DSL is a general name to any embedded language inside a host language. C++'s templates can be used to write DSLs, they are compile-time checked. Kotlin's lambda syntax can also create very convincing DSLs[1] to describe hierarchical structures\processes, and they are fully typed, compile-time checked constructs.

There are far more to DSLs than hacky strings (regex) or chaining method calls at runtime (fluent APIs). It's a very general pattern.

[1] Example from https://kotlinlang.org/docs/type-safe-builders.html

html {

        head {

            title {+"XML encoding with Kotlin"}

        }

        body {

            h1 {+"XML encoding with Kotlin"}

            p  {+"this format can be used as an alternative markup to XML"}

        }

}