Extending RecordSchemas?

CWL Questions
1

Is it possible to extend a record schema?

For example, let’s say I have the base schema ‘contig’ which has the attributes - chromosome, start and end, that I have added to a file called contig_basic.yaml. Let’s assume I use this schema in a tool called bedtools_basic.cwl

type: record
name: contig

fields:
  chromosome:
    label: chromosome
    doc: |
      The name of the chromosome
    type: string
  start:
    label: start position
    doc: |
      The start position of the chromosome of the region
    type: int?
  end:
    label: end position
    doc: |
      The end position of the chromosome of the region
    type: int?

Let’s say now, for another tool called bedtools_advanced, I want to have a schema that is identical to the contig schema but with a boolean attribute is_alt_contig which is set to true for ‘ALT’ contigs. Is there a way for me to import the attributes from contig_base.yaml and then extend this with my additional field?

The best I can achieve so far is:

type: record
name: contig_advanced

fields:
  # Import each field from the basic schema
  - $import: "contig_base.yaml#contig/chromosome"
  - $import: "contig_base.yaml#contig/start"
  - $import: "contig_base.yaml#contig/end"
  # Extend the basic schema with the field 'is_alt_contig'
  - name: is_alt_contig
    label: is alt contig
    doc: |
      Is this contig an alt contig
    type: boolean

Ideally I’d be able to do something like

type: record
name: contig_advanced

fields:
  # Import entire schema
  - { "$import": "contig_base.yaml#contig" }
  # Extend the basic schema with the field 'is_alt_contig'
  - name: is_alt_contig
    label: is alt contig
    doc: |
      Is this contig an alt contig
    type: boolean