Function Object Format

The old notion of a "function object" is now broken down into four different parts:

Function entry
A function entry is a structure that holds the information that we need to call a function. This is the user visible function object.

Environment
The environment is stuff that a function needs when it runs. This includes constants computed at load time and variables closed over at run time. Environment information may be allocated in the function entry structure after the required linkage information.

Entry information
This is information about a specific function entry that is occasionally referenced at run time, but need not be immediately accessible. Entry information will be either allocated in the function entry or in the environment that it points to.

Debug information
This is information about a function that isn't normally needed at run time. Debug information can be found by poking around in environment objects.

See chapter for a description of how function objects are used.