Function text_expr 

pub fn text_expr(value: &str) -> String

The Rust expression for a text attribute: "@mymod.key" is translation key mymod.key, looked up when the tree is built (::yog_api::tr, so it follows the game’s language); "@@..." is a literal text starting with @; anything else is the literal text.

"@<Set>.<name>" naming a text of resources/<Set>.yres (see set_resource_refs) is that text’s translation key.