create cdr-cells scheme-memsize allot
create cdr-type-cells scheme-memsize allot
-variable gc-enabled
-false gc-enabled !
-
-: gc-enabled?
- gc-enabled @ ;
-
create nextfrees scheme-memsize allot
:noname
scheme-memsize 0 do
nextfree !
nextfree @ scheme-memsize >= if
- gc-enabled? if
- collect-garbage
- then
+ collect-garbage
then
nextfree @ scheme-memsize >= if
cdr-cells + !
;
+variable object-stack-base
+: init-object-stack-base
+ depth object-stack-base ! ;
+
: nil 0 nil-type ;
: nil? nil-type istype? ;
\ }}}
+\ ---- Continuations ---- {{{
+
+: cons-return-stack ( -- listobj )
+ rsp@ 1- rsp0 = if
+ nil exit
+ then
+
+ nil rsp@ 1- rsp0 do
+ i 1+ @ fixnum-type 2swap cons
+ loop
+;
+
+: cons-param-stack ( -- listobj )
+ nil
+
+ depth 2- object-stack-base @ = if
+ exit
+ then
+
+ depth 2- object-stack-base @ do
+ PSP0 i + 1 + @
+ PSP0 i + 2 + @
+
+ 2swap cons
+ 2 +loop
+;
+
+: make-continuation
+
+ cons-param-stack
+ cons-return-stack
+ cons drop continuation-type
+;
+
+: restore-continuation
+ \ TODO: replace current parameter and return stacks with
+ \ contents of continuation object.
+;
+
+\ }}}
+
\ ---- Primitives ---- {{{
: make-primitive ( cfa -- )
\ ---- Garbage Collection ---- {{{
-variable gc-stack-depth
-
-: enable-gc
- depth gc-stack-depth !
- true gc-enabled ! ;
-
-: disable-gc
- false gc-enabled ! ;
-
: pairlike? ( obj -- obj bool )
pair-type istype? if true exit then
string-type istype? if true exit then
console-i/o-port obj@ gc-mark-obj
global-env obj@ gc-mark-obj
- depth gc-stack-depth @ do
+ depth object-stack-base @ do
PSP0 i + 1 + @
PSP0 i + 2 + @
include scheme-primitives.4th
- enable-gc
-
+ init-object-stack-base
s" scheme-library.scm" load 2drop
-
- disable-gc
\ }}}
: repl
empty-parse-str
- enable-gc
+ init-object-stack-base
\ Display welcome message
welcome-symbol nil cons global-env obj@ eval 2drop
throw false
endcase
until
-
- disable-gc
;
forth definitions