std/lang

std/lang — exception subclass cascade.

Object and the throwable root Exception live in
runtime/lang (axle_runtime). This file carries the stdlib-level
subclass hierarchy, declared with the exception form:

exception ThingError : IOException {
path: string,
constructor(message: string, path: string) {
super(message);
self.path = path;
}
}

Subclass catch dispatch is wired: catch e : Exception matches
Exception plus every exception whose base chain reaches it, so
catching a base type catches every subclass.

Field inheritance: an exception inherits its base's fields and
prepends them to its own. So exception IOException gets message
from Exception — e.message resolves correctly in catch blocks.

C class RuntimeException

Root of the unchecked branch — a programming-error condition the
caller is not forced to declare or catch.

C class IllegalArgumentException

An argument fails the precondition of the called operation.

C class IllegalStateException

The object is in a state where the requested operation is invalid.

C class NullPointerException

A null reference was dereferenced.

C class IndexOutOfBoundsException

An index falls outside the valid range of a sequence.

C class ArithmeticException

An arithmetic fault, e.g. integer division by zero.

C class ClassCastException

A cast to an incompatible runtime type was attempted.

C class UnsupportedOperationException

The requested operation is not implemented for this type.

C class NoSuchElementException

An iteration or lookup found no element to return.

C class ConcurrentModificationException

A collection was mutated while being iterated.

C class IOException

Root of the I/O failure branch.

C class FileNotFoundException

The requested file or directory does not exist.

C class EOFException

End of stream reached before the expected data.

C class SocketException

A socket-level networking failure.

C class ConnectException

Establishing a connection to the remote endpoint failed.

C class HttpException

An HTTP request or response was rejected at the protocol level.

C class InterruptedException

A blocking wait was interrupted before it could complete.

C class TimeoutException

A bounded wait expired before the operation finished.

C class ParseException

Input could not be parsed into the requested form.

C class DefaultRankable

Minimal Rankable that keeps the default rank().

Constructors

Method detail

T trait Rankable

A type with a ranking, defaulting to the lowest rank. Implementers may
override rank(); those that omit it inherit this default.

i32

Method detail