From: NeilBrown <neil@brown.name>
Date: Sat, 11 Dec 2021 23:42:48 +0000 (+1100)
Subject: oceani: allow field references on references.
X-Git-Url: https://ocean-lang.org/code/?p=ocean;a=commitdiff_plain;h=6e9a6bc829c370f60148deb155c3952edc6895f2

oceani: allow field references on references.

If a ref (pointer) is asked for a field, pass the request on to the
thing that is pointed to.

Signed-off-by: NeilBrown <neil@brown.name>
---

diff --git a/csrc/oceani-tests.mdc b/csrc/oceani-tests.mdc
index d672cff..655a2c9 100644
--- a/csrc/oceani-tests.mdc
+++ b/csrc/oceani-tests.mdc
@@ -730,17 +730,17 @@ A simple linked list example
 	func insert(list:@node; new:string):@node
 		p:=list
 		prev := @nil
-		while ?p and then p@.this < new:
+		while ?p and then p.this < new:
 			prev = p
-			p = p@.next
+			p = p.next
 		if ?prev:
-			prev@.next = @new()
-			prev@.next@.next = p
-			prev@.next@.this = new
+			prev.next = @new()
+			prev.next.next = p
+			prev.next.this = new
 		else
 			list = @new()
-			list@.next = p
-			list@.this = new
+			list.next = p
+			list.this = new
 		use list
 
 	func printlist(list:@node)
@@ -750,7 +750,7 @@ A simple linked list example
 
 	func freelist(list:@node)
 		if list != @nil:
-			freelist(list@.next)
+			freelist(list.next)
 			@free = list
 
 	func main(argv:[ac::]string)
@@ -1195,7 +1195,7 @@ Test for errors with references
 		ref2:@string
 		num:number = @new()
 		print num@
-		if num == @nil or ref == ref2 or ref == 2:
+		if num == @nil or ref == ref2 or ref == 2 or ref.foo:
 			@free = num
 
 ###### output: ref_err2
@@ -1206,6 +1206,8 @@ Test for errors with references
 	.tmp.code:7:33: error: expected @number but variable 'ref2' is @string
 	.tmp.code:4:8: info: this is where 'ref2' was set to @string
 	.tmp.code:7:48: error: expected @number found number
+	.tmp.code:7:53: error: field reference on number is not supported
+	.tmp.code:7:56: error: have none but need Boolean
 	.tmp.code:8:17: error: @free can only be assigned a reference, not number
 	.tmp.code:8:17: error: @free can only be assigned a reference, not number
 	oceani: type error in program - not running.
diff --git a/csrc/oceani.mdc b/csrc/oceani.mdc
index e1a2cb0..1e2bfde 100644
--- a/csrc/oceani.mdc
+++ b/csrc/oceani.mdc
@@ -3053,6 +3053,22 @@ anything in the heap or on the stack.  A reference can be assigned
 		return val->ref != NULL;
 	}
 
+	static struct type *reference_fieldref(struct type *t, struct parse_context *c,
+					       struct fieldref *f, struct value **vp)
+	{
+		struct type *rt = t->reference.referent;
+
+		if (rt->fieldref) {
+			if (vp)
+				*vp = (*vp)->ref;
+			return rt->fieldref(rt, c, f, vp);
+		}
+		type_err(c, "error: field reference on %1 is not supported",
+			         f->left, rt, 0, NULL);
+		return Tnone;
+	}
+
+
 	static struct type reference_prototype = {
 		.print_type = reference_print_type,
 		.cmp_eq = reference_cmp,
@@ -3060,6 +3076,7 @@ anything in the heap or on the stack.  A reference can be assigned
 		.test = reference_test,
 		.free = reference_free,
 		.compat = reference_compat,
+		.fieldref = reference_fieldref,
 		.size = sizeof(void*),
 		.align = sizeof(void*),
 	};