SPECIAL TOPIC:

        Built-in Functions

        A function takes zero or more arguments and returns a value.  When a
        function is called, each argument is converted to the required type
        before it is processed.  Here is the list of built-in functions
        supported in SCL:

                busidx ( name, index1 [, index2])

                        Busidx() returns a SCALD signal name for either
                        one bit of a bus or a subrange of a bus called
                        "name".  If index2 is absent then the function
                        generates a name for a single bit of the bus
                        indicated by index1.  If index2 is present then
                        the generated name is for a subrange of the bus
                        from index1 to index2.  Note that the square
                        brackets above indicate that index2 is optional.
                        They are not part of the SCL syntax.  Examples:

                            busidx("sig", 1)    ==>  "sig<1>"
                            busidx("sig", 1, 4) ==> "sig<1..4>"

                char ( x )

                        Char() returns a string with a length of one.  The
                        character in the returned string is the one whose
                        position in the collating sequence is represented by
                        the integer argument x.  For most machines, the
                        native collating sequence is ASCII. So, the returned
                        character is the ascii character whose numeric
                        equivalent is x.  This function is the inverse of
                        num().

                float ( x )

                        Float() returns its argument converted to floating
                        point type.

                int ( x )

                        Int() returns its argument converted to integer
                        type.

                len ( x )

                        Len() returns an integer count of the number of
                        characters in its string argument.

                num ( x )

                        Num() returns an integer whose value is the position
                        in the collating sequence occupied by the first
                        character of its string argument.  For ASCII (which
                        most machines use), num() returns the ASCII value of
                        a character.  This function is the inverse of
                        char().
