aboutsummaryrefslogtreecommitdiff
path: root/crates/ra_assists/src/utils.rs
blob: 0038a9764b15da65f5a82c61404afd9f66c2b871 (plain)
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
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
//! Assorted functions shared by several assists.
pub(crate) mod insert_use;

use std::{iter, ops};

use hir::{Adt, Crate, Enum, ScopeDef, Semantics, Trait, Type};
use ra_ide_db::RootDatabase;
use ra_syntax::{
    ast::{self, make, NameOwner},
    AstNode, SyntaxNode, T,
};
use rustc_hash::FxHashSet;

use crate::assist_config::SnippetCap;

pub(crate) use insert_use::insert_use_statement;

#[derive(Clone, Copy, Debug)]
pub(crate) enum Cursor<'a> {
    Replace(&'a SyntaxNode),
    Before(&'a SyntaxNode),
}

impl<'a> Cursor<'a> {
    fn node(self) -> &'a SyntaxNode {
        match self {
            Cursor::Replace(node) | Cursor::Before(node) => node,
        }
    }
}

pub(crate) fn render_snippet(_cap: SnippetCap, node: &SyntaxNode, cursor: Cursor) -> String {
    assert!(cursor.node().ancestors().any(|it| it == *node));
    let range = cursor.node().text_range() - node.text_range().start();
    let range: ops::Range<usize> = range.into();

    let mut placeholder = cursor.node().to_string();
    escape(&mut placeholder);
    let tab_stop = match cursor {
        Cursor::Replace(placeholder) => format!("${{0:{}}}", placeholder),
        Cursor::Before(placeholder) => format!("$0{}", placeholder),
    };

    let mut buf = node.to_string();
    buf.replace_range(range, &tab_stop);
    return buf;

    fn escape(buf: &mut String) {
        stdx::replace(buf, '{', r"\{");
        stdx::replace(buf, '}', r"\}");
        stdx::replace(buf, '$', r"\$");
    }
}

pub fn get_missing_assoc_items(
    sema: &Semantics<RootDatabase>,
    impl_def: &ast::ImplDef,
) -> Vec<hir::AssocItem> {
    // Names must be unique between constants and functions. However, type aliases
    // may share the same name as a function or constant.
    let mut impl_fns_consts = FxHashSet::default();
    let mut impl_type = FxHashSet::default();

    if let Some(item_list) = impl_def.item_list() {
        for item in item_list.assoc_items() {
            match item {
                ast::AssocItem::FnDef(f) => {
                    if let Some(n) = f.name() {
                        impl_fns_consts.insert(n.syntax().to_string());
                    }
                }

                ast::AssocItem::TypeAliasDef(t) => {
                    if let Some(n) = t.name() {
                        impl_type.insert(n.syntax().to_string());
                    }
                }

                ast::AssocItem::ConstDef(c) => {
                    if let Some(n) = c.name() {
                        impl_fns_consts.insert(n.syntax().to_string());
                    }
                }
            }
        }
    }

    resolve_target_trait(sema, impl_def).map_or(vec![], |target_trait| {
        target_trait
            .items(sema.db)
            .iter()
            .filter(|i| match i {
                hir::AssocItem::Function(f) => {
                    !impl_fns_consts.contains(&f.name(sema.db).to_string())
                }
                hir::AssocItem::TypeAlias(t) => !impl_type.contains(&t.name(sema.db).to_string()),
                hir::AssocItem::Const(c) => c
                    .name(sema.db)
                    .map(|n| !impl_fns_consts.contains(&n.to_string()))
                    .unwrap_or_default(),
            })
            .cloned()
            .collect()
    })
}

pub(crate) fn resolve_target_trait(
    sema: &Semantics<RootDatabase>,
    impl_def: &ast::ImplDef,
) -> Option<hir::Trait> {
    let ast_path = impl_def
        .target_trait()
        .map(|it| it.syntax().clone())
        .and_then(ast::PathType::cast)?
        .path()?;

    match sema.resolve_path(&ast_path) {
        Some(hir::PathResolution::Def(hir::ModuleDef::Trait(def))) => Some(def),
        _ => None,
    }
}

pub(crate) fn invert_boolean_expression(expr: ast::Expr) -> ast::Expr {
    if let Some(expr) = invert_special_case(&expr) {
        return expr;
    }
    make::expr_prefix(T![!], expr)
}

fn invert_special_case(expr: &ast::Expr) -> Option<ast::Expr> {
    match expr {
        ast::Expr::BinExpr(bin) => match bin.op_kind()? {
            ast::BinOp::NegatedEqualityTest => bin.replace_op(T![==]).map(|it| it.into()),
            ast::BinOp::EqualityTest => bin.replace_op(T![!=]).map(|it| it.into()),
            _ => None,
        },
        ast::Expr::PrefixExpr(pe) if pe.op_kind()? == ast::PrefixOp::Not => pe.expr(),
        // FIXME:
        // ast::Expr::Literal(true | false )
        _ => None,
    }
}

#[derive(Clone, Copy)]
pub enum TryEnum {
    Result,
    Option,
}

impl TryEnum {
    const ALL: [TryEnum; 2] = [TryEnum::Option, TryEnum::Result];

    pub fn from_ty(sema: &Semantics<RootDatabase>, ty: &Type) -> Option<TryEnum> {
        let enum_ = match ty.as_adt() {
            Some(Adt::Enum(it)) => it,
            _ => return None,
        };
        TryEnum::ALL.iter().find_map(|&var| {
            if &enum_.name(sema.db).to_string() == var.type_name() {
                return Some(var);
            }
            None
        })
    }

    pub(crate) fn happy_case(self) -> &'static str {
        match self {
            TryEnum::Result => "Ok",
            TryEnum::Option => "Some",
        }
    }

    pub(crate) fn sad_pattern(self) -> ast::Pat {
        match self {
            TryEnum::Result => make::tuple_struct_pat(
                make::path_unqualified(make::path_segment(make::name_ref("Err"))),
                iter::once(make::placeholder_pat().into()),
            )
            .into(),
            TryEnum::Option => make::bind_pat(make::name("None")).into(),
        }
    }

    fn type_name(self) -> &'static str {
        match self {
            TryEnum::Result => "Result",
            TryEnum::Option => "Option",
        }
    }
}

/// Helps with finding well-know things inside the standard library. This is
/// somewhat similar to the known paths infra inside hir, but it different; We
/// want to make sure that IDE specific paths don't become interesting inside
/// the compiler itself as well.
pub(crate) struct FamousDefs<'a, 'b>(pub(crate) &'a Semantics<'b, RootDatabase>, pub(crate) Crate);

#[allow(non_snake_case)]
impl FamousDefs<'_, '_> {
    #[cfg(test)]
    pub(crate) const FIXTURE: &'static str = r#"
//- /libcore.rs crate:core
pub mod convert {
    pub trait From<T> {
        fn from(T) -> Self;
    }
}

pub mod option {
    pub enum Option<T> { None, Some(T)}
}

pub mod prelude {
    pub use crate::{convert::From, option::Option::{self, *}};
}
#[prelude_import]
pub use prelude::*;
"#;

    pub(crate) fn core_convert_From(&self) -> Option<Trait> {
        self.find_trait("core:convert:From")
    }

    pub(crate) fn core_option_Option(&self) -> Option<Enum> {
        self.find_enum("core:option:Option")
    }

    fn find_trait(&self, path: &str) -> Option<Trait> {
        match self.find_def(path)? {
            hir::ScopeDef::ModuleDef(hir::ModuleDef::Trait(it)) => Some(it),
            _ => None,
        }
    }

    fn find_enum(&self, path: &str) -> Option<Enum> {
        match self.find_def(path)? {
            hir::ScopeDef::ModuleDef(hir::ModuleDef::Adt(hir::Adt::Enum(it))) => Some(it),
            _ => None,
        }
    }

    fn find_def(&self, path: &str) -> Option<ScopeDef> {
        let db = self.0.db;
        let mut path = path.split(':');
        let trait_ = path.next_back()?;
        let std_crate = path.next()?;
        let std_crate = self
            .1
            .dependencies(db)
            .into_iter()
            .find(|dep| &dep.name.to_string() == std_crate)?
            .krate;

        let mut module = std_crate.root_module(db)?;
        for segment in path {
            module = module.children(db).find_map(|child| {
                let name = child.name(db)?;
                if &name.to_string() == segment {
                    Some(child)
                } else {
                    None
                }
            })?;
        }
        let def =
            module.scope(db, None).into_iter().find(|(name, _def)| &name.to_string() == trait_)?.1;
        Some(def)
    }
}