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.