如何在go模板调用中使用$ variable

Question

i use the go template

it work:

{{range $k, $name := .userList}}
    <tr>
        <a href="/?id={{$k}}">{{call .Tr "hey"}}</a>
    </tr>
{{end}}

it not work: get the err : at <.Tr>: can't evaluate field Tr in type string

{{range $k, $name := .userList}}
    <tr>
        <a href="/?id={{$k}}">{{call .Tr $name}}</a>
    </tr>
{{end}}

i want use $name for the Tr func , how can i do ?