At 10:08 AM 12/3/99 -0800, Mark Leisher wrote:
>I have a web page showing the results from tests of two (soon to be three)
>freely available bidi reordering packages for Unicode text. The text I used
>for the tests as well as the test programs I wrote for all three are
available
>as well:
>
> http://crl.nmsu.edu/~mleisher/ucdata.html
>
>Please feel free to donate additional tests/code, point out problems, or make
>comments.
The really interesting question is how do these algorithms compare with the
official bidi reference implementations published by the Unicode Consortium.
The Unicode sample code is availabe at
http://www.unicode.org/unicode/reports/tr9/BidiReferenceCpp/
http://www.unicode.org/unicode/reports/tr9/BidiReferenceCpp/
The Technical report states:
>1 Reference Code
>
>There are two versions of BIDI reference code available. Both have been
tested to produce identical results. One version is written in Java, while
the other is written in C++. The Java version is designed to closely follow
the steps of the algorithm as described in this report. The C++ code is
designed to show one of the optimization methods that can be applied to the
algorithm, using a state table for one phase.
>
It is very important to note that any implementations that don't match the
published algorithm, as evidenced by yielding different results than the
reference implementations, are *not conformant*.
Since the whole purpose of the bidi algorithm is to allow *writers* to
predict the ordering of their text on the *readers'* screen, adherence to
the conformance requirements is crucial.
The published reference implementations were tested exhaustively up to
sequences of length 6 against each other, and stochastically for much
longer sequences, with special prefixes used to force the implemenations to
hit the maximum nesting level during some portion of the tests.
I would encourage Mark to test his algorithms exhaustively against the
reference code and report his results here.
For more details on bidi and the conformance requirements read the report at:
http://www.unicode.org/unicode/reports/tr9/
A./
This archive was generated by hypermail 2.1.2 : Tue Jul 10 2001 - 17:20:56 EDT