Support slashy interpolated strings

[VasLem]

So I have this regex written in Groovy, that gets all the FASTA files from a directory:

output = file(sample_dir).listFiles().findAll{ it.getName() =~ /${sample_name}.*\.f(?:ast)?[qa](?:\.gz)?/ }

Nextflow server complains about the slashy part, probably that is not supported, as described here . How am I supposed to write this Regex in a non slashy way?

[bentsherman]

Looking at the rules for slashy strings in Groovy, you might be able to simply replace the slashes with double quotes, but I'm not sure. If other things need to be escaped it could get quite ugly.

Can you try with double quotes and let me know if it works? Meanwhile I will do some testing. I might be able to preserve support for this kind of slashy string, especially if it is more convenient than the double-quoted string

[pditommaso]

What's the rationale to not supporting slashy string with variable interpolation?

[bentsherman]

I think early on I was concerned that it would be too complicated to support, but on further review I don't think that should be an issue

However I would like to review the exact advantages it provides over a double-quoted string. I'm concerned about having too many different kinds of strings and confusing people

[pditommaso]

Slashy strings are useful because there is no need to escape backslashes when writing regex and patterns. If we remove shell: it may be useful to keep slashy strings

[bentsherman]

@VasLem to replace the slashy string with double quotes, I think you only need to escape the backslashes. Here is a minimal example that you can test:

sample_id = 'SRA001'
files = [
    'SRA001.fastq'      : true,
    'SRA001.fastq.gz'   : true,
    'SRA001.fq'         : true,
    'SRA001.fq.gz'      : true,
    'SRA001.fasta'      : true,
    'SRA001.fasta.gz'   : true,
    'SRA001.fa'         : true,
    'SRA001.fa.gz'      : true,
    'SRA002.fa.gz'      : false,
]

files.each { file, result ->
    assert result == !!(file =~ /${sample_id}.*\.f(?:ast)?[qa](?:\.gz)?/)
    assert result == !!(file =~ "${sample_id}.*\\.f(?:ast)?[qa](?:\\.gz)?")
}

So that should solve your immediate problem with the language server.

I am testing support for dynamic slashy strings in #51 but it is not working yet. If the only advantage of slashy string is not escaping backslashes, I'm not sure it's worth supporting. Also I don't see how it's related to the shell block