FilePath globbing does not support curly brackets glob with only one entry, trailing comma

[dtrudg]

I'm using curly bracket globbing to create a channel emitting multiple files where the files are listed in a string parameter separated by commas.

While playing with this I noticed that Nextflow doesn't recognize curly bracket globs with a single entry and trailing comma. These are actually valid glob patterns. e.g.:

{alice.txt,}

... is a valid glob pattern matching only alice.txt

It's unusual to have one of these, but I believe nextflow should support them as they are valid. This issue has come up in other software e.g. https://issues.jboss.org/browse/TORQUE-128

I believe that in FileHelper class:

static final public Pattern GLOB_CURLY_BRACKETS = Pattern.compile(/(.*)(\{.+,.+\})(.*)/)

...correct regex should allow trailing ',' inside the brackets....

static final public Pattern GLOB_CURLY_BRACKETS = Pattern.compile(/(.*)(\{.+,.*\})(.*)/)

[pditommaso]

It makes sense.

[pditommaso]

If so, also the following should be recognised at valid glob:

{,alice.txt}
{,}

@dctrud What do you think?

[dtrudg]

@pditommaso well they are valid with bash/ls. The second one evaluates to nothing...

dtrudgian@rop504388:~/test
10:22 PM $ ls {,alice.txt}
alice.txt
dtrudgian@rop504388:~/test
10:22 PM $ ls {,}
alice.txt mary.txt  test      testdir

Not sure whether they are valid for the java.nio globbing? I had a look online and couldn't find any complete definition of the globbing syntax that's valid for it.

[pditommaso]

Yes, it is. I've added a couple of tests for that. Thanks.