Quick question regarding the YAML format for outputs and topics Why is there an extra nested list between the output/topic name and the tuple elements?

output:
  html:
  - - meta:
        type: "map"
        description: "Sample metadata"
    - '*.html':
        type: "file"
        description: "FastQC report"

I would expect it to be like this:

output:
  html:
    - meta:
        type: "map"
        description: "Sample metadata"
    - '*.html':
        type: "file"
        description: "FastQC report"

I'd say only @mashehu and @Júlia Mir know why

it’s to mimic the structure of the channels

tuple val(a), emit: ch_a

would be

output:
    ch_a:
        - - a: ...

while

val(a), emit: ch_a

would be

output:
    ch_a:
        - a: ...