SimplifiedCondition

src/main/java/ch/njol/skript/conditions/CondAlphanumeric.java

@@ -42,7 +42,12 @@ public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelaye
 	public boolean check(Event e) {
 		return isNegated() ^ strings.check(e, StringUtils::isAlphanumeric);
 	}
-
+
+	@Override
+	public Condition simplify() {
+		return simplifyWith(strings);
+	}
+
 	@Override
 	public String toString(@Nullable Event e, boolean debug) {
 		return strings.toString(e, debug) + " is" + (isNegated() ? "n't" : "") + " alphanumeric";

src/main/java/ch/njol/skript/conditions/CondCompare.java

@@ -397,6 +397,11 @@ private boolean compareLists(Event event) {
 		return shouldMatch;
 	}
 
+	@Override
+	public Condition simplify() {
+		return simplifyWith(first, second, third);
+	}
+
 	@Override
 	public String toString(final @Nullable Event event, final boolean debug) {
 		String s;

src/main/java/ch/njol/skript/conditions/CondContains.java

@@ -3,29 +3,28 @@
 import ch.njol.skript.Skript;
 import ch.njol.skript.SkriptConfig;
 import ch.njol.skript.aliases.ItemType;
-import ch.njol.skript.lang.VerboseAssert;
-import ch.njol.skript.lang.util.common.AnyContains;
-import ch.njol.skript.util.LiteralUtils;
-import org.skriptlang.skript.lang.comparator.Relation;
 import ch.njol.skript.doc.Description;
 import ch.njol.skript.doc.Examples;
 import ch.njol.skript.doc.Name;
 import ch.njol.skript.doc.Since;
 import ch.njol.skript.lang.Condition;
 import ch.njol.skript.lang.Expression;
 import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.skript.lang.VerboseAssert;
 import ch.njol.skript.lang.util.SimpleExpression;
-import org.skriptlang.skript.lang.comparator.Comparators;
+import ch.njol.skript.lang.util.common.AnyContains;
+import ch.njol.skript.util.LiteralUtils;
 import ch.njol.util.Kleenean;
 import ch.njol.util.StringUtils;
 import org.bukkit.event.Event;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.ItemStack;
-import org.skriptlang.skript.lang.converter.Converters;
 import org.jetbrains.annotations.Nullable;
+import org.skriptlang.skript.lang.comparator.Comparators;
+import org.skriptlang.skript.lang.comparator.Relation;
+import org.skriptlang.skript.lang.converter.Converters;
 
 import java.util.Arrays;
-import java.util.List;
 import java.util.Objects;
 import java.util.StringJoiner;
 
@@ -183,6 +182,11 @@ public String getReceivedMessage(Event event) {
 		return joiner.toString();
 	}
 
+	@Override
+	public Condition simplify() {
+		return simplifyWith(containers, items);
+	}
+
 	@Override
 	public String toString(@Nullable Event e, boolean debug) {
 		return containers.toString(e, debug) + (isNegated() ? " doesn't contain " : " contains ") + items.toString(e, debug);

src/main/java/ch/njol/skript/conditions/CondDate.java

@@ -58,7 +58,12 @@ public boolean check(final Event e) {
 						timespan -> now - date.getTime() >= timespan.getAs(Timespan.TimePeriod.MILLISECOND)
 				), isNegated());
 	}
-
+
+	@Override
+	public Condition simplify() {
+		return simplifyWith(date, delta);
+	}
+
 	@Override
 	public String toString(final @Nullable Event e, final boolean debug) {
 		return date.toString(e, debug) + " was " + (isNegated() ? "less" : "more") + " than " + delta.toString(e, debug) + " ago";

src/main/java/ch/njol/skript/conditions/CondIsFuel.java

@@ -1,15 +1,14 @@
 package ch.njol.skript.conditions;
 
-import org.bukkit.Material;
-
 import ch.njol.skript.Skript;
 import ch.njol.skript.aliases.ItemType;
 import ch.njol.skript.conditions.base.PropertyCondition;
 import ch.njol.skript.doc.Description;
 import ch.njol.skript.doc.Examples;
 import ch.njol.skript.doc.Name;
-import ch.njol.skript.doc.RequiredPlugins;
 import ch.njol.skript.doc.Since;
+import ch.njol.skript.lang.Condition;
+import org.bukkit.Material;
 
 @Name("Is Fuel")
 @Description("Checks whether an item can be used as fuel in a furnace.")
@@ -32,7 +31,12 @@ public class CondIsFuel extends PropertyCondition<ItemType> {
 	public boolean check(ItemType item) {
 		return item.getMaterial().isFuel();
 	}
-
+
+	@Override
+	public Condition simplify() {
+		return simplifyWith(getExpr());
+	}
+
 	@Override
 	protected String getPropertyName() {
 		return "fuel";

src/main/java/ch/njol/skript/conditions/CondIsInfinite.java

@@ -5,6 +5,7 @@
 import ch.njol.skript.doc.Example;
 import ch.njol.skript.doc.Name;
 import ch.njol.skript.doc.Since;
+import ch.njol.skript.lang.Condition;
 import ch.njol.skript.util.Timespan;
 import org.bukkit.potion.PotionEffect;
 
@@ -28,6 +29,11 @@ public boolean check(Object object) {
 		return false;
 	}
 
+	@Override
+	public Condition simplify() {
+		return simplifyWith(getExpr());
+	}
+
 	@Override
 	protected String getPropertyName() {
 		return "infinite";

src/main/java/ch/njol/skript/conditions/CondIsVectorNormalized.java

@@ -5,6 +5,7 @@
 import ch.njol.skript.doc.Examples;
 import ch.njol.skript.doc.Name;
 import ch.njol.skript.doc.Since;
+import ch.njol.skript.lang.Condition;
 import org.bukkit.util.Vector;
 
 @Name("Is Normalized")
@@ -21,7 +22,12 @@ public class CondIsVectorNormalized extends PropertyCondition<Vector> {
 	public boolean check(Vector vector) {
 		return vector.isNormalized();
 	}
-
+
+	@Override
+	public Condition simplify() {
+		return simplifyWith(getExpr());
+	}
+
 	@Override
 	protected String getPropertyName() {
 		return "normalized";

src/main/java/ch/njol/skript/conditions/CondMatches.java

@@ -1,12 +1,6 @@
 
 package ch.njol.skript.conditions;
 
-import java.util.Arrays;
-import java.util.regex.Pattern;
-
-import org.bukkit.event.Event;
-import org.jetbrains.annotations.Nullable;
-
 import ch.njol.skript.Skript;
 import ch.njol.skript.doc.Description;
 import ch.njol.skript.doc.Examples;
@@ -16,6 +10,11 @@
 import ch.njol.skript.lang.Expression;
 import ch.njol.skript.lang.SkriptParser.ParseResult;
 import ch.njol.util.Kleenean;
+import org.bukkit.event.Event;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Arrays;
+import java.util.regex.Pattern;
 
 @Name("Matches")
 @Description("Checks whether the defined strings match the input regexes (Regular expressions).")
@@ -75,7 +74,12 @@ public boolean check(Event e) {
 	public boolean matches(String str, Pattern pattern) {
 		return partial ? pattern.matcher(str).find() : str.matches(pattern.pattern());
 	}
-
+
+	@Override
+	public Condition simplify() {
+		return simplifyWith(strings, regex);
+	}
+
 	@Override
 	public String toString(@Nullable Event e, boolean debug) {
 		return strings.toString(e, debug) + " " + (isNegated() ? "doesn't match" : "matches") + " " + regex.toString(e, debug);

src/main/java/ch/njol/skript/conditions/CondMinecraftVersion.java

@@ -40,7 +40,12 @@ public boolean check(Event e) {
 		String ver = version.getSingle(e);
 		return ver != null ? Skript.isRunningMinecraft(new Version(ver)) ^ isNegated() : false;
 	}
-
+
+	@Override
+	public Condition simplify() {
+		return simplifyWith(version);
+	}
+
 	@Override
 	public String toString(@Nullable Event e, boolean debug) {
 		return "is running minecraft " + version.toString(e, debug);

src/main/java/ch/njol/skript/conditions/CondPastFuture.java

@@ -78,6 +78,11 @@ public boolean check(Event event) {
 		return dates.check(event, date -> date.compareTo(new Date()) < 0, isNegated());
 	}
 
+	@Override
+	public Condition simplify() {
+		return simplifyWith(dates);
+	}
+
 	@Override
 	public String toString(@Nullable Event event, boolean debug) {
 		return dates.toString(event, debug) + (dates.isSingle() ? " is"  : " are") + " in the" + (isFuture ? " future" : " past");

src/main/java/ch/njol/skript/conditions/CondStartsEndsWith.java

@@ -80,7 +80,12 @@ public boolean check(Event e) {
 			},
 			isNegated());
 	}
-
+
+	@Override
+	public Condition simplify() {
+		return simplifyWith(strings, affix);
+	}
+
 	@Override
 	public String toString(@Nullable Event e, boolean debug) {
 		if (isNegated())

src/main/java/ch/njol/skript/lang/Condition.java

@@ -3,7 +3,9 @@
 import ch.njol.skript.Skript;
 import ch.njol.skript.conditions.base.PropertyCondition;
 import ch.njol.skript.config.Node;
+import ch.njol.skript.lang.simplification.Simplifiable;
 import ch.njol.skript.lang.util.SimpleExpression;
+import ch.njol.skript.test.runner.TestMode;
 import ch.njol.util.Kleenean;
 import org.bukkit.event.Event;
 import org.jetbrains.annotations.ApiStatus;
@@ -22,7 +24,7 @@
  *
  * @see Skript#registerCondition(Class, String...)
  */
-public abstract class Condition extends Statement implements Conditional<Event>, SyntaxRuntimeErrorProducer {
+public abstract class Condition extends Statement implements Conditional<Event>, SyntaxRuntimeErrorProducer, Simplifiable<Condition> {
 
 	public enum ConditionType {
 		/**
@@ -117,6 +119,40 @@ public Node getNode() {
 		return "condition";
 	}
 
+	@Override
+	public Condition simplify() {
+		return this;
+	}
+
+	/**
+	 * Helper method for simplifying this {@link Condition} using the {@link Expression}s it requires to be evaluated.
+	 * Providing no {@link Expression}s will result in a failed simplification process.
+	 *
+	 * @param exprs The {@link Expression}s required for evaluation.
+	 * @return {@link SimplifiedCondition} if all of {@code exprs} are {@link Literal}s, otherwise {@code this}.
+	 */
+	public Condition simplifyWith(Expression<?>... exprs) {
+		return simplifyWith(TestMode.DEV_MODE, exprs);
+	}
+
+	/**
+	 * Helper method for simplifying this {@link Condition} using the {@link Expression}s it requires to be evaluated.
+	 * Providing no {@link Expression}s will result in a failed simplification process.
+	 *
+	 * @param warn Whether a warning should be outputted if it's simplifiable.
+	 * @param exprs The {@link Expression}s required for evaluation.
+	 * @return {@link SimplifiedCondition} if all of {@code exprs} are {@link Literal}s, otherwise {@code this}.
+	 */
+	public Condition simplifyWith(boolean warn, Expression<?>... exprs) {
+		if (exprs.length == 0)
+			return this;
+		for (Expression<?> expr : exprs) {
+			if (expr != null && !(expr instanceof Literal<?>))
+				return this;
+		}
+		return SimplifiedCondition.fromCondition(this, warn);
+	}
+
 	/**
 	 * Parse a raw string input as a condition.
 	 * 

src/main/java/ch/njol/skript/lang/SimplifiedCondition.java

@@ -0,0 +1,98 @@
+package ch.njol.skript.lang;
+
+import ch.njol.skript.Skript;
+import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.skript.lang.parser.ParserInstance;
+import ch.njol.skript.lang.util.ContextlessEvent;
+import ch.njol.util.Kleenean;
+import org.bukkit.event.Event;
+import org.jetbrains.annotations.Nullable;
+import org.skriptlang.skript.lang.script.Script;
+import org.skriptlang.skript.lang.script.ScriptWarning;
+
+/**
+ * Represents a condition that can be simplified during initialization.
+ */
+public class SimplifiedCondition extends Condition {
+
+	/**
+	 * Creates a new {@link SimplifiedCondition} from a {@link Condition} by evaluating it with a {@link ContextlessEvent}.
+	 * Any expression used by {@code original} that requires specific event data cannot be safely simplified.
+	 *
+	 * @param original The original {@link Condition} to simplify.
+	 * @return A new {@link SimplifiedCondition}.
+	 */
+	public static Condition fromCondition(Condition original) {
+		return fromCondition(original, true);
+	}
+
+	/**
+	 * Creates a new {@link SimplifiedCondition} from a {@link Condition} by evaluating it with a {@link ContextlessEvent}.
+	 * Any expression used by {@code original} that requires specific event data cannot be safely simplified.
+	 *
+	 * @param original The original {@link Condition} to simplify.
+	 * @param warn Whether a warning should be outputted.
+	 * @return A new {@link SimplifiedCondition}.
+	 */
+	public static Condition fromCondition(Condition original, boolean warn) {
+		if (original instanceof SimplifiedCondition simplifiedCondition)
+			return simplifiedCondition;
+
+		Event event = ContextlessEvent.get();
+		boolean result = original.check(event);
+
+		if (warn) {
+			ParserInstance parser = ParserInstance.get();
+			Script script = parser.isActive() ? parser.getCurrentScript() : null;
+			if (script != null && !script.suppressesWarning(ScriptWarning.CONSTANT_CONDITION)) {
+				Skript.warning("The condition '" + original + "' will always be " + (result ? "true" : "false") + ".");
+			}
+		}
+
+		return new SimplifiedCondition(original, result);
+	}
+
+	private final Condition source;
+	private final boolean result;
+
+	/**
+	 * Constructs a new {@link SimplifiedCondition}.
+	 *
+	 * @param source The source {@link Condition} this was created from.
+	 * @param result The evaluated result from {@code source} via {@link Condition#check(Event)}.
+	 */
+	private SimplifiedCondition(Condition source, boolean result) {
+		this.source = source;
+		this.result = result;
+	}
+
+	/**
+	 * Returns the source {@link Condition} used to create this {@link SimplifiedCondition}.
+	 */
+	public Condition getSource() {
+		return source;
+	}
+
+	/**
+	 * Returns the result that was evaluated from {@link #source} during initialization.
+	 */
+	public boolean getResult() {
+		return result;
+	}
+
+	@Override
+	public boolean init(Expression<?>[] expressions, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	public boolean check(Event event) {
+		return result;
+	}
+
+	@Override
+	public String toString(@Nullable Event event, boolean debug) {
+		return source.toString(event, debug);
+	}
+
+}