Go's preferred way would probably be something like compute the aliased operations on the line(s) before, then reference the final values.
E.G. Adapting https://github.com/golang/go/issues/34174
f := 123.45
fmt.Fprintln("value=%08.3f{f}") // value=0123.450
fmt.Fprintln("value=%08.3f", f) // value=0123.450
s := "value"
fmt.Fprintln("value='%50s{s}'") // value='<45 spaces>value'
fmt.Fprintln("value='%50s'", s) // value='<45 spaces>value'
The inline {variable} reference suffix format would be less confusing for situations that involve _many_ variables. Though I'm a bit more partial to this syntax with an immediately trailing %{variable} packet since my gut feeling is that special case would be cleaner in a parser. fmt.Fprintln("value=%08.3f%{f}") // value=0123.450
fmt.Fprintln("value='%50s%{s}'") // value='<45 spaces>value'
