2swap cons
2 +loop
- depth 2- fixnum-type 2swap cons
+ depth 2- 2/ fixnum-type 2swap cons
;
-: make-continuation
+: make-continuation ( -- continuation true-obj )
+ \ true-obj allows calling code to detect whether
+ \ it is being called immediately following make-continuation
+ \ or by a restore-continuation.
cons-param-stack
cons-return-stack
cons drop continuation-type
+
+ true boolean-type
;
: continuation->pstack-list
: continuation->rstack-list
drop pair-type cdr ;
-: restore-param-stack ( continuation -- obj_stack continuation )
+: stack-list-len ( stack-list -- n )
+ car drop
+;
+: restore-param-stack ( continuation -- obj_stack )
continuation->pstack-list
2dup >R >R
( Allocate stack space first using psp!,
then copy objects from list. )
- car drop
+ car drop 2*
object-stack-base @ psp0 + + psp!
R> R> 2dup cdr
2swap
- car drop 2- 0 swap do
+ stack-list-len 1- 0 swap do
2dup car
- PSP0 object-stack-base @ + i + 2 + !
- PSP0 object-stack-base @ + i + 1 + !
+ PSP0 object-stack-base @ + i 2* + 2 + !
+ PSP0 object-stack-base @ + i 2* + 1 + !
cdr
- -2 +loop
+ -1 +loop
2drop
+;
+
+: restore-return-stack ( continuation -- )
+
+ continuation->rstack-list
+
+ 2dup cdr 2swap stack-list-len ( list n )
+
+ dup RSP0 + RSP! \ expand return stack to accommodate entries
+
+ ( list n )
+ 1- \ initial offset n-1
+ 0 \ final offset 0
+ swap
+ do
+ 2dup cdr 2swap car drop
+ RSP0 i 1+ + !
+ -1 +loop
+
+ 2drop
;
-: restore-continuation
- \ TODO: replace current parameter and return stacks with
- \ contents of continuation object.
+: restore-continuation-with-arg ( continuation obj -- )
+
+ >R >R \ Store obj on return stack
+
+ 2dup >R >R \ Store copy of continuation on return stack
+
+ restore-param-stack
+
+ R> R> \ Pop continuation from return stack
+
+ R> R> \ Pop obj from return stack
+
+ 2swap
+
+ false boolean-type \ Add flag signifying continuation restore
+
+ 2swap
+
+ restore-return-stack
;
\ }}}
endof
continuation-type of
- \ TODO: Apply continuation
+ 2swap
+ nil? if
+ except-message: ." Continuations expect exactly 1 argument."
+ recoverable-exception throw
+ then
+
+ 2dup cdr
+
+ nil? invert if
+ except-message: ." Continuations expect exactly 1 argument."
+ recoverable-exception throw
+ then
+
+ 2drop car
+
+ restore-continuation-with-arg
endof
except-message: ." object '" drop print ." ' not applicable." recoverable-exception throw
symbol-type istype? if true exit then
compound-proc-type istype? if true exit then
port-type istype? if true exit then
+ continuation-type istype? if true exit then
false
;
\ }}}
-xxxx
-
\ ---- Loading files ---- {{{
: load ( addr n -- finalResult )