     # an elevated attention to the field. Oterwise, it is a simple
     # textual field that can optionally be tagged with a left icon.
     starred: (identity, synopsis, icon) ->
+        assert _.isString(identity), "invalid field identity"
+        assert _.isString(synopsis), "invalid field synopsis"
         assert _.isObject input = $ "<input>", type: "text"
         assert _.isObject label = $ "<label>", class: "label"
         assert _.isObject input.attr name: identity.toString()

    # a good idea to use such a field for inputting sorts data that
    # is not strictly required, but is usually optional, as example.
    regular: (identity, synopsis, icon) ->
        assert _.isObject input = $ "<input>", type: "text"
        assert _.isObject label = $ "<label>", class: "label"
        assert _.isObject input.attr name: identity.toString()
        field = $("<div>", class: "field").appendTo @element
        wrap = $ "<div>", class: "icon input ui left labeled"
        input.on "input", -> do -> field.removeClass "error"
        assert icon = $ "<i>", class: "icon #{icon}" if icon
        assert input.attr placeholder: synopsis.toString()
        try $(field).data "identity", identity.toString()
        field.addClass try identity.toString() if identity

        input.on "input", -> do -> field.removeClass "error"
        assert corner = $ "<div>", class: "ui corner label"
        assert asterisk = $ "<i>", class: "icon asterisk"
        sic = try _.isString(icon) and not _.isEmpty(icon)
        assert icon = $ "<i>", class: "icon #{icon}" if sic
        assert input.attr placeholder: synopsis.toString()
        try $(field).data "identity", identity.toString()
        field.addClass try identity.toString() if identity
