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
|
//! FIXME: write short doc here
use hir::db::HirDatabase;
use ra_syntax::{
ast::{self, edit, make, AstNode, NameOwner, TypeBoundsOwner},
SyntaxElement,
SyntaxKind::*,
};
use crate::{Assist, AssistCtx, AssistId};
pub(crate) fn move_bounds_to_where_clause(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
let type_param_list = ctx.node_at_offset::<ast::TypeParamList>()?;
let mut type_params = type_param_list.type_params();
if type_params.all(|p| p.type_bound_list().is_none()) {
return None;
}
let parent = type_param_list.syntax().parent()?;
if parent.children_with_tokens().find(|it| it.kind() == WHERE_CLAUSE).is_some() {
return None;
}
let anchor: SyntaxElement = match parent.kind() {
FN_DEF => ast::FnDef::cast(parent)?.body()?.syntax().clone().into(),
TRAIT_DEF => ast::TraitDef::cast(parent)?.item_list()?.syntax().clone().into(),
IMPL_BLOCK => ast::ImplBlock::cast(parent)?.item_list()?.syntax().clone().into(),
ENUM_DEF => ast::EnumDef::cast(parent)?.variant_list()?.syntax().clone().into(),
STRUCT_DEF => parent
.children_with_tokens()
.find(|it| it.kind() == RECORD_FIELD_DEF_LIST || it.kind() == SEMI)?,
_ => return None,
};
ctx.add_action(
AssistId("move_bounds_to_where_clause"),
"move_bounds_to_where_clause",
|edit| {
let new_params = type_param_list
.type_params()
.filter(|it| it.type_bound_list().is_some())
.map(|type_param| {
let without_bounds = type_param.remove_bounds();
(type_param, without_bounds)
});
let new_type_param_list = edit::replace_descendants(&type_param_list, new_params);
edit.replace_ast(type_param_list.clone(), new_type_param_list);
let where_clause = {
let predicates = type_param_list.type_params().filter_map(build_predicate);
make::where_clause(predicates)
};
let to_insert = match anchor.prev_sibling_or_token() {
Some(ref elem) if elem.kind() == WHITESPACE => {
format!("{} ", where_clause.syntax())
}
_ => format!(" {}", where_clause.syntax()),
};
edit.insert(anchor.text_range().start(), to_insert);
edit.target(type_param_list.syntax().text_range());
},
);
ctx.build()
}
fn build_predicate(param: ast::TypeParam) -> Option<ast::WherePred> {
let path = make::path_from_name_ref(make::name_ref(¶m.name()?.syntax().to_string()));
let predicate = make::where_pred(path, param.type_bound_list()?.bounds());
Some(predicate)
}
#[cfg(test)]
mod tests {
use super::*;
use crate::helpers::check_assist;
#[test]
fn move_bounds_to_where_clause_fn() {
check_assist(
move_bounds_to_where_clause,
r#"
fn foo<T: u32, <|>F: FnOnce(T) -> T>() {}
"#,
r#"
fn foo<T, <|>F>() where T: u32, F: FnOnce(T) -> T {}
"#,
);
}
#[test]
fn move_bounds_to_where_clause_impl() {
check_assist(
move_bounds_to_where_clause,
r#"
impl<U: u32, <|>T> A<U, T> {}
"#,
r#"
impl<U, <|>T> A<U, T> where U: u32 {}
"#,
);
}
#[test]
fn move_bounds_to_where_clause_struct() {
check_assist(
move_bounds_to_where_clause,
r#"
struct A<<|>T: Iterator<Item = u32>> {}
"#,
r#"
struct A<<|>T> where T: Iterator<Item = u32> {}
"#,
);
}
#[test]
fn move_bounds_to_where_clause_tuple_struct() {
check_assist(
move_bounds_to_where_clause,
r#"
struct Pair<<|>T: u32>(T, T);
"#,
r#"
struct Pair<<|>T>(T, T) where T: u32;
"#,
);
}
}
|
