* core/callcc.c: bug in continuations. needed to send back self ra…

…ther than `cl` from the yield.

 * test: a few tests of continuations.

core/callcc.c

@@ -24,7 +24,8 @@ PN potion_continuation_yield(Potion *P, PN cl, PN self) {
 #endif
 
   if ((PN)sp1 != cc->stack[0]) {
-    fprintf(stderr, "** TODO: continuations which switch stacks must be rewritten.\n");
+    fprintf(stderr, "** TODO: continuations which switch stacks must be rewritten. (%p != %p)\n",
+      sp1, (void *)(cc->stack[0]));
     return PN_NIL;
   }
 
@@ -50,9 +51,9 @@ PN potion_continuation_yield(Potion *P, PN cl, PN self) {
            "mov 0x30(%%rbx), %%r14;"
            "mov 0x38(%%rbx), %%r15;"
            "mov 0x18(%%rbx), %%rbx;"
-           "leave; ret"
+           "leaveq; retq"
            :/* no output */
-           :"r"(cl), "r"(start), "r"(end), "r"(cc->stack)
+           :"r"(cc), "r"(start), "r"(end), "r"(cc->stack)
            :"%rax", "%rsp", "%rbx"
           );
 #else
@@ -73,14 +74,14 @@ PN potion_continuation_yield(Potion *P, PN cl, PN self) {
            "mov 0xc(%%esi), %%esi;"
            "leave; ret"
            :/* no output */
-           :"r"(cl), "r"(start), "r"(end), "r"(cc->stack)
+           :"r"(cc), "r"(start), "r"(end), "r"(cc->stack)
            :"%eax", "%esp", "%ebp", "%esi"
           );
 #endif
 #else
   fprintf(stderr, "** TODO: callcc does not work outside of X86.\n");
 #endif
-  return cl;
+  return self;
 }
 
 PN potion_callcc(Potion *P, PN cl, PN self) {

core/pn-scan.rl

@@ -58,7 +58,7 @@
   path        = "/" ("/" | utfw)+;
   query       = "?" eats message;
   querypath   = "?" eats path;
-  comment     = "#"+ (utf8 - newline)*;
+  comment     = "#"+ (utf8 - newline)* newline?;
 
   nil         = "nil";
   true        = "true";

test/flow/callcc.pn

@@ -0,0 +1,9 @@
+names = ("Freddie", "Herbie", "Ron", "Max", "Ringo")
+goto = here
+name = names pop
+(name, "\n") join print
+if (name != "Ron"): goto ().
+# Ringo
+# Max
+# Ron
+# nil

test/flow/except.pn

@@ -0,0 +1,55 @@
+Exception =
+  class (msg, mark):
+    /message = msg
+    /mark = mark
+    /ignored = false.
+
+Exception resume = ():
+  /ignored = true
+  "RESUMING\n" print
+  m = /mark
+  m ().
+
+SCOPES = ()
+
+throw = (msg):
+  e = Exception (msg, here)
+  if (! e /ignored):
+    s = SCOPES last
+    c = s (0), s (0) = e
+    c ().
+  nil.
+
+try = (block, catch):
+  cc = ()
+  c = here
+  if (! cc (0)):
+    cc push (c)
+    SCOPES push (cc)
+    block ()
+  . else:
+    catch (SCOPES last (0)).
+  .
+
+1 to 2 (x):
+  try (:
+    "TRY\n" print
+    if (x == 1):
+      throw ("TRY ERROR!\n").
+    "SUCCESS\n" print.
+
+    (e):
+      e /message print
+      e resume.
+  )
+.
+
+nil
+
+# TRY
+# TRY ERROR!
+# RESUMING
+# SUCCESS
+# TRY
+# SUCCESS
+# nil