DSL-2 Named output channels

[zanieb]

Named output channels in DSL-2

Hi! I'd like if, instead of accessing output channels from import processes in DSL2 as a list, the output channels could be accessed by a map.

Usage scenario

You have a process with multiple output channels e.g.

    output:
    set val(sample_name), file('*_trimmed.fastq')
    set val('trimmed'), file('*_trimmed.fastq')
    file '*.log'

Accessing these as process_x[0], [1], [2].. is not clear what is being accessed.

Alternatively

    output:
    set val(sample_name), file('*_trimmed.fastq') as named_fastq
    set val('trimmed'), file('*_trimmed.fastq') as flagged_fastq
    file '*.log' as logs

Accessing these as process_x['named_fastq'], process_x['logs']

Suggest implementation

• Store all outputs in a list as before
• Also store all named outputs in a map
• Add a keyword to define the name of an output (perhaps reuse into or use as)

[pditommaso]

Yes, I was brainstorming on something similar. Like the idea of using as to associate a name to the output.

[pditommaso]

Closed in favour of #1290.