Combining templates with `fold`/`match` -> no two closures have the same type. about horrorshow-rs HOT 3 CLOSED

fn list_directories_recursive(&self, path: &Path) -> Option<String> {
    let entries = path.read_dir().unwrap() 
        .filter_map(|de| de.ok())         // remove invalid paths
        .map(|de| de.path())              // DirectoryEntry -> Path
        .filter(|p| self.visible_path(p)) // remove invisible paths
        .map(|path| {
            let (href, name) = match (
                path.as_os_str().to_str(),
                path.file_name().and_then(|f|f.to_str())
            ) {
                (Some(href), Some(name)) => {
                    let href = href.replacen(".", "", 1); // ./thing -> /thing
                    let name = name.replacen("/", "", 1); // ./dir/thing -> thing
                    (href, name)
                }
                _ => return None,
            };
            return Some((path, href, name))
        })
        .filter_map(|s| s);

    let listings = (html! {
        @ for (path, href, name) in entries {
            @ if self.list_recursively && path.is_dir() {
                // No need to check if None. None renders as ""
                : self.list_directories_recursive(&path)
            }
            tr {
                td {
                    a(href=&href) : name
                }
            }
        }
    }).into_string().unwrap();

    if listings.len() != 0 {
        Some(listings)
    } else {
        None
    }
}

fn list_directories_recursive(&self, path: &Path) -> Option<String> {
    let listings = (html! {
        |tmpl| path.read_dir().unwrap() 
            .filter_map(|de| de.ok())         // remove invalid paths
            .map(|de| de.path())              // DirectoryEntry -> Path
            .filter(|p| self.visible_path(p)) // remove invisible paths
            .map(|path| {
                let (href, name) = match (
                    path.as_os_str().to_str(),
                    path.file_name().and_then(|f|f.to_str())
                ) {
                    (Some(href), Some(name)) => {
                        let href = href.replacen(".", "", 1); // ./thing -> /thing
                        let name = name.replacen("/", "", 1); // ./dir/thing -> thing
                        (href, name)
                    }
                    _ => return None,
                };
                return Some((path, href, name))
            })
            .filter_map(|s| s)
            .for_each(|(path, href, name)| &mut *tmpl << html! {
                @ if self.list_recursively && path.is_dir() {
                    // No need to check if None. None renders as ""
                    : self.list_directories_recursive(&path)
                }
                tr {
                    td {
                        a(href=&href) : name
                    }
                }
            })
    }).into_string().unwrap();

    if listings.len() != 0 {
        Some(listings)
    } else {
        None
    }
}

template! {
    // Where Context is the "Self" type.
    ListDirectories(ctx: &Context, path: &Path) {
        |tmpl| path.read_dir().unwrap() 
            .filter_map(|de| de.ok())         // remove invalid paths
            .map(|de| de.path())              // DirectoryEntry -> Path
            .filter(|p| ctx.visible_path(p))  // remove invisible paths
            .map(|path| {
                let (href, name) = match (
                    path.as_os_str().to_str(),
                    path.file_name().and_then(|f|f.to_str())
                ) {
                    (Some(href), Some(name)) => {
                        let href = href.replacen(".", "", 1); // ./thing -> /thing
                        let name = name.replacen("/", "", 1); // ./dir/thing -> thing
                        (href, name)
                    }
                    _ => return None,
                };
                return Some((path, href, name))
            })
            .filter_map(|s| s)
            .for_each(|(path, href, name)| &mut *tmpl << html! {
                @ if ctx.list_recursively && path.is_dir() {
                    : ListDirectories::new(ctx, &path)
                }
                tr {
                    td {
                        a(href=&href) : name
                    }
                }
            })
    }
}