There are a couple of common pitfalls when a Java developer starts using Xtend.
| Java | Xtend | Description |
|---|---|---|
| String.class | typeof(String) | Get the class instance of a type |
| Long.MAX_VALUE | Long::MAX_VALUE | Accessing static fields |
| Foo.Bar | Foo$Bar | Accessing inner classes |
Example: org.slf4j logging
private Logger log = LoggerFactory.getLogger(Foo.class) // Java
Logger log = LoggerFactory::getLogger(typeof(Foo)) // Xtend
Also, the .. or upTo operator has a severe bug. The code for i: 0..list.size won’t work as expected. First of all, it will iterate once too many.
The obvious fix for i: 0..(list.size-1) doesn’t work when the list is empty because it will iterate twice (0, -1) and it won’t iterate at all if the list has a single element.
Use .. only with constant operands (i.e. 1..5 is OK, list.size..0 isn’t). If you need to iterate over a range [start … end), use this gist instead.
Tagged: Java, Xtend
