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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/// A struct that makes it easier to print out a pretty tree of data, which
/// can be visually scanned more easily.
pub struct PrintTree {
/// The current level of recursion.
level: u32,
/// An item which is queued up, so that we can determine if we need
/// a mid-tree prefix or a branch ending prefix.
queued_item: Option<String>,
}
impl PrintTree {
pub fn new(title: String) -> PrintTree {
println!("┌ {}", title);
PrintTree {
level: 1,
queued_item: None,
}
}
/// Descend one level in the tree with the given title.
pub fn new_level(&mut self, title: String) {
self.flush_queued_item("├─");
self.print_level_prefix();
println!("├─ {}", title);
self.level = self.level + 1;
}
/// Ascend one level in the tree.
pub fn end_level(&mut self) {
self.flush_queued_item("└─");
self.level = self.level - 1;
}
/// Add an item to the current level in the tree.
pub fn add_item(&mut self, text: String) {
self.flush_queued_item("├─");
self.queued_item = Some(text);
}
fn print_level_prefix(&self) {
for _ in 0..self.level {
print!("│ ");
}
}
fn flush_queued_item(&mut self, prefix: &str) {
if let Some(queued_item) = self.queued_item.take() {
self.print_level_prefix();
println!("{} {}", prefix, queued_item);
}
}
}
impl Drop for PrintTree {
fn drop(&mut self) {
self.flush_queued_item("└─");
}
}
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