One compiled <donedata> element - the interned counterpart to Statifier.Document.Donedata, built by the compiler's executable-content pass, reachable only through its owning :final state as elem(machine.states, i).donedata.

expr is the folded <content> value: {:compiled, ...} when the <content> child wrote an expr attribute, {:static, text} when it carried a text body instead, and nil when <donedata> has no <content> child at all. Validator check 9 (Statifier.Validator.Checks.Content) already guarantees a <content> node never carries both forms at once, so the fold cannot lose information.

expr_location is the diagnostic span for expr: the <content> node's attribute_locations[:expr] value span for the compiled arm, or the <content> node's own location for the static arm - Content.text has no span of its own by design (lib/statifier/document/content.ex:17-21). nil exactly when expr is nil.

expr carries no c_index: it is not executable content, never appears in a block, and no execute_block ever runs it.

params is the compiled, document-ordered list of <param> children - [] when <donedata> has none. expr (the <content> arm) and params are mutually exclusive by validator check (Statifier.Validator.Checks.Donedata, spec 5.5: "either a single <content> element or one or more <param> elements ... but not both"), so a %Donedata{} with both non-empty never reaches the interpreter fold. Like expr, no entry in params carries a c_index: <donedata> is not executable content.