Allow some exceptions to be handled

src/main/java/carpet/script/exception/ThrowStatement.java

@@ -1,11 +1,68 @@
 package carpet.script.exception;
 
+import carpet.script.Context;
+import carpet.script.Expression;
+import carpet.script.Tokenizer.Token;
+import carpet.script.value.StringValue;
 import carpet.script.value.Value;
 
-public class ThrowStatement extends ExitStatement
+public class ThrowStatement extends InternalExpressionException
 {
+    public static final String UNKNOWN_ITEM        = "unknown_item";
+    public static final String UNKNOWN_BLOCK       = "unknown_block";
+    public static final String UNKNOWN_BIOME       = "unknown_biome";
+    public static final String UNKNOWN_SOUND       = "unknown_sound";
+    public static final String UNKNOWN_PARTICLE    = "unknown_particle";
+    public static final String UNKNOWN_POI_TYPE    = "unknown_poi_type";
+    public static final String UNKNOWN_DIMENSION   = "unknown_dimension";
+    public static final String UNKNOWN_STRUCTURE   = "unknown_structure";
+    public static final String UNKNOWN_CRITERION   = "unknown_criterion";
+    public static final String NBT_READ_EXCEPTION  = "nbt_read_exception";
+    public static final String JSON_READ_EXCEPTION = "json_read_exception";
+    public final Value retval;
+    /**
+     * Creates a throw exception from a value.
+     * That value will also be used as the message.<br>
+     * To use when throwing from Scarpet's {@code throw}
+     * @param value The value to pass
+     */
     public ThrowStatement(Value value)
     {
-        super(value);
+        super(value.getString());
+        retval = value;
+    }
+    
+    /**
+     * Creates a throw exception from a value, and 
+     * assigns it a specified message.<br>
+     * To use when throwing from Scarpet's {@code throw}
+     * function
+     * @param message The message to display if uncaught
+     * @param value The value to pass
+     */
+    public ThrowStatement(String message, Value value)
+    {
+        super(message);
+        retval = value;
+    }
+
+    /**
+     * Creates a throw exception.<br>
+     * Conveniently creates a value from the {@code value} String
+     * to be used easily in Java code
+     * @param message The message to display when not handled
+     * @param value A String that will be converted 
+     *              to a value to pass to {@code catch}
+     *              blocks
+     */
+    public ThrowStatement(String message, String value)
+    {
+        super(message);
+        retval = new StringValue(value);
+    }
+    
+    @Override
+    public ExpressionException promote(Context c, Expression e, Token token) {
+        return new ProcessedThrowStatement(c, e, token, getMessage(), stack, retval);
     }
 }