Method chaining enhancements

Genero BDL version 3.10 introduced method chained calls like this:

MAIN
    DEFINE s STRING
    LET s = "ABC"
    DISPLAY s.subString(1,2).toLowerCase()
END MAIN

Starting with version 4.00, it is now possible to chain method calls, with the return value of a function:

MAIN
    DISPLAY foo().subString(1,2).toLowerCase()
END MAIN

FUNCTION foo() RETURNS STRING
    RETURN "abc"
END FUNCTION

Example using a DICTIONARY OF STRING:

MAIN
    DISPLAY foo().getLength()
    DISPLAY foo()["abc"].toUpperCase()
END MAIN

FUNCTION foo() RETURNS DICTIONARY OF STRING
    DEFINE dic DICTIONARY OF STRING
    LET dic["abc"] = "xxxx"
    LET dic["def"] = "yyyyyy"
    RETURN dic
END FUNCTION

Using built-in functions like upshift():

MAIN
    DISPLAY upshift("abc").getLength()
END MAIN

Using base.Channel:

MAIN
    DISPLAY my_open("file1").readLine()
    DISPLAY my_open("file2").readLine()
END MAIN

FUNCTION my_open(fn STRING) RETURNS base.Channel
    DEFINE ch base.Channel
    LET ch = base.Channel.create()
    TRY
        CALL ch.openFile(fn,"r")
    END TRY
    RETURN ch
END FUNCTION