From 480de114963ecee700ece5b8793916726c04b9ab Mon Sep 17 00:00:00 2001
From: Peter Mikkelsen <peter@pmikkelsen.com>
Date: Fri, 16 Jul 2021 15:25:01 +0000
Subject: Replace the C repl with one written in prolog :)

---
 builtins.c | 69 ++++++++++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 47 insertions(+), 22 deletions(-)

(limited to 'builtins.c')

diff --git a/builtins.c b/builtins.c
index 369ac92..bde52fd 100644
--- a/builtins.c
+++ b/builtins.c
@@ -60,6 +60,8 @@ BuiltinProto(builtingetchar);
 BuiltinProto(builtinpeekchar);
 BuiltinProto(builtinputchar);
 BuiltinProto(builtincharcode);
+BuiltinProto(builtinchoicestacksize);
+BuiltinProto(builtincollectgarbage);
 
 int compareterms(Term *, Term *);
 
@@ -169,6 +171,10 @@ findbuiltin(Term *goal)
 		return builtinputchar;
 	if(Match(L"char_code", 2))
 		return builtincharcode;
+	if(Match(L"$choicestack_size", 1))
+		return builtinchoicestacksize;
+	if(Match(L"$collect_garbage", 0))
+		return builtincollectgarbage;
 
 	return nil;
 }
@@ -569,37 +575,30 @@ int
 builtinthrow(Term *goal, Binding **bindings, Module *module)
 {
 	USED(bindings);
+	USED(module);
 
 	Term *ball = goal->children;
 
-	print("Throwing: %S\n", prettyprint(ball, 0, 0, 0, module));
 	Goal *g;
 	for(g = goalstack; g != nil; g = g->next){
 		if(g->catcher == nil)
 			continue;
 
 		if(unify(g->catcher, ball, bindings)){
-			if(g->goal == nil){
-				/* As soon as we have print facilities as builtins, we can avoid this by having the protector frame have a unhandled exception handler*/
-				print("Unhandled exception: %S\n", prettyprint(ball, 0, 0, 0, module));
-				exits("exception");
-				return 0;
-			}else{
-				goalstack = g->next;
-				Goal *newgoal = gmalloc(sizeof(Goal));
-				newgoal->goal = copyterm(g->goal, nil);
-				newgoal->module = module;
-				newgoal->catcher = nil;
-				newgoal->next = goalstack;
-				goalstack = newgoal;
-				applybinding(newgoal->goal, *bindings);
-
-				Choicepoint *cp = choicestack;
-				while(cp != nil && cp->id >= goal->clausenr)
-					cp = cp->next;
-				choicestack = cp;
-				return 1;
-			}
+			goalstack = g->next;
+			Goal *newgoal = gmalloc(sizeof(Goal));
+			newgoal->goal = copyterm(g->goal, nil);
+			newgoal->module = g->module;
+			newgoal->catcher = nil;
+			newgoal->next = goalstack;
+			goalstack = newgoal;
+			applybinding(newgoal->goal, *bindings);
+
+			Choicepoint *cp = choicestack;
+			while(cp != nil && cp->id >= goal->clausenr)
+				cp = cp->next;
+			choicestack = cp;
+			return 1;
 		}
 	}
 	return 0;
@@ -1404,3 +1403,29 @@ builtincharcode(Term *goal, Binding **bindings, Module *module)
 	}
 }
 
+int
+builtinchoicestacksize(Term *goal, Binding **bindings, Module *module)
+{
+	USED(bindings);
+	USED(module);
+	Term *size = goal->children;
+	
+	vlong i = 0;
+	Choicepoint *cp;
+	for(cp = choicestack; cp != nil; cp = cp->next)
+		i++;
+	Term *realsize = mkinteger(i);
+	return unify(size, realsize, bindings);
+}
+
+int
+builtincollectgarbage(Term *goal, Binding **bindings, Module *module)
+{
+	USED(goal);
+	USED(bindings);
+	USED(module);
+	vlong amount = collectgarbage();
+	if(amount != 0 & debug)
+		print("Collected %lld bytes of garbage\n", amount);
+	return 1;
+}
\ No newline at end of file
-- 
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