return

return

exit from a function

Syntax

return
return E

Description

This command is used to exit from a procedure/function. The latter form returns the value of the expression E to the user. As a safety measure all return s in a function/procedure must be of the same kind: either they all return a value (function) or none returns a value (procedure). To exit from a loop see break .

Example

/**/  Define Rev(L) -- reverse a list
/**/    If len(L) < 2 Then Return L; EndIf;
/**/    M := Rev(Tail(L)); -- recursive function call
/**/    append(ref M, L[1]);
/**/    Return M;
/**/  EndDefine;

/**/  Rev([1,2,3,4]);
[4, 3, 2, 1]

----  mixing function/procedure returns is not allowed
-- /**/  Define AFailingExample(X)
-- /**/    If X=1 Then Return 123456;
-- /**/    Else Return; -- .....  --> !!! ERROR !!!
 ERROR: Inside a function definition all Return statements must be
  either with or without an expression
    Else Return;
         ^^^^^^^

See Also

break
define