rustfmt-wrapper 0.2.1

Library wrapper around rustfmt for use by code generators
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
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219

// Copyright 2022 Oxide Computer Company

use serde::Serialize;

// Process the configuration options lifted from the rustfmt repo. Note that
// the default value is ignored, but left in to simplify updates.
macro_rules! create_config {
    ($($i:ident: $ty:ty, $def:expr, $stb:expr, $( $dstring:expr ),+ );+ $(;)*) => {
        /// `rustfmt` configuration.
        ///
        /// See the [`rustfmt` documentation](https://rust-lang.github.io/rustfmt)
        /// for the descriptions of these stable and non-stable options.
        #[derive(Serialize, Default)]
        pub struct Config {
            $(
                $(
                    #[doc = $dstring]
                )*
                #[serde(skip_serializing_if = "Option::is_none")]
                pub $i: Option<$ty>,
            )*
        }

        impl Config {
            pub(crate) fn unstable(&self) -> bool {
                false
                $(
                    // Not stable and explicitly set.
                    || (!$stb && self.$i.is_some())
                )*
            }

            pub(crate) fn list_unstable(&self) -> String {
                let mut list = Vec::new();
                $(
                    if !$stb && self.$i.is_some() {
                        list.push(stringify!($i));
                    }
                )*
                list.join(", ")
            }
        }
    };
}

// Per https://github.com/rust-lang/rustfmt/blob/master/src/config/mod.rs
// ... skipping the section titled "Not user-facing" and "Control options".
//
// This macro defines configuration options used in rustfmt. Each option
// is defined as follows:
//
// `name: value type, default value, is stable, description;`
create_config! {
    // Fundamental stuff
    max_width: usize, 100, true, "Maximum width of each line";
    hard_tabs: bool, false, true, "Use tab characters for indentation, spaces for alignment";
    tab_spaces: usize, 4, true, "Number of spaces per tab";
    newline_style: NewlineStyle, NewlineStyle::Auto, true, "Unix or Windows line endings";
    indent_style: IndentStyle, IndentStyle::Block, false, "How do we indent expressions or items";

    // Width Heuristics
    use_small_heuristics: Heuristics, Heuristics::Default, true, "Whether to use different \
        formatting for items and expressions if they satisfy a heuristic notion of 'small'";
    fn_call_width: usize, 60, true, "Maximum width of the args of a function call before \
        falling back to vertical formatting.";
    attr_fn_like_width: usize, 70, true, "Maximum width of the args of a function-like \
        attributes before falling back to vertical formatting.";
    struct_lit_width: usize, 18, true, "Maximum width in the body of a struct lit before \
        falling back to vertical formatting.";
    struct_variant_width: usize, 35, true, "Maximum width in the body of a struct variant before \
        falling back to vertical formatting.";
    array_width: usize, 60, true,  "Maximum width of an array literal before falling \
        back to vertical formatting.";
    chain_width: usize, 60, true, "Maximum length of a chain to fit on a single line.";
    single_line_if_else_max_width: usize, 50, true, "Maximum line length for single line if-else \
        expressions. A value of zero means always break if-else expressions.";

    // Comments. macros, and strings
    wrap_comments: bool, false, false, "Break comments to fit on the line";
    format_code_in_doc_comments: bool, false, false, "Format the code snippet in doc comments.";
    doc_comment_code_block_width: usize, 100, false, "Maximum width for code snippets in doc \
        comments. No effect unless format_code_in_doc_comments = true";
    comment_width: usize, 80, false,
        "Maximum length of comments. No effect unless wrap_comments = true";
    normalize_comments: bool, false, false, "Convert /* */ comments to // comments where possible";
    normalize_doc_attributes: bool, false, false, "Normalize doc attributes as doc comments";
    format_strings: bool, false, false, "Format string literals where necessary";
    format_macro_matchers: bool, false, false,
        "Format the metavariable matching patterns in macros";
    format_macro_bodies: bool, true, false, "Format the bodies of macros";
    hex_literal_case: HexLiteralCase, HexLiteralCase::Preserve, false,
        "Format hexadecimal integer literals";

    // Single line expressions and items
    empty_item_single_line: bool, true, false,
        "Put empty-body functions and impls on a single line";
    struct_lit_single_line: bool, true, false,
        "Put small struct literals on a single line";
    fn_single_line: bool, false, false, "Put single-expression functions on a single line";
    where_single_line: bool, false, false, "Force where-clauses to be on a single line";

    // Imports
    imports_indent: IndentStyle, IndentStyle::Block, false, "Indent of imports";
    imports_layout: ListTactic, ListTactic::Mixed, false, "Item layout inside a import block";
    imports_granularity: ImportGranularity, ImportGranularity::Preserve, false,
        "Merge or split imports to the provided granularity";
    group_imports: GroupImportsTactic, GroupImportsTactic::Preserve, false,
        "Controls the strategy for how imports are grouped together";
    merge_imports: bool, false, false, "(deprecated: use imports_granularity instead)";

    // Ordering
    reorder_imports: bool, true, true, "Reorder import and extern crate statements alphabetically";
    reorder_modules: bool, true, true, "Reorder module statements alphabetically in group";
    reorder_impl_items: bool, false, false, "Reorder impl items";

    // Spaces around punctuation
    type_punctuation_density: TypeDensity, TypeDensity::Wide, false,
        "Determines if '+' or '=' are wrapped in spaces in the punctuation of types";
    space_before_colon: bool, false, false, "Leave a space before the colon";
    space_after_colon: bool, true, false, "Leave a space after the colon";
    spaces_around_ranges: bool, false, false, "Put spaces around the  .. and ..= range operators";
    binop_separator: SeparatorPlace, SeparatorPlace::Front, false,
        "Where to put a binary operator when a binary expression goes multiline";

    // Misc.
    remove_nested_parens: bool, true, true, "Remove nested parens";
    combine_control_expr: bool, true, false, "Combine control expressions with function calls";
    short_array_element_width_threshold: usize, 10, true,
        "Width threshold for an array element to be considered short";
    overflow_delimited_expr: bool, false, false,
        "Allow trailing bracket/brace delimited expressions to overflow";
    struct_field_align_threshold: usize, 0, false,
        "Align struct fields if their diffs fits within threshold";
    enum_discrim_align_threshold: usize, 0, false,
        "Align enum variants discrims, if their diffs fit within threshold";
    match_arm_blocks: bool, true, false, "Wrap the body of arms in blocks when it does not fit on \
        the same line with the pattern of arms";
    match_arm_leading_pipes: MatchArmLeadingPipe, MatchArmLeadingPipe::Never, true,
        "Determines whether leading pipes are emitted on match arms";
    force_multiline_blocks: bool, false, false,
        "Force multiline closure bodies and match arms to be wrapped in a block";
    fn_args_layout: Density, Density::Tall, true,
        "Control the layout of arguments in a function";
    brace_style: BraceStyle, BraceStyle::SameLineWhere, false, "Brace style for items";
    control_brace_style: ControlBraceStyle, ControlBraceStyle::AlwaysSameLine, false,
        "Brace style for control flow constructs";
    trailing_semicolon: bool, true, false,
        "Add trailing semicolon after break, continue and return";
    trailing_comma: SeparatorTactic, SeparatorTactic::Vertical, false,
        "How to handle trailing commas for lists";
    match_block_trailing_comma: bool, false, true,
        "Put a trailing comma after a block based match arm (non-block arms are not affected)";
    blank_lines_upper_bound: usize, 1, false,
        "Maximum number of blank lines which can be put between items";
    blank_lines_lower_bound: usize, 0, false,
        "Minimum number of blank lines which must be put between items";
    edition: Edition, Edition::Edition2015, true, "The edition of the parser (RFC 2052)";
    version: Version, Version::One, false, "Version of formatting rules";
    inline_attribute_width: usize, 0, false,
        "Write an item and its attribute on the same line \
        if their combined width is below a threshold";
    format_generated_files: bool, true, false, "Format generated files";

    // Options that can change the source code beyond whitespace/blocks (somewhat linty things)
    merge_derives: bool, true, true, "Merge multiple `#[derive(...)]` into a single one";
    use_try_shorthand: bool, false, true, "Replace uses of the try! macro by the ? shorthand";
    use_field_init_shorthand: bool, false, true, "Use field initialization shorthand if possible";
    force_explicit_abi: bool, true, true, "Always print the abi for extern items";
    condense_wildcard_suffixes: bool, false, false, "Replace strings of _ wildcards by a single .. \
                                                     in tuple patterns";

    // Control options (changes the operation of rustfmt, rather than the formatting)
    // [..] deleted

    // Not user-facing
    // [..] deleted
}

macro_rules! make_enum {
    ($name:ident $(, $v:ident)+) => {
        #[derive(Serialize)]
        pub enum $name {
            $( $v, )*
        }
    };
}

make_enum!(NewlineStyle, Auto, Windows, Unix, Native);
make_enum!(IndentStyle, Visual, Block);
make_enum!(Heuristics, Off, Max, Default);
make_enum!(HexLiteralCase, Preserve, Upper, Lower);
make_enum!(ListTactic, Vertical, Horizontal, HorizontalVertical, Mixed);
make_enum!(ImportGranularity, Preserve, Crate, Module, Item, One);
make_enum!(GroupImportsTactic, Preserve, StdExternalCrate, One);
make_enum!(TypeDensity, Compressed, Wide);
make_enum!(SeparatorPlace, Front, Back);
make_enum!(MatchArmLeadingPipe, Always, Never, Preserve);
make_enum!(Density, Compressed, Tall, Vertical);
make_enum!(BraceStyle, AlwaysNextLine, PreferSameLine, SameLineWhere);
make_enum!(
    ControlBraceStyle,
    AlwaysSameLine,
    ClosingNextLine,
    AlwaysNextLine
);
make_enum!(SeparatorTactic, Always, Never, Vertical);
make_enum!(Version, One, Two);

#[derive(Serialize)]
pub enum Edition {
    #[serde(rename = "2015")]
    Edition2015,
    #[serde(rename = "2018")]
    Edition2018,
    #[serde(rename = "2021")]
    Edition2021,
    #[serde(rename = "2024")]
    Edition2024,
}