vam: nest_dotted

runtime/sam/expr/function/nestdotted.go

@@ -57,9 +57,13 @@ func (n *NestDotted) lookupBuilderAndType(in *super.TypeRecord) (*super.RecordBu
 
 func (n *NestDotted) Call(_ super.Allocator, args []super.Value) super.Value {
 	val := args[len(args)-1]
-	b, typ, err := n.lookupBuilderAndType(super.TypeRecordOf(val.Type()))
+	rtyp := super.TypeRecordOf(val.Type())
+	if rtyp == nil {
+		return n.zctx.WrapError("nest_dotted: non-record value", val)
+	}
+	b, typ, err := n.lookupBuilderAndType(rtyp)
 	if err != nil {
-		return n.zctx.WrapError("nest_dotted(): "+err.Error(), val)
+		return n.zctx.WrapError("nest_dotted: "+err.Error(), val)
 	}
 	if b == nil {
 		return val

runtime/vam/expr/function/function.go

@@ -57,6 +57,10 @@ func New(zctx *super.Context, name string, narg int) (expr.Function, field.Path,
 		f = &Log{zctx}
 	case "lower":
 		f = &ToLower{zctx}
+	case "nest_dotted":
+		path = field.Path{}
+		argmin = 0
+		f = &NestDotted{zctx}
 	case "network_of":
 		argmax = 2
 		f = &NetworkOf{zctx}

runtime/vam/expr/function/nestdotted.go

@@ -0,0 +1,51 @@
+package function
+
+import (
+	"github.com/brimdata/super"
+	"github.com/brimdata/super/pkg/field"
+	"github.com/brimdata/super/vector"
+)
+
+type NestDotted struct {
+	zctx *super.Context
+}
+
+func (n *NestDotted) Call(args ...vector.Any) vector.Any {
+	vec := args[len(args)-1]
+	view, ok := vec.(*vector.View)
+	if ok {
+		vec = view.Any
+	}
+	record, ok := vec.(*vector.Record)
+	if !ok {
+		return vector.NewWrappedError(n.zctx, "nest_dotted: non-record value", args[len(args)-1])
+	}
+	b, err := n.getBuilder(record.Typ)
+	if err != nil {
+		return vector.NewWrappedError(n.zctx, "nest_dotted: "+err.Error(), args[len(args)-1])
+	}
+	if b == nil {
+		return args[len(args)-1]
+	}
+	out := vector.Any(b.New(record.Fields))
+	if view != nil {
+		out = vector.NewView(out, view.Index)
+	}
+	return out
+}
+
+func (n *NestDotted) getBuilder(in *super.TypeRecord) (*vector.RecordBuilder, error) {
+	var foundDotted bool
+	var fields field.List
+	for _, f := range in.Fields {
+		dotted := field.Dotted(f.Name)
+		if len(dotted) > 1 {
+			foundDotted = true
+		}
+		fields = append(fields, dotted)
+	}
+	if !foundDotted {
+		return nil, nil
+	}
+	return vector.NewRecordBuilder(n.zctx, fields)
+}

runtime/ztests/expr/function/nest_dotted.yaml

@@ -0,0 +1,15 @@
+zed: nest_dotted(this)
+
+vector: true
+
+input: |
+  {a:1,"b.a":2,"b.b":3,"b.c.a":4,c:5}
+  {a:1,b:{a:2,b:3,c:{a:4}},c:5}
+  {a:1,"b.a":2}
+  "foo"
+
+output: |
+  {a:1,b:{a:2,b:3,c:{a:4}},c:5}
+  {a:1,b:{a:2,b:3,c:{a:4}},c:5}
+  {a:1,b:{a:2}}
+  error({message:"nest_dotted: non-record value",on:"foo"})