internal/core/adt: closedness improvements

Differentiate between the one-level closedness
of the closed builtin and that of definitions.

Keep track of whether nodes use ellipses or top
values.

Issue #2884

Signed-off-by: Marcel van Lohuizen <mpvl@gmail.com>
Change-Id: I561f813b8384af7eccdfbe2d22900037b13d1229

internal/core/adt/debug.go

@@ -622,6 +622,8 @@ func (m *mermaidContext) pstr(cc *closeContext) string {
 	addFlag(cc.isDef, '#')
 	addFlag(cc.isEmbed, 'E')
 	addFlag(cc.isClosed, 'c')
+	addFlag(cc.isClosedOnce, 'C')
+	addFlag(cc.hasEllipsis, 'o')
 	io.Copy(w, flags)
 
 	w.WriteString(close)

internal/core/adt/fields.go

@@ -180,6 +180,19 @@ type closeContext struct {
 	// definition.
 	isDef bool
 
+	// hasEllipsis indicates whether the node contains an ellipsis.
+	hasEllipsis bool
+
+	// hasTop indicates a node has at least one top conjunct.
+	hasTop bool
+
+	// hasNonTop indicates a node has at least one conjunct that is not top.
+	hasNonTop bool
+
+	// isClosedOnce is true if this closeContext is the result of calling the
+	// close builtin.
+	isClosedOnce bool
+
 	// isEmbed indicates whether the closeContext is created as part of an
 	// embedding.
 	isEmbed bool
@@ -415,6 +428,13 @@ func (c *closeContext) addDependency(kind depKind, key, child *closeContext) {
 			panic("addArc: Label already exists")
 		}
 	}
+
+	// TODO: this tests seems sensible, but panics. Investigate what could
+	// trigger this.
+	// if child.src.Parent != c.src {
+	// 	panic("addArc: inconsistent parent")
+	// }
+
 	c.arcs = append(c.arcs, ccArc{kind: kind, key: key, cc: child})
 }
 
@@ -460,13 +480,20 @@ func (c *closeContext) decDependent(ctx *OpContext, kind depKind, dependant *clo
 
 	p := c.parent
 
-	if c.isDef {
+	if c.isDef && !c.hasEllipsis && (!c.hasTop || c.hasNonTop) {
 		c.isClosed = true
 		if p != nil {
 			p.isDef = true
 		}
 	}
 
+	if c.isClosedOnce {
+		c.isClosed = true
+		if p != nil {
+			p.isClosedOnce = true
+		}
+	}
+
 	for _, a := range c.arcs {
 		cc := a.cc
 		cc.decDependent(ctx, a.kind, c) // REF(arcs)
@@ -486,6 +513,16 @@ func (c *closeContext) decDependent(ctx *OpContext, kind depKind, dependant *clo
 		return
 	}
 
+	if c.hasEllipsis {
+		p.hasEllipsis = true
+	}
+	if c.hasTop {
+		p.hasTop = true
+	}
+	if c.hasNonTop {
+		p.hasNonTop = true
+	}
+
 	if !c.isEmbed && c.isClosed {
 		// Merge the two closeContexts and ensure that the patterns and fields
 		// are mutually compatible according to the closedness rules.