feat: add ord builtin function

Attempt to add `ord` builtin function.

src/net/sourceforge/plantuml/tim/TContext.java

@@ -121,6 +121,7 @@ import net.sourceforge.plantuml.tim.stdlib.LogicalXor;
 import net.sourceforge.plantuml.tim.stdlib.Lower;
 import net.sourceforge.plantuml.tim.stdlib.Newline;
 import net.sourceforge.plantuml.tim.stdlib.Now;
+import net.sourceforge.plantuml.tim.stdlib.Ord;
 import net.sourceforge.plantuml.tim.stdlib.RetrieveProcedure;
 import net.sourceforge.plantuml.tim.stdlib.ReverseColor;
 import net.sourceforge.plantuml.tim.stdlib.ReverseHsluvColor;
@@ -206,6 +207,7 @@ public class TContext {
 		functionsSet.addFunction(new LogicalNand());
 		functionsSet.addFunction(new LogicalNor());
 		functionsSet.addFunction(new LogicalNxor());
+		functionsSet.addFunction(new Ord());
 		// %standard_exists_function
 		// %str_replace
 		// !exit

src/net/sourceforge/plantuml/tim/stdlib/Ord.java

@@ -0,0 +1,68 @@
+/* ========================================================================
+ * PlantUML : a free UML diagram generator
+ * ========================================================================
+ *
+ * (C) Copyright 2009-2024, Arnaud Roques
+ *
+ * Project Info:  https://plantuml.com
+ *
+ * If you like this project or if you find it useful, you can support us at:
+ *
+ * https://plantuml.com/patreon (only 1$ per month!)
+ * https://plantuml.com/paypal
+ *
+ * This file is part of PlantUML.
+ *
+ * PlantUML is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * PlantUML distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
+ * USA.
+ *
+ *
+ * Original Author:  Arnaud Roques
+ *
+ */
+package net.sourceforge.plantuml.tim.stdlib;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import net.sourceforge.plantuml.tim.EaterException;
+import net.sourceforge.plantuml.tim.EaterExceptionLocated;
+import net.sourceforge.plantuml.tim.TContext;
+import net.sourceforge.plantuml.tim.TFunctionSignature;
+import net.sourceforge.plantuml.tim.TMemory;
+import net.sourceforge.plantuml.tim.expression.TValue;
+import net.sourceforge.plantuml.utils.LineLocation;
+
+public class Ord extends SimpleReturnFunction {
+
+	public TFunctionSignature getSignature() {
+		return new TFunctionSignature("%ord", 1);
+	}
+
+	public boolean canCover(int nbArg, Set<String> namedArgument) {
+		return nbArg == 1;
+	}
+
+	public TValue executeReturnFunction(TContext context, TMemory memory, LineLocation location, List<TValue> values,
+			Map<String, TValue> named) throws EaterException, EaterExceptionLocated {
+		try {
+			final int value = (int) values.get(0).toString();
+			return TValue.fromInt(value);
+		} catch (Throwable t) {
+			return TValue.fromInt(0);
+		}
+	}
+}