Weighing Bash Builtins

I don't know about other third-party Bash builtins, so I am not sure how well my third-party builtin will be accepted.

Builtins have the following advantages:

• Fast C code runs in process for efficient execution.
• Allows calls from C code to script functions (callbacks).

Builtins may have some downsides:

• Bash garbage-collection only handles Bash variable types
• Calling script functions from a builtin requires using an unpublished internal Bash function.