avoid duplicates with pathconvert and mappers

[Patrick Martin]

Hello,

I have a folder looking like:
folder1/file-1.txt
folder1/file-2.txt
folder2/file-1.txt
folder2/file-3.txt

i'd like to list the file ids: 1,2,3.

Trying with pathconvert:
        <pathconvert property="id.list" pathsep=",">
            <fileset dir="${mydir}" includes="folder*/*.txt" />
            <chainedmapper>
                <flattenmapper />
                <regexpmapper from="file-([^-]+).txt" to="\1" />
            </chainedmapper>
        </pathconvert>

However, the id 1 gets duplicated. Is there anyway I can avoid this dupe?

The pathconvert attribute preserveduplicates="false" does not bring any
help here.
I also tried the uniq filter in a filtermapper, without luck.

Thank you in advance,

Patrick