Safety mechanisms by default

A lot of mechanisms prevent common errors in Cyan:

• there cannot be any return statements inside anonymous functions
• exception handling is made using anonymous functions and, therefore, there cannot be return statements inside either try blocks or catch clauses
• there should be a space before and after = and the relational operators <, <=, >, >=, ==, and !=
• no parentheses are necessary for the if and while expressions but the brackets are required
• if statements may be nested but they should be correctly indented
• no automatic conversion between basic types, 'var Int n = 1.0'  is illegal. This prevents a lot of errors caused by the combination of overloaded methods with automatic conversion
• overloaded methods are clearly marked with keyword overload. A method overridden in a subprototype cannot be overloaded unless the superprototype method is marked with overload
• constructors init and init: can only use a limited form of overloading that makes errors associated with overloading impossible
• there are severe restrictions on the initialization of prototype fields making it very difficult to use a field before it is initialized. But in these rare cases, there will be a runtime error