NOTES

A "community" - "semantics" pair store.

A community can contain up to 'parameterisation' element, called '*'.

Number is more-specific to a '*'.

Each community is linked to a 'function', and a dictionary of 'parameters'.

Avoid that looking up a community integer, can result in multiple semantic meanings.

Per 'function' the set of available parameters will differ.
    
    "2914:%i": {
      "__comment": "ASN based single prepending",
      "function": "prepend",
      "parameters": {
        "count": 1,
        "target_asn": "%i",
      }
    }

We need to define the following functions:

    - prepend
        - property: action
        - prepend_count
        - to: asn_grouping
        - location
    - no_export
        - property: action
        - to: asn_grouping
        - location
    - manipulate_lp_relative
        - property: action
        - lp_value
        - location
    - manipulate_med
        - property: action
        - med_value
        - to: asn_grouping
    - blackhole
        - property: action
        - location
    - received
        - property: informational
        - from: asn_grouping
        - location

We need to define the following common parameters:

    - location
        * city, country, continent, global
        types: "country", "msa", "unm49"
        if the value exists in the mapping table, use that instead.

        magic values: "not_here" and "here":
            'here' means the country, msa, region (depends on the type) in
                   which the route announcement was received.
            'not_here' means any countries, msa, regions (depends on the type)
                    outside the location where the route was received.

    - constraints:
        type: "class", "target_list"
        * individual asns or classes like 'customers'

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CODS defines the functions in a central schema

Users define their own schema in JSON or YAML.

Libaries and example programs are provided by CODS.

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scaffold outputs:

    - comm2name tool
    - search4comm tool
    - meta schema for function & parameters 
    - schema for routing policy itself