data class StringTag(val text: String)

infix fun String.tag(value: String): Pair<String, StringTag> = TODO()

fun renderTemplate(template: String, data: Map<String, StringTag> ) = TODO()

val template = """
    Happy Birthday {name} {surname}!
    from {sender}.
""".trimIndent()

val data = mapOf("name" tag "Uberto",
                 "surname" tag "Barbini",
                 "sender" tag "PragProg")

val actual = renderTemplate(template, data)

val expected = """
    Happy Birthday Uberto Barbini!
    from PragProg.
""".trimIndent()

expectThat(actual).isEqualTo(expected)