drawfence.go

@@ -75,6 +75,44 @@ func (c *drawCheck) checkDraws(path string, n node) error {
 	return nil
 }
 
+// checkOwnFamily refuses a table's format or cell that reads, however many templates
+// away and through a repeat or a draw group too, a table of its own family: a whole
+// read draws its row without pinning it, so the family would draw apart from the row
+// it renders, whichever draws the reaching template holds.
+// docs/decisions.md#a-table-never-reaches-its-own-family-by-any-route
+func checkOwnFamily(t *template) error {
+	own := t.table
+	if own == nil {
+		own = t.cellOf
+	}
+	if own == nil {
+		return nil
+	}
+	seen := map[node]bool{}
+	var find func(n node) (renderEdge, *table, bool)
+	find = func(n node) (renderEdge, *table, bool) {
+		if seen[n] {
+			return renderEdge{}, nil, false
+		}
+		seen[n] = true
+		for _, e := range renderEdges(n) {
+			if a, isRef := refRead(n, e.label); isRef {
+				if head, isTable := n.(*template).head(a.key).(*table); isTable && head.family() == own.family() {
+					return e, head, true
+				}
+			}
+			if e, head, found := find(e.to); found {
+				return e, head, true
+			}
+		}
+		return renderEdge{}, nil, false
+	}
+	if e, head, found := find(t); found {
+		return fmt.Errorf("%s reads %s, a table of its own family, which a bare read of %s would draw apart from the row it renders; read the family from a template beside it, or add the value as a column", e.reached(), head.category, own.category)
+	}
+	return nil
+}
+
 func renderDraws(t *template) *drawWalk {
 	w := newDrawWalk()
 	for _, e := range renderEdges(t) {
@@ -483,41 +521,3 @@ func (r *tableRead) replay(d *pinSet) error {
 	})
 	return err
 }
-
-// checkOwnFamily refuses a table's format or cell that reads, however many templates
-// away and through a repeat or a draw group too, a table of its own family: a whole
-// read draws its row without pinning it, so the family would draw apart from the row
-// it renders, whichever draws the reaching template holds.
-// docs/decisions.md#a-table-never-reaches-its-own-family-by-any-route
-func checkOwnFamily(t *template) error {
-	own := t.table
-	if own == nil {
-		own = t.cellOf
-	}
-	if own == nil {
-		return nil
-	}
-	seen := map[node]bool{}
-	var find func(n node) (renderEdge, *table, bool)
-	find = func(n node) (renderEdge, *table, bool) {
-		if seen[n] {
-			return renderEdge{}, nil, false
-		}
-		seen[n] = true
-		for _, e := range renderEdges(n) {
-			if a, isRef := refRead(n, e.label); isRef {
-				if head, isTable := n.(*template).head(a.key).(*table); isTable && head.family() == own.family() {
-					return e, head, true
-				}
-			}
-			if e, head, found := find(e.to); found {
-				return e, head, true
-			}
-		}
-		return renderEdge{}, nil, false
-	}
-	if e, head, found := find(t); found {
-		return fmt.Errorf("%s reads %s, a table of its own family, which a bare read of %s would draw apart from the row it renders; read the family from a template beside it, or add the value as a column", e.reached(), head.category, own.category)
-	}
-	return nil
-}