No semantic tokens returned for a function call

[rcjsuen]

This HCL file seems pretty straightforward to me but I don't have any semantic tokens for functions. Is this intentional?

group {
  name = lower("")
}

[{hcl-blockType [] example.tf:1,1-6} {hcl-attrName [] example.tf:2,3-7}]

package main

import (
	"context"
	"fmt"

	"github.com/hashicorp/hcl-lang/decoder"
	"github.com/hashicorp/hcl-lang/lang"
	"github.com/hashicorp/hcl-lang/schema"
	"github.com/hashicorp/hcl/v2"
	"github.com/hashicorp/hcl/v2/hclsyntax"
	"github.com/zclconf/go-cty/cty"
)

type PathReader struct {
	Files map[string]*hcl.File
}

func (pr *PathReader) PathContext(path lang.Path) (*decoder.PathContext, error) {
	schema := &schema.BodySchema{
		Blocks: map[string]*schema.BlockSchema{
			"group": {
				Labels: []*schema.LabelSchema{
					{
						Name: "groupName",
					},
				},
				Body: &schema.BodySchema{
					Attributes: map[string]*schema.AttributeSchema{
						"name": {
							IsOptional: true,
							Constraint: schema.AnyExpression{OfType: cty.String},
						},
					},
				},
			},
		},
	}

	return &decoder.PathContext{Schema: schema, Files: pr.Files}, nil
}

func (pr *PathReader) Paths(ctx context.Context) []lang.Path {
	return []lang.Path{}
}

func main() {
	f, pDiags := hclsyntax.ParseConfig([]byte("group {\n  name = lower(\"\")\n}"), "example.tf", hcl.InitialPos)
	if len(pDiags) > 0 {
		panic(pDiags)
	}

	decoder := decoder.NewDecoder(&PathReader{Files: map[string]*hcl.File{"example.tf": f}})
	pathDecoder, err := decoder.Path(lang.Path{Path: ".", LanguageID: "terraform"})
	if err != nil {
		panic(err)
	}

	tokens, err := pathDecoder.SemanticTokensInFile(context.Background(), "example.tf")
	if err != nil {
		panic(err)
	}
	fmt.Println(tokens)
}