Explanation of attrs item in rules

[moritz-gross]

@daisy/mathcat-translators

Some rules use an item called attrs, usually nested within intent.

here is a full example

-
  name: geometry-ray
  tag: mover
  match:
    - "*[2][self::m:mo][.='→'] and"  # u2192
    - "*[1][self::m:mrow][count(*)=3 and "
    - "     *[1][self::m:mi and translate(., 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', '') = ''] and"
    - "     *[2][self::m:mo and (.='\u2062' or .='\u2063')] and"
    - "     *[3][self::m:mi and translate(., 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', '') = '']"
    - "                  ]"
  replace:
  - intent:
      name: "ray"
      attrs: "data-intent-property='concat(data-intent-property, \":prefix:\")'"
      children:
      - x: "*[1]/*[1]"
      - x: "*[1]/*[3]"

I could not find any documentation on this. I assume it stands for "attributes"?
My questions include:

• what kinds of attributes can be set here?
• can it only be used within intent ?
• the main use is data-intent-property I guess?
• ...