demangle.go
func (st *state) failEarlier(err string, dec int) {
	if st.off < dec {
		panic("internal error")
	}
	panic(demangleErr{err: err, off: st.off - dec})
}
func (st *state) failEarlier(err string, dec int) {
	if st.off < dec {
		panic("internal error")
	}
	panic(demangleErr{err: err, off: st.off - dec})
}
func ( st * state ) failEarlier ( err string , dec int ) { if st . off < dec { panic ( " " ) } panic ( demangleErr { err : err , off : st . off - dec } ) }
// failEarlier is like fail, but decrements the offset to indicate
// that the point of failure occurred earlier in the string.
failEarlier is like fail but decrements the offset to indicate that the point of failure occurred earlier in the string .