reproto_core/
context.rs

1//! The context of a single execution.
2//!
3//! Is used to accumulate errors.
4//!
5//! This is preferred over results, since it permits reporting complex errors and their
6//! corresponding locations.
7
8use errors::Result;
9use std::cell::{BorrowError, Ref, RefCell};
10use std::path::Path;
11use std::rc::Rc;
12use std::result;
13use {Diagnostics, Filesystem, Handle};
14
15#[derive(Debug)]
16pub enum ContextItem {
17    /// An emitted diagnostics.
18    Diagnostics { diagnostics: Diagnostics },
19}
20
21#[derive(Clone)]
22/// Context for a single reproto run.
23pub struct Context {
24    /// Filesystem abstraction.
25    filesystem: Rc<Box<Filesystem>>,
26    /// Collected context items.
27    items: Rc<RefCell<Vec<ContextItem>>>,
28}
29
30impl Context {
31    /// Create a new context with the given filesystem.
32    pub fn new(filesystem: Box<Filesystem>) -> Context {
33        Context {
34            filesystem: Rc::new(filesystem),
35            items: Rc::new(RefCell::new(vec![])),
36        }
37    }
38
39    /// Modify the existing context with a reference to the given errors.
40    pub fn with_items(self, items: Rc<RefCell<Vec<ContextItem>>>) -> Context {
41        Context { items, ..self }
42    }
43
44    /// Map the existing filesystem and return a new context with the new filesystem.
45    pub fn map_filesystem<F>(self, map: F) -> Self
46    where
47        F: FnOnce(Rc<Box<Filesystem>>) -> Box<Filesystem>,
48    {
49        Context {
50            filesystem: Rc::new(map(self.filesystem)),
51            ..self
52        }
53    }
54
55    /// Retrieve the filesystem abstraction.
56    pub fn filesystem(&self, root: Option<&Path>) -> Result<Box<Handle>> {
57        self.filesystem.open_root(root)
58    }
59
60    /// Add the given diagnostics to this context.
61    pub fn diagnostics(&self, diagnostics: Diagnostics) -> Result<()> {
62        self.items
63            .try_borrow_mut()
64            .map_err(|_| "no mutable access to context")?
65            .push(ContextItem::Diagnostics { diagnostics });
66
67        Ok(())
68    }
69
70    /// Iterate over all reporter items.
71    pub fn items(&self) -> result::Result<Ref<Vec<ContextItem>>, BorrowError> {
72        self.items.try_borrow()
73    }
74
75    /// Check if reporter is empty.
76    pub fn has_diagnostics(&self) -> Result<bool> {
77        Ok(self.items
78            .try_borrow()
79            .map_err(|_| "immutable access to context")?
80            .iter()
81            .any(|item| match *item {
82                ContextItem::Diagnostics { ref diagnostics } => diagnostics.has_errors(),
83            }))
84    }
85
86    /// Clear the context of any items.
87    pub fn clear(&self) -> Result<()> {
88        self.items
89            .try_borrow_mut()
90            .map_err(|_| "no mutable access to context")?
91            .clear();
92
93        Ok(())
94    }
95}
96
97#[cfg(test)]
98mod tests {
99    use super::*;
100    use {CapturingFilesystem, Diagnostics, Source, Span};
101
102    #[test]
103    fn test_handle() {
104        let ctx = Context::new(Box::new(CapturingFilesystem::new()));
105
106        let mut diag = Diagnostics::new(Source::empty("test"));
107        diag.err(Span::empty(), "nope");
108        diag.err(Span::empty(), "previously reported here");
109        ctx.diagnostics(diag).expect("bad diagnostic");
110
111        assert_eq!(1, ctx.items().unwrap().len());
112    }
113}
reproto_core/context.rs

reproto_core/
context.rs
