Vars

d2ast/d2ast.go

@@ -502,6 +502,17 @@ type UnquotedString struct {
 	Value []InterpolationBox `json:"value"`
 }
 
+func (s *UnquotedString) Coalesce() {
+	var b strings.Builder
+	for _, box := range s.Value {
+		if box.String == nil {
+			break
+		}
+		b.WriteString(*box.String)
+	}
+	s.SetString(b.String())
+}
+
 func FlatUnquotedString(s string) *UnquotedString {
 	return &UnquotedString{
 		Value: []InterpolationBox{{String: &s}},
@@ -513,6 +524,17 @@ type DoubleQuotedString struct {
 	Value []InterpolationBox `json:"value"`
 }
 
+func (s *DoubleQuotedString) Coalesce() {
+	var b strings.Builder
+	for _, box := range s.Value {
+		if box.String == nil {
+			break
+		}
+		b.WriteString(*box.String)
+	}
+	s.SetString(b.String())
+}
+
 func FlatDoubleQuotedString(s string) *DoubleQuotedString {
 	return &DoubleQuotedString{
 		Value: []InterpolationBox{{String: &s}},

d2compiler/compile.go

@@ -277,6 +277,16 @@ func (c *compiler) compileField(obj *d2graph.Object, f *d2ir.Field) {
 			}
 		}
 		return
+	} else if f.Name == "vars" {
+		if f.Map() != nil {
+			if len(f.Map().Edges) > 0 {
+				c.errorf(f.Map().Edges[0].LastRef().AST(), "vars cannot contain an edge")
+			}
+		}
+		if d2ir.NodeBoardKind(d2ir.ParentMap(f)) == "" {
+			c.errorf(f.LastRef().AST(), "vars must be defined at the root of a board")
+		}
+		return
 	} else if isReserved {
 		c.compileReserved(&obj.Attributes, f)
 		return