Add utility class for easier building of toString

src/main/java/ch/njol/skript/effects/EffBan.java

@@ -18,15 +18,6 @@
  */
 package ch.njol.skript.effects;
 
-import java.net.InetSocketAddress;
-import java.util.Date;
-
-import org.bukkit.BanList;
-import org.bukkit.Bukkit;
-import org.bukkit.OfflinePlayer;
-import org.bukkit.entity.Player;
-import org.bukkit.event.Event;
-
 import ch.njol.skript.Skript;
 import ch.njol.skript.doc.Description;
 import ch.njol.skript.doc.Examples;
@@ -35,10 +26,19 @@
 import ch.njol.skript.lang.Effect;
 import ch.njol.skript.lang.Expression;
 import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.skript.lang.SyntaxStringBuilder;
 import ch.njol.skript.util.Timespan;
 import ch.njol.util.Kleenean;
+import org.bukkit.BanList;
+import org.bukkit.Bukkit;
+import org.bukkit.OfflinePlayer;
+import org.bukkit.entity.Player;
+import org.bukkit.event.Event;
 import org.jetbrains.annotations.Nullable;
 
+import java.net.InetSocketAddress;
+import java.util.Date;
+
 @Name("Ban")
 @Description({"Bans or unbans a player or an IP address.",
 	"If a reason is given, it will be shown to the player when they try to join the server while banned.",
@@ -54,7 +54,7 @@
 	"ban and kick player due to \"inappropriate language\" for 2 days"})
 @Since("1.4, 2.1.1 (ban reason), 2.5 (timespan), 2.9.0 (kick)")
 public class EffBan extends Effect {
-	
+
 	static {
 		Skript.registerEffect(EffBan.class,
 			"ban [kick:and kick] %strings/offlineplayers% [(by reason of|because [of]|on account of|due to) %-string%] [for %-timespan%]",
@@ -64,18 +64,18 @@ public class EffBan extends Effect {
 			"IP(-| )ban [kick:and kick] %players% [(by reason of|because [of]|on account of|due to) %-string%] [for %-timespan%]",
 			"(IP(-| )unban|un[-]IP[-]ban) %players%");
 	}
-	
+
 	@SuppressWarnings("null")
 	private Expression<?> players;
 	@Nullable
 	private Expression<String> reason;
 	@Nullable
 	private Expression<Timespan> expires;
-	
+
 	private boolean ban;
 	private boolean ipBan;
 	private boolean kick;
-	
+
 	@SuppressWarnings({"null", "unchecked"})
 	@Override
 	public boolean init(final Expression<?>[] exprs, final int matchedPattern, final Kleenean isDelayed, final ParseResult parseResult) {
@@ -87,7 +87,7 @@ public boolean init(final Expression<?>[] exprs, final int matchedPattern, final
 		kick = parseResult.hasTag("kick");
 		return true;
 	}
-	
+
 	@SuppressWarnings("null")
 	@Override
 	protected void execute(final Event e) {
@@ -137,15 +137,23 @@ protected void execute(final Event e) {
 			}
 		}
 	}
-	
+
 	@Override
-	public String toString(final @Nullable Event event, final boolean debug) {
-		return (ipBan ? "IP-" : "") +
-			(this.ban ? "ban " : "unban ") +
-			(kick ? "and kick " : "") +
-			this.players.toString(event, debug) +
-			(this.reason != null ? " on account of " + this.reason.toString(event, debug) : "") +
-			(expires != null ? " for " + expires.toString(event, debug) : "");
+	public String toString(@Nullable Event event, boolean debug) {
+		SyntaxStringBuilder builder = new SyntaxStringBuilder(event, debug);
+
+		if (ipBan)
+			builder.append("IP");
+		builder.append(ban ? "ban" : "unban");
+		if (kick)
+			builder.append("and kick");
+		builder.append(players);
+		if (reason != null)
+			builder.append("on account of", reason);
+		if (expires != null)
+			builder.append("for", expires);
+
+		return builder.toString();
 	}
-	
+
 }

src/main/java/ch/njol/skript/effects/EffReplace.java

@@ -31,6 +31,7 @@
 import ch.njol.skript.lang.Expression;
 import ch.njol.skript.lang.ExpressionList;
 import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.skript.lang.SyntaxStringBuilder;
 import ch.njol.util.Kleenean;
 import ch.njol.util.StringUtils;
 import org.bukkit.event.Event;
@@ -140,11 +141,16 @@ private void replace(Event event, Object[] needles, Expression<?> haystackExpr)
 
 	@Override
 	public String toString(@Nullable Event event, boolean debug) {
+		SyntaxStringBuilder builder = new SyntaxStringBuilder(event, debug);
+
+		builder.append("replace");
 		if (replaceFirst)
-			return "replace first " + needles.toString(event, debug) + " in " + haystack.toString(event, debug) + " with " + replacement.toString(event, debug)
-					+ "(case sensitive: " + caseSensitive + ")";
-		return "replace " + needles.toString(event, debug) + " in " + haystack.toString(event, debug) + " with " + replacement.toString(event, debug)
-				+ "(case sensitive: " + caseSensitive + ")";
+			builder.append("the first");
+		builder.append(needles, "in", haystack, "with", replacement);
+		if (caseSensitive)
+			builder.append("with case sensitivity");
+
+		return builder.toString();
 	}
-	
+
 }

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

@@ -0,0 +1,64 @@
+package ch.njol.skript.lang;
+
+import com.google.common.base.Preconditions;
+import org.bukkit.event.Event;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.StringJoiner;
+
+/**
+ * Utility class to build syntax strings, primarily intended for use
+ * in {@link Debuggable#toString(Event, boolean)} implementations.
+ */
+public class SyntaxStringBuilder {
+
+	private final boolean debug;
+	private final @Nullable Event event;
+	private final StringJoiner joiner = new StringJoiner(" ");
+
+	/**
+	 * Creates a new SyntaxStringBuilder.
+	 *
+	 * @param event The event to get information from. This is always null if debug == false.
+	 * @param debug If true this should print more information, if false this should print what is shown to the end user
+	 */
+	public SyntaxStringBuilder(@Nullable Event event, boolean debug) {
+		this.event = event;
+		this.debug = debug;
+	}
+
+	/**
+	 * Adds an object to the string.
+	 * @param object The object to add.
+	 */
+	public void append(Object object) {
+		Preconditions.checkNotNull(object);
+		joiner.add(object.toString());
+	}
+
+	/**
+	 * Adds a {@link Debuggable} object to the string, which is usually an expression or literal.
+	 * @param debuggable The {@link Debuggable} to add.
+	 */
+	public void append(@NotNull Debuggable debuggable) {
+		Preconditions.checkNotNull(debuggable);
+		joiner.add(debuggable.toString(event, debug));
+	}
+
+	/**
+	 * Adds multiple objects to the string.
+	 * @param objects The objects to add.
+	 */
+	public void append(@NotNull Object... objects) {
+		for (Object object : objects) {
+			append(object);
+		}
+	}
+
+	@Override
+	public String toString() {
+		return joiner.toString();
+	}
+
+}