A.2.5.4 Closures
[FIXME: this needs to be further subbed, but texinfo has no subsubsub]
A closure is a procedure object, generated as the value of a
lambda expression in Scheme. The representation of a closure is
straightforward — it contains a pointer to the code of the lambda
expression from which it was created, and a pointer to the environment
it closes over.
In Guile, each closure also has a property list, allowing the system to
store information about the closure. I'm not sure what this is used for
at the moment — the debugger, maybe?
— Macro: int
SCM_CLOSUREP (
SCM x)
Return non-zero iff x is a closure.
— Macro: SCM
SCM_PROCPROPS (
SCM x)
Return the property list of the closure x. The results are
undefined if x is not a closure.
— Macro: void
SCM_SETPROCPROPS (
SCM x, SCM p)
Set the property list of the closure x to p. The results
are undefined if x is not a closure.
— Macro: SCM
SCM_CODE (
SCM x)
Return the code of the closure x. The result is undefined if
x is not a closure.
This function should probably only be used internally by the
interpreter, since the representation of the code is intimately
connected with the interpreter's implementation.
— Macro: SCM
SCM_ENV (
SCM x)
Return the environment enclosed by x.
The result is undefined if x is not a closure.
This function should probably only be used internally by the
interpreter, since the representation of the environment is intimately
connected with the interpreter's implementation.