Handling a YAML Stream file with multiple types of models

[ronaldtse]

Specifically, we want to handle this kind of file:

• Parse the "multi-content YAML" file which includes multiple localized concepts with the main concept in the same file glossarist/glossarist-ruby#132

This is used in ISO 5843-6:2025.

The setup of "concept/.yaml + localized_concepts/.yaml" is way too complicated for management purposes from the filesystem. This approach is not suitable for management as source code.

For example, this would already work:

---
data:
  dates:
    - date: 2023-01-01T00:00:00.000+00:00
      type: accepted
  definition:
    - content: process by which atmospheric gases absorb electromagnetic radiation
  id: '1-EN'
  sources:
    - origin:
        ref: ISO 2533:1975
        clause: 3.2.1
      type: authoritative
  terms:
    - designation: absorption, atmospheric
      normative_status: preferred
      type: expression
  language_code: eng
dateAccepted: 2023-01-01T00:00:00.000+00:00
id: 3a75582e-699c-4e08-b26a-3ebd6fb00101
status: 3a75582e-699c-4e08-b26a-3ebd6fb00102
---
data:
  dates:
    - date: 2023-01-01T00:00:00.000+00:00
      type: accepted
  definition:
    - content: processus par lequel les gaz atmosphériques absorbent le rayonnement électromagnétique
  id: '1-FR'
  sources:
    - origin:
        ref: ISO 2533:1975
        clause: 3.2.1
      type: authoritative
  terms:
    - designation: absorption atmosphérique
      normative_status: preferred
      type: expression
  language_code: fra
dateAccepted: 2023-01-01T00:00:00.000+00:00
id: b4e76f2a-9d3c-4a1f-8e5b-6c0d9f1a2b83
status: valid
---
data:
  dates:
    - date: 2023-01-01T00:00:00.000+00:00
      type: accepted
  definition:
    - content: процесс поглощения атмосферными газами электромагнитного излучения
  id: '1-RU'
  sources:
    - origin:
        ref: ISO 2533:1975
        clause: 3.2.1
      type: authoritative
  terms:
    - designation: атмосферное поглощение
      normative_status: preferred
      type: expression
  language_code: rus
dateAccepted: 2023-01-01T00:00:00.000+00:00
id: 3a75582e-699c-4e08-b26a-3ebd6fb00103
status: valid
---
data:
  dates:
    - date: 2023-01-01T00:00:00.000+00:00
      type: accepted
  definition:
    - content: prozess bei dem atmosphärische Gase elektromagnetische Strahlung absorbieren
  id: '1-DE'
  sources:
    - origin:
        ref: ISO 2533:1975
        clause: 3.2.1
      type: authoritative
  terms:
    - designation: atmosphärische Absorption
      normative_status: preferred
      type: expression
  language_code: deu
dateAccepted: 2023-01-01T00:00:00.000+00:00
id: 3a75582e-699c-4e08-b26a-3ebd6fb00104
status: valid
---
data:
  identifier: '1'
  localized_concepts:
    eng: 3a75582e-699c-4e08-b26a-3ebd6fb00101
    fra: 3a75582e-699c-4e08-b26a-3ebd6fb00102
    rus: 3a75582e-699c-4e08-b26a-3ebd6fb00103
    deu: 3a75582e-699c-4e08-b26a-3ebd6fb00104
dateAccepted: 2023-01-01T00:00:00.000+00:00
id: 3a75582e-699c-4e08-b26a-3ebd6fb00100
status: valid

I think there are 2 ways:

1. We declare at the model level that "the first 4 things will be localized concepts, the 5th is a concept" (or the other way round since it would be easier: the first is a concept and the rest are localized concepts).
2. Somehow we define it in the YAML file itself, e.g. the first document is a "meta" document that points to the types/models of each following document
3. We define the type in each document stating what class it is (e.g. _lutaml_model: my_class) but I don't know how we can tie them together (i.e. concepts "has" localized concepts.