Library Conventions

Multimethod Naming

All multimethods end in *. Often there is a convenient version of a function intended for external use with flexible arglists, such as instance, whose arities are:

(instance tableabl)
(instance tableable m)
(instance connectable tableable m)
(instance connectable tableable k v & more)

The convenient function parses the args and eventually calls the underlying method*, e.g. instance*:

(instance* connectable tableable original-map current-map key-xform metta)

When you're extending Toucan 2, implement a method*, when you're using Toucan 2, call a function.

Parameter Order

connectable, tableable, queryable, options, and the like are common parameters that are used all over the codebase. To keep things predictable, the following parameter order conventions are used everywhere:

• If connectable is an arg, it is almost always the (sometimes optional) first arg. Exceptions are functions like select-pks-set that place special meaning on the first arg.
• If tableable is an arg, it follows directly after connectable, i.e. is the second arg.
• Anything that takes a tableable should also take a connectable.
• If options is an arg, it is always the last argument.