Sather - Hello World

Hello World

class HELLO_WORLD is main is #OUT+"Hello World\n"; end; end;

A few remarks:

Class names are ALL CAPS; this is not only a convention but is enforced by the compiler.
The method called main is the entry point for execution. It may belong to any class, but if this is different from MAIN, it must be specified as a compiler option.
# is the constructor symbol, calling method create of the corresponding class; here it is used for instantiating the OUT class, which is actually stdout.
The + operator has been overloaded here to stand for stream append.
Operators such as + are syntactic sugar for conventionally named method calls: a + b stands for a.plus(b). The usual arithmetic precedence conventions are used to resolve the calling order of methods in complex formulae.
The program layout allows for pre- and post-conditions (not shown here), showing Sather's Eiffel lineage.