Re: Unicode and Java Questions

From: John W Kennedy (
Date: Thu Oct 02 2008 - 21:36:44 CDT

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    On Oct 2, 2008, at 7:37 PM, Matt Chu wrote:
    > 1) There DOES exist language-dependent string equivalence, as well
    > as Java's built-in language-independent string equivalence. That is,
    > the follow situation exists:
    > x = "\uXXXX";
    > y = "\uYYYY";
    > if (locale == A) then x == y else x != y


    In the first place, "x == y" in Java means that x and y are the same
    object. In the second place, the definition of x.equals(y) is not
    locale-dependent; it means only that the two strings have the same
    sequence of 16-bit UTF-16 codes. (In other words, if you want equals()
    and hashCode() to work, you /will/ need some kind of normalization.)

    > 2) Given that (1) is true and .equals changes based on locale, then
    > doesn't that mean I have to override .hashCode in order to maintain
    > the Java equals/hashcode contract (i.e. make sure my Collections
    > don't break)?

    And all this fails, because (1) is not true.

    John W Kennedy
    "Compact is becoming contract,
    Man only earns and pays."
       -- Charles Williams.  "Bors to Elayne:  On the King's Coins"

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