ConfigValue

The base trait for all configuration values.

This data structure is quite similar to those found in common JSON libraries (HOCON is a JSON superset after all).

The only exception is one special type: the ASTValue which can hold an instance of a document AST obtained from parsing text markup.

This can be useful in scenarios where substitution variables in templates or markup want to refer to other AST elements and include them into their AST tree as is.