Naked dot - accessing object fields through unqualified "." [C1]

Alexandre MAKARENKO alexandre.makarenko at
Tue Mar 24 06:14:35 PDT 2009

Naked dot

FEATURE SUMMARY: Accessing object fields through unqualified "."

MAJOR ADVANTAGE: Obsoletes attribute naming conventions.

MAJOR BENEFIT:  Makes Java programs visually more readable and eventually 
less error-prone (see ?Strict mode? in details).

To avoid name collisions and make source codes more maintainable 
developers either hold with a convention for attribute names or prefix 
members by ?this.? when refer to. Any naming convention, since not a part 
of the language, offers only a weak distinction between local variable and 
object field. Moreover it introduces extra characters and makes the source 
code not very natural. Using ?this.? is absolutely safe but makes the 
source code too much heavy. 
Assessing object fields through unqualified ?.? may be an elegant 
trade-off between readability and strictness.

MAJOR DISADVANTAGE:  May look assemblish.

Use "this.aField" or m_aField, or _aField, or any other naming convention 
to distinguish between local variables and object fields.

public class Point
    public Point( double x, double y )
        .x = x; // compiles like this.x = x;
        .y = y; // compiles like this.y = y;
    private double x, y;

During the name lookup process a package-less ?.? will be considered as 
?this.?. So that
?.fieldName? will be equivalent to ?this.fieldName?.

COMPILATION: The compiler detects unqualified dots and (if not a start of 
floating point value) inserts an imaginary ?this?.

TESTING:  Not relevant

LIBRARY SUPPORT: Not relevant.

REFLECTIVE APIS:  Not relevant

OTHER CHANGES: Not relevant

Weak mode (default). Attribute name look-up is carried out as it is 
mentioned in the current language specification. For example
public class Point
    public move( double dx, double dy )
        .x += dx; // resolves .x to this.x
         y += dy; // resolves  y to this.y 
    private double x, y;
Strict mode  (optional). For enterprises who would like to enforce 
in-house coding styles, there may be a kind of -XStrictMemberAccess 
compiler option. In this case the unqualified attribute references will 
fail to compile. For example

public class Point
    public move( double dx, double dy )
        .x += dx; // only local and static variables may
                  // be referred to without ?.? 
         y += dy; // compile time error: unknown y 
    private double x, y;
Ascending source level compatibility (in Weak mode) with existing Java 
Absolute binary compatibility with all existing Java software.
Disassemblers may produce both ?this.? and ?.? (since they are 

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