You should usually just return false as e.g. loop-block will automatically match the expression if its returnType is Block or a subtype of it.

      Specified by:
      isLoopOf in interface KeyProviderExpression<T>
      Specified by:
      isLoopOf in interface Loopable<T>
      Parameters:
      input - The entered input string (the blank in loop-___)
      Returns:
      Whether this loop matches the given string

    • check

      public boolean check(org.bukkit.event.Event event, Predicate<? super T> checker, boolean negated)
      Description copied from interface: Expression
      Checks this expression against the given checker. This is the normal version of this method and the one which must be used for simple checks, or as the innermost check of nested checks.

      Usual implementation (may differ, e.g. may return false for nonexistent values independent of negated): 

       return negated ^ Expression.check(Event, Predicate);
      Specified by:
      check in interface Expression<T>
      Parameters:
      event - The event to be used for evaluation
      checker - The checker that determines whether this expression matches
      negated - The checking condition's negated state. This is used to invert the output of the checker if set to true (i.e. negated ^ checker.check(...))
      Returns:
      Whether this expression matches or doesn't match the given checker depending on the condition's negated state.
      See Also:

    • check

      public boolean check(org.bukkit.event.Event event, Predicate<? super T> checker)
      Description copied from interface: Expression
      Checks this expression against the given checker. This method must only be used around other checks, use Expression.check(Event, Predicate, boolean) for a simple check or the innermost check of a nested check.
      Specified by:
      check in interface Expression<T>
      Parameters:
      event - The event to be used for evaluation
      checker - A checker that determines whether this expression matches
      Returns:
      Whether this expression matches the given checker
      See Also:

    • getName

      public VariableString getName()

    • getAnd

      public boolean getAnd()
      Description copied from interface: Expression
      Returns true if this expression returns all possible values, false if it only returns some of them.

      This method significantly influences Expression.check(Event, Predicate), Expression.check(Event, Predicate, boolean) and CondIsSet and thus breaks conditions that use this expression if it returns a wrong value.

      This method must return true if this is a single expression. // TODO make this method irrelevant for single expressions

      Specified by:
      getAnd in interface Expression<T>
      Returns:
      Whether this expression returns all values at once or only part of them.

    • setTime

      public boolean setTime(int time)
      Description copied from interface: Expression
      Sets the time of this expression, i.e. whether the returned value represents this expression before or after the event.

      This method will not be called if this expression is guaranteed to be used after a delay (an error will be printed immediately), but will be called if it only can be after a delay (e.g. if the preceding delay is in an if or a loop) as well as if there's no delay involved.

      If this method returns false the expression will be discarded and an error message is printed. Custom error messages must be of ErrorQuality.SEMANTIC_ERROR to be printed (NB: Skript.error(String) always creates semantic errors).

      Specified by:
      setTime in interface Expression<T>
      Parameters:
      time - -1 for past or 1 for future. 0 is never passed to this method as it represents the default state.
      Returns:
      Whether this expression has distinct time states, e.g. a player never changes but a block can. This should be sensitive for the event (using ParserInstance.isCurrentEvent(Class)).
      See Also:

    • getTime

      public int getTime()
      Specified by:
      getTime in interface Expression<T>
      Returns:
      The value passed to Expression.setTime(int) or 0 if it was never changed.
      See Also:

    • isDefault

      public boolean isDefault()
      Description copied from interface: Expression
      Returns whether this value represents the default value of its type for the event, i.e. it can be replaced with a call to event.getXyz() if one knows the event invalid input: '&' value type.

      This method might be removed in the future as it's better to check whether value == event.getXyz() for every value an expression returns.

      Specified by:
      isDefault in interface Expression<T>
      Returns:
      Whether this is the return types' default expression

    • getSource

      public Expression<?> getSource()
      Description copied from interface: Expression
      Returns the original expression that was parsed, i.e. without any conversions done.
      Specified by:
      getSource in interface Expression<T>
      Returns:
      The unconverted source expression of this expression or this expression itself if it was never converted.

    • simplify

      public Expression<? extends T> simplify()
      Description copied from interface: Simplifiable
      Simplifies this object. This should be called immediately after init() returns true. If simplification is not possible, the object is returned as is.
      References to the original object should be replaced with the simplified object.
      Any returned object should attempt to maintain the original value of Debuggable.toString(Event, boolean). An addition indicating that the value was simplified can be added in the debug string. See SimplifiedLiteral for an example.
      Simplification should never invalidate contracts. For example, any simplified expression should take care to return the same or a more specific type than the original expression, never a more generic type. Likewise, be sure to maintain the behavior of change() and acceptsChange(). Failure to do so can result in unexpected behavior and tricky bugs.
      Finally, simplified results should update Expression.getSource() to point to the expression prior to simplification. This makes maintaining the above contracts easier.
      Specified by:
      simplify in interface Expression<T>
      Specified by:
      simplify in interface Simplifiable<T>
      Returns:
      the simplified object.
      See Also:

    • supportsLoopPeeking

      public boolean supportsLoopPeeking()
      Description copied from interface: Loopable
      Checks whether the expression allows using 'next loop-value' when provided as the iterator for a SecLoop.
      Specified by:
      supportsLoopPeeking in interface Loopable<T>
      Returns: