Class Union

src/main/java/wyil/lang/WyilFile.java:6163–6301

Represents a union type, which is of the form: UnionType ::= IntersectionType ('|' IntersectionType) Union types are used to compose types together. For example, the type int|null represents the type which is either an int or null . Represents t

		 * @return
		 */
		public static class Union extends AbstractType implements Type {
			public static Type create(WyilFile.Tuple<Type> types) {
				return create(types.toArray(Type.class));
			}
			/**
			 * Create a sequence of zero or more types.
			 *
			 * @param types
			 * @return
			 */
			public static Type create(Type... _types) {
				Type[] types = _types;
				for (int i = 0; i != types.length; ++i) {
					Type ith = types[i];
					if (ith instanceof Type.Union) {
						Type.Union u = (Type.Union) ith;
						Type[] nTypes = new Type[types.length + u.size() - 1];
						System.arraycopy(types, 0, nTypes, 0, i);
						System.arraycopy(u.getAll(), 0, nTypes, i, u.size());
						System.arraycopy(types, i + 1, nTypes, i + u.size(), (types.length - i - 1));
						return create(nTypes);
					} else if(ith instanceof Type.Void) {
						if(types == _types) {
							types = Arrays.copyOf(_types, _types.length);
						}
						types[i] = null;
					}
				}
				//
				types = ArrayUtils.removeAll(types, null);
				types = ArrayUtils.removeDuplicates(types);
				//
				switch (types.length) {
				case 0:
					return Type.Void;
				case 1:
					return types[0];
				default:
					return new Type.Union(types);
				}
			}

			public Union(Type... types) {
				super(TYPE_union, types);
			}

			@Override
			public boolean isWriteable() {
				for(int i=0;i!=size();++i) {
					if(!get(i).isWriteable()) {
						return false;
					}
				}
				return true;
			}

			@Override
			public boolean isReadable() {