X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=src%2Fscheme.4th;h=48c363a9a1fda82c6031b189a4a9a2c12f728336;hb=899e3f7a10cbb8ecd03aa2dfe3ad08bf4638a324;hp=d6dccd1c7d91aaf44c81693b7e4cb9005d519a76;hpb=3f60507c407dc22a19b4539d08cc926c54141653;p=scheme.forth.jl.git

diff --git a/src/scheme.4th b/src/scheme.4th
index d6dccd1..48c363a 100644
--- a/src/scheme.4th
+++ b/src/scheme.4th
@@ -39,6 +39,7 @@ make-type pair-type
 make-type symbol-type
 make-type primitive-proc-type
 make-type compound-proc-type
+make-type continuation-type
 make-type port-type
 : istype? ( obj type -- obj bool )
     over = ;
@@ -62,7 +63,7 @@ variable nextexception
 make-exception recoverable-exception
 make-exception unrecoverable-exception
 
-: throw reset-term throw ;
+: throw reset-term cr throw ;
 
 \ }}}
 
@@ -75,6 +76,12 @@ create car-type-cells scheme-memsize allot
 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
@@ -90,7 +97,9 @@ variable nextfree
     nextfree !
 
     nextfree @ scheme-memsize >= if
-        collect-garbage
+        gc-enabled? if
+            collect-garbage
+        then
     then
 
     nextfree @ scheme-memsize >= if
@@ -1661,6 +1670,10 @@ parse-idx-stack parse-idx-sp !
                ['] evaluate-eproc goto
         endof
 
+        continuation-type of
+          \ TODO: Apply continuation
+        endof
+
         except-message: ." object '" drop print ." ' not applicable." recoverable-exception throw
     endcase
 ;
@@ -1909,6 +1922,9 @@ parse-idx-stack parse-idx-sp !
 : printcomp ( primobj -- )
     2drop ." <compound procedure>" ;
 
+: printcont ( primobj --)
+    2drop ." <continuation>" ;
+
 : printnone ( noneobj -- )
     2drop ." Unspecified return value" ;
 
@@ -1927,6 +1943,7 @@ parse-idx-stack parse-idx-sp !
     pair-type istype? if ." (" printpair ." )" exit then
     primitive-proc-type istype? if printprim exit then
     compound-proc-type istype? if printcomp exit then
+    continuation-type istype? if printcont exit then
     none-type istype? if printnone exit then
     port-type istype? if printport exit then
 
@@ -1937,9 +1954,6 @@ parse-idx-stack parse-idx-sp !
 
 \ ---- Garbage Collection ---- {{{
 
-variable gc-enabled
-false gc-enabled !
-
 variable gc-stack-depth
 
 : enable-gc
@@ -1949,9 +1963,6 @@ variable gc-stack-depth
 : disable-gc
     false gc-enabled ! ;
 
-: gc-enabled?
-    gc-enabled @ ;
-
 : pairlike? ( obj -- obj bool )
     pair-type istype? if true exit then
     string-type istype? if true exit then
@@ -2018,9 +2029,7 @@ variable gc-stack-depth
 ;
 
 :noname
-    ." GC! "
-
-    trace
+    \ ." GC! "
 
     gc-unmark
 
@@ -2038,7 +2047,7 @@ variable gc-stack-depth
 
     gc-sweep
 
-    ." (" gc-count-marked . ." pairs marked as used.)" cr
+    \ ." (" gc-count-marked . ." pairs marked as used.)" cr
 ; is collect-garbage
 
 \ }}}
@@ -2054,12 +2063,12 @@ variable gc-stack-depth
 
     begin
         \ DEBUG
-        bold fg blue ." READ from " 2over drop . ." ==> " reset-term
+        \ bold fg blue ." READ from " 2over drop . ." ==> " reset-term
 
         2over read-port ( port res obj )
 
         \ DEBUG
-        2dup print cr
+        \ 2dup print cr
 
         2dup EOF character-type objeq? if
             2drop 2swap close-port
@@ -2078,7 +2087,11 @@ variable gc-stack-depth
 
     include scheme-primitives.4th
 
+    enable-gc
+
     s" scheme-library.scm" load 2drop
+
+    disable-gc
     
 \ }}}
 
@@ -2109,7 +2122,7 @@ variable gc-stack-depth
     enable-gc
 
     \ Display welcome message
-    \ welcome-symbol nil cons global-env obj@ eval 2drop
+    welcome-symbol nil cons global-env obj@ eval 2drop
 
     begin
         ['] repl-body catch
@@ -2120,6 +2133,8 @@ variable gc-stack-depth
             throw false
         endcase
     until
+
+    disable-gc
 ;
 
 forth definitions