Functions in DART LangSpec 0.07

And here is this Functions  part for me to analyze.  Easy to read in Mobile phone.

Functions

Functions abstract over executable actions.
functionSignature:
   returnType? identifier formalParameterList
   ;
returnType:
     void
   | type
    ;


functionBody:
     '=>' expression ';'
   | block
   ;
block:
     '{' statements '}'
   ;
Functions include  function declarations, methods, getters, setters and function literals.
All functions have a signature and a body. The signature describes the formal parameters of the function, and possibly its name and return type. The body is a block statement containing the statements executed by the function. A function body of the form  => e is equivalent to a body of the form {return e;}.

If the last statement of a function is not a return statement, the statement return null; is implicitly appended to the function body.
Because Dart is optionally typed, we cannot guarantee that a function that does not return a value will not be used in the context of an expression. Therefore, every function must return a value. See the discussion around the return statement.

Quite simple?  Yeah.  But maybe this is also worth of a little analyzing and remarks.
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