mfmt 0.4.2

Meta formatter library
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55

// https://homepages.inf.ed.ac.uk/wadler/papers/prettier/prettier.pdf
//
// Unlike the Wadler's algorithm or some other formatters like prettier, we do
// not need to search the best format given source codes. For example, we do
// not have any "group" combinator.
//
// However, we are rather given the "best" format by all information available
// in the source codes like Go.
//
// We need soft-line and if-break nodes to make nodes totally agnostic about if
// parent nodes are broken or not. But that also makes IR more complex.
// (e.g. handling trailing commas in function calls)

/// A document.
#[derive(Clone, Debug, PartialEq)]
pub enum Document<'a> {
    /// A document broken into multiple lines.
    Break {
        broken: bool,
        document: &'a Document<'a>,
    },
    /// An indented document.
    Indent(&'a Document<'a>),
    /// A line.
    ///
    /// A formatter considers it as a space if a document is not broken by
    /// [`Break`](Document::Break).
    Line,
    /// A line suffix.
    LineSuffix(&'a str),
    /// A document indented to a current column.
    ///
    /// If it is `soft`, an indent becomes equal to or more than a current
    /// indent.
    Offside {
        document: &'a Document<'a>,
        soft: bool,
    },
    /// A sequence of documents.
    Sequence(&'a [Document<'a>]),
    /// A string.
    String(&'a str),
}

impl<'a> From<&'a str> for Document<'a> {
    fn from(string: &'a str) -> Self {
        Self::String(string)
    }
}

impl<'a> From<&'a [Self]> for Document<'a> {
    fn from(documents: &'a [Self]) -> Self {
        Self::Sequence(documents)
    }
}