Dotted Keys Explained

In CCL, dotted keys are literal string keys containing dots, not shorthand for nested structures.

The Core Distinction

These create different data structures:

/= Dotted key: literal string
database.host = localhost

/= Hierarchical nesting
database =
  host = localhost

The dotted-key example creates Entry("database.host", "localhost"). The hierarchical example creates Entry("database", "host = localhost"); after build_hierarchy(), it becomes {database: {host: "localhost"}}.

Access Patterns

Dotted keys use the literal string:

get_string(config, "database.host")      // ✓ Works
get_string(config, "database", "host")   // ❌ No nested object

Hierarchical data uses nested access:

get_string(config, "database", "host")   // ✓ Works
get_string(config, "database.host")      // ❌ No literal key

Best Practice: Choose One Style

/= Hierarchical (recommended)
database =
  host = localhost
  port = 5432

/= Dotted keys
database.host = localhost
database.port = 5432

/= Do not mix styles: this creates separate keys
database =
  host = localhost
database.port = 5432

Implementation Note

Some implementations provide an opt-in expand_dotted function that rewrites dotted keys into nested structures. This is experimental and tracked under the experimental_dotted_keys feature tag. Standard typed accessors (get_string, get_int, etc.) take separate path segments; they do not interpret "a.b" as a path.