🚀 go-pugleaf

Adding closures to a shallow-binding interpreter.

I have a shallow-binding interpreter, which has no lexical closure. 
My attempts to implement (function ) have been only partially succesful,
am I right in assuming that this is impossible?

So far my best attempt has been the following:

(defmacro my-function (fn)
`'(lambda (&rest f-args)
	((lambdaq ,(bound-oblist)
		(apply fn f-args))
	,@(mapcar 'eval (bound-oblist)))))

I should explain that in in the interpreter:

	lambdaq forms do not evaluate their arguments, 

	(bound-oblist) is a function that returns a list of all the symbols
	with bound values.

	symbols have only one value which can be a function 

; Simple test case:
(setq free 67)
(setq my-test (my-function (lambda (a) (cons a free))))
(print (my-test 12))
(setq free 88)
(print (my-test 12))

; produces:

; (12 . 67)
; (12 . 67)

The simple cases work ok, however  the following :

(setq free 67)
(setq my-test2 (my-function (lambda () (print free)(setq free 4))))
(my-test2)
(my-test2)

produces:
; 67
; 67

Where CLtL2 would want it to produce 67 4.

It is obvious why it cannot, but is there any way to do it?


Thanks in advance,

Bill

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 Bill Birch             	|	B.Birch@uk03.bull.co.uk
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