use crate::Editor;use serde::Deserialize; #[derive(Clone, PartialEq, Deserialize)]pub enum ScrollAmount {    // Scroll N lines (positive is towards the end of the document)    Line(f32),    // Scroll N pages (positive is towards the end of the document)    Page(f32),} impl ScrollAmount {    pub fn lines(&self, editor: &mut Editor) -> f32 {        match self {            Self::Line(count) => *count,            Self::Page(count) => editor                .visible_line_count()                // subtract one to leave an anchor line                // round towards zero (so page-up and page-down are symmetric)                .map(|l| (l * count).trunc() - count.signum())                .unwrap_or(0.),        }    }}