Package ch.njol.skript.lang.util

Class SimpleExpression<T>

java.lang.Object
ch.njol.skript.lang.util.SimpleExpression<T>
All Implemented Interfaces:
Debuggable, Expression<T>, SyntaxElement
Direct Known Subclasses:
ContainerExpression
public abstract class SimpleExpression<T> extends Object implements Expression<T>
An implementation of the Expression interface. You should usually extend this class to make a new expression.
See Also:

  • Constructor Details

    • SimpleExpression

      protected SimpleExpression()

  • Method Details

    • getSingle

      @Nullable public final 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, Checker, 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

    • 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.

    • getArray

      public final 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, Checker, 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.

    • get

      @Nullable protected abstract T[] get(org.bukkit.event.Event event)
      This is the internal method to get an expression's values.
      To get the expression's value from the outside use getSingle(Event) or getArray(Event).
      Parameters:
      event - The event with which this expression is evaluated.
      Returns:
      An array of values for this event. May not contain nulls.

    • check

      public final boolean check(org.bukkit.event.Event event, Checker<? 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, Checker, 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:

    • check

      public final boolean check(org.bukkit.event.Event event, Checker<? 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, Checker);
      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 static <T> boolean check(@Nullable T[] values, Checker<? super T> checker, boolean invert, boolean and)

    • getConvertedExpr

      @Nullable protected <R> @Nullable ConvertedExpression<T,? extends R> getConvertedExpr(Class<R>... to)
      Converts this expression to another type. Unless the expression is special, the default implementation is sufficient.

      This method is never called with a supertype of the return type of this expression, or the return type itself.

      Parameters:
      to - The desired return type of the returned expression
      Returns:
      Expression with the desired return type or null if it can't be converted to the given type
      See Also:

    • getConvertedExpression

      @Nullable public <R> @Nullable Expression<? extends R> getConvertedExpression(Class<R>... to)
      Usually, you want to override getConvertedExpr(Class[]). However, it may be useful to override this method if you have an expression with a return type that is unknown until runtime (like variables). Usually, you'll be fine with just the default implementation. This method is final on versions below 2.2-dev36.
      Specified by:
      getConvertedExpression in interface Expression<T>
      Parameters:
      to - The desired return type of the returned expression
      Returns:
      The converted expression
      See Also:

    • acceptChange

      @Nullable public @Nullable Class<?>[] 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, @Nullable @Nullable Object[] delta, Changer.ChangeMode mode)
      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

    • setTime

      public boolean setTime(int time)
      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).

      This implementation sets the time but returns false.

      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:

    • setTime

      protected final boolean setTime(int time, Class<? extends org.bukkit.event.Event> applicableEvent)

    • setTime

      @SafeVarargs protected final boolean setTime(int time, Class<? extends org.bukkit.event.Event>... applicableEvents)

    • setTime

      protected final boolean setTime(int time, Class<? extends org.bukkit.event.Event> applicableEvent, @NotNull @NotNull Expression<?>... mustbeDefaultVars)

    • setTime

      @SafeVarargs protected final boolean setTime(int time, Expression<?> mustbeDefaultVar, Class<? extends org.bukkit.event.Event>... applicableEvents)

    • 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

    • isLoopOf

      public boolean isLoopOf(String input)
      Description copied from interface: Expression
      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 Expression<T>
      Parameters:
      input - The entered input string (the blank in loop-___)
      Returns:
      Whether this loop matches the given string

    • iterator

      @Nullable public @Nullable Iterator<? extends T> iterator(org.bukkit.event.Event event)
      Description copied from interface: Expression
      Returns the same as Expression.getArray(Event) but as an iterator. This method should be overriden by expressions intended to be looped to increase performance.
      Specified by:
      iterator in interface Expression<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.

    • 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

    • getSource

      public Expression<?> getSource()
      Description copied from interface: Expression
      Returns the original expression that was parsed, i.e. without any conversions done.

      This method is undefined for simplified expressions.

      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: Expression
      Simplifies the expression, e.g. if it only contains literals the expression may be simplified to a literal, and wrapped expressions are unwrapped.

      After this method was used the toString methods are likely not useful anymore.

      This method is not yet used but will be used to improve efficiency in the future.

      Specified by:
      simplify in interface Expression<T>
      Returns:
      A reference to a simpler version of this expression. Can change this expression directly and return itself if applicable, i.e. no references to the expression before this method call should be kept!

    • 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, Checker), Expression.check(Event, Checker, 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.