Files
fabric-carpet/src/main/java/carpet/script/exception/Throwables.java
T

128 lines
6.1 KiB
Java

package carpet.script.exception;
import java.util.HashMap;
import java.util.Map;
import carpet.script.value.NullValue;
import carpet.script.value.StringValue;
import carpet.script.value.Value;
/**
* This class contains default Scarpet catchable exception's ids, as well as their inheritance and
* methods to check whether filters are compatible with those.
*
* Exceptions here cannot be thrown as an actual {@link Throwable}, they are just part of the metadata for
* {@link ThrowStatement} and {@link ProcessedThrowStatement}
*/
public class Throwables {
protected static final Map<Value, Exception> byValue = new HashMap<>();
public static final Exception EXCEPTION = register("exception", null);
public static final Exception VALUE_EXCEPTION = register("value_exception", EXCEPTION);
public static final Exception UNKNOWN_ITEM = register("unknown_item", VALUE_EXCEPTION);
public static final Exception UNKNOWN_BLOCK = register("unknown_block", VALUE_EXCEPTION);
public static final Exception UNKNOWN_BIOME = register("unknown_biome", VALUE_EXCEPTION);
public static final Exception UNKNOWN_SOUND = register("unknown_sound", VALUE_EXCEPTION);
public static final Exception UNKNOWN_PARTICLE = register("unknown_particle", VALUE_EXCEPTION);
public static final Exception UNKNOWN_POI_TYPE = register("unknown_poi_type", VALUE_EXCEPTION);
public static final Exception UNKNOWN_DIMENSION = register("unknown_dimension", VALUE_EXCEPTION);
public static final Exception UNKNOWN_STRUCTURE = register("unknown_structure", VALUE_EXCEPTION);
public static final Exception UNKNOWN_CRITERION = register("unknown_criterion", VALUE_EXCEPTION);
public static final Exception FILE_READ_EXCEPTION = register("file_read_exception", EXCEPTION);
public static final Exception NBT_READ = register("nbt_read_exception", FILE_READ_EXCEPTION);
public static final Exception JSON_READ = register("json_read_exception", FILE_READ_EXCEPTION);
public static final Exception USER_DEFINED = register("user_defined_exception", EXCEPTION);
protected static final Exception ERROR = register("error", null);
private Throwables() {}
/**
* Creates an exception and registers it to be used as parent for
* user defined exceptions in Scarpet's throw function.
* <p>Scarpet exceptions should, in general, have a top-level parent being {@link Throwables#EXCEPTION}
* @param value The value for the exception as a {@link String}. Will be converted into a {@link StringValue}
* @param parent The parent of the exception being created, or <code>null</code> if top-level
* @return The created exception
*/
public static Exception register(String value, Exception parent)
{
Exception exc = new Exception(value, parent);
byValue.put(exc.getValue(), exc);
return exc;
}
/**
* The data of a {@link ThrowStatement} exception. Supports creating with inheritance and
* checking whether a filter is compatible with them.
*/
public static class Exception {
private final Value value;
private final Exception parent;
private final boolean isError;
/**
* Creates a new exception, with an optional parent.
* <p>To be used in Scarpet's throw command
* <p>Parent will default to {@link Throwables#USER_DEFINED} if provided
* parentValue meets Value#isNull, else it will create a new {@link Exception},
* with its parent being {@link Throwables#USER_DEFINED}.
* @param value The {@link Value} of the exception
* @param parentValue An optional {@link Value} matching the name of a parent exception.
* <br>Accepts a {@link NullValue}, but not a {@code null}
*/
public Exception(Value value, Value parentValue)
{
if (byValue.containsKey(value))
throw new InternalExpressionException("Exception value can't be the same as existing exception. Use it as parent instead");
this.value = value;
if (!parentValue.isNull())
{
Exception possibleParent = byValue.get(parentValue);
parent = possibleParent == null ? new Exception(parentValue, Value.NULL) : possibleParent;
} else
parent = USER_DEFINED;
isError = this.parent == ERROR;
}
/**
* Creates a new exception.
* <p>Not suitable for creating exceptions that can't be caught.
* Use an {@link InternalExpressionException} for that
* @param value The exception's value as a {@link String}
* @param parent The parent exception, or <code>null</code> if no parent is available
*/
protected Exception(String value, Exception parent)
{
this.value = StringValue.of(value);
this.parent = parent;
this.isError = false;
}
/**
* Checks whether the given filter matches an instance of this exception, including checking equality
* with itself and possible parents.
* @param filter The {@link Value} to check against
* @return Whether or not the given value matches this exception's hierarchy
*/
public boolean isInstance(Value filter) {
return getValue().equals(filter) || (parent != null && parent.isInstance(filter));
}
/**
* Returns the {@link Value} provided when creating this exception
* @return The {@link Value} of this exception
*/
public Value getValue() {
return value;
}
/**
* Returns whether this exception has been defined as an error.
* <p> Error exceptions cannot be caught in Scarpet
* @return Whether this exception has been defined as an error
*/
public boolean isError() {
return isError;
}
}
}