predicates_tree/
lib.rs

1// Copyright (c) 2018 The predicates-rs Project Developers.
2//
3// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
4// http://www.apache.org/license/LICENSE-2.0> or the MIT license
5// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
6// option. This file may not be copied, modified, or distributed
7// except according to those terms.
8
9//! Render `Case` as a tree.
10
11use std::fmt;
12
13use predicates_core::reflection;
14
15/// Render `Self` as a displayable tree.
16pub trait CaseTreeExt {
17    /// Render `Self` as a displayable tree.
18    fn tree(&self) -> CaseTree;
19}
20
21impl<'a> CaseTreeExt for reflection::Case<'a> {
22    fn tree(&self) -> CaseTree {
23        CaseTree(convert(self))
24    }
25}
26
27type CaseTreeInner = treeline::Tree<Box<dyn fmt::Display>>;
28
29fn convert(case: &reflection::Case<'_>) -> CaseTreeInner {
30    let mut leaves: Vec<CaseTreeInner> = vec![];
31
32    leaves.extend(case.predicate().iter().flat_map(|pred| {
33        pred.parameters().map(|item| {
34            let root: Box<dyn fmt::Display> = Box::new(item.to_string());
35            treeline::Tree::new(root, vec![])
36        })
37    }));
38
39    leaves.extend(case.products().map(|item| {
40        let root: Box<dyn fmt::Display> = Box::new(item.to_string());
41        treeline::Tree::new(root, vec![])
42    }));
43
44    leaves.extend(case.children().map(|item| convert(item)));
45
46    let root = Box::new(case.predicate().map(|p| p.to_string()).unwrap_or_default());
47    CaseTreeInner::new(root, leaves)
48}
49
50/// A `Case` rendered as a tree for display.
51#[allow(missing_debug_implementations)]
52pub struct CaseTree(CaseTreeInner);
53
54impl fmt::Display for CaseTree {
55    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
56        self.0.fmt(f)
57    }
58}