yaml Using anchors and aliases for transcluded content Creating an "Array of Dictionaries" table with YAML anchors as row identifiers

Example

    ---
    person_table:
      - &person001
        fname:  homer
        lname:  simpson
        role:   dad
        age:    33

      - &person002
        fname:  marge
        lname:  simpson
        role:   mom
        age:    34

      - &person003
        fname:  peter
        lname:  griffin
        role:   dad
        age:    34

Problem

• developer wishes to express a table structure in YAML, where each row is referenced by a compact row identifier

Solution

• use YAML anchors, by assigning an anchor identifier to each row in the table
• in YAML, reusable "transclusion identifiers" are called anchors and aliases
• in YAML, reusable "transclusion identifiers" consist of alphanumeric tokens preceeded by an ampersand or asterisk

Rationale

• YAML anchors and aliases allow for increased data normalization
• YAML anchors and aliases enforce DRY (Don't repeat yourself)
• in this example, a table structure can be designed and preserved which closely coincides with a database

Pitfalls

• YAML anchors must be declared before they can be referenced by aliases
• YAML anchors must be unique throughout the document
• failure to specify unique anchors will cause an error on yaml.load()
• not all YAML parsers reliably support anchors and aliases

See also

Stackoverflow YAML