> actual code being embedded inside strings

My view on this is that it shouldn’t be interpreted as code being embedded inside strings, but as a special form of string concatenation syntax. In turn, this would mean that you can nest the syntax, for example:

    "foo { toUpper("bar { x + y } bar") } foo"

The individual tokens being (one per line):

    "foo {
    toUpper
    (
    "bar {
    x
    +
    y
    } bar"
    )
    } foo"

If `+` does string concatenation, the above would effectively be equivalent to:

    "foo " + toUpper("bar " + (x + y) + " bar") + " foo"

I don’t know if there is a language that actually works that way.