5976: Complete trait impl immediately after type/const/fn r=jonas-schievink a=oxalica

Currently, we can complete type/const/fn but only if we typed an identifier.
That is, `impl .. { fn f<|> }` has completions with all trait fn including `f`, but `impl .. { fn <|> }` doesn't provide any suggestion (even if explicit trigger it).

This PR tweak the logic of completion match to make it possible.

However, we still need to explicit trigger suggestions (`Control + Space` by default) in vscode to show. Not sure if we can make it automatically triggered after typing the space after `fn`.

Another question is that I cannot figure out why `BLOCK_EXPR` need to be checked. A block expr directly inside a impl block should be invalid, and nested items will failed to locate impl block in specific offset and skip the suggestion. Now I simply removed it and no tests are broken.
4f91478e50/crates/ide/src/completion/complete_trait_impl.rs (L109)


Co-authored-by: oxalica <oxalicc@pm.me>
This commit is contained in:
bors[bot] 2020-09-14 10:22:20 +00:00 committed by GitHub
commit d134a81037
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@ -46,76 +46,76 @@ use crate::{
display::function_declaration,
};
#[derive(Debug, PartialEq, Eq)]
enum ImplCompletionKind {
All,
Fn,
TypeAlias,
Const,
}
pub(crate) fn complete_trait_impl(acc: &mut Completions, ctx: &CompletionContext) {
if let Some((trigger, impl_def)) = completion_match(ctx) {
match trigger.kind() {
SyntaxKind::NAME_REF => get_missing_assoc_items(&ctx.sema, &impl_def)
.into_iter()
.for_each(|item| match item {
hir::AssocItem::Function(fn_item) => {
add_function_impl(&trigger, acc, ctx, fn_item)
}
hir::AssocItem::TypeAlias(type_item) => {
add_type_alias_impl(&trigger, acc, ctx, type_item)
}
hir::AssocItem::Const(const_item) => {
add_const_impl(&trigger, acc, ctx, const_item)
}
}),
SyntaxKind::FN => {
for missing_fn in get_missing_assoc_items(&ctx.sema, &impl_def)
.into_iter()
.filter_map(|item| match item {
hir::AssocItem::Function(fn_item) => Some(fn_item),
_ => None,
})
{
add_function_impl(&trigger, acc, ctx, missing_fn);
}
if let Some((kind, trigger, impl_def)) = completion_match(ctx) {
get_missing_assoc_items(&ctx.sema, &impl_def).into_iter().for_each(|item| match item {
hir::AssocItem::Function(fn_item)
if kind == ImplCompletionKind::All || kind == ImplCompletionKind::Fn =>
{
add_function_impl(&trigger, acc, ctx, fn_item)
}
SyntaxKind::TYPE_ALIAS => {
for missing_fn in get_missing_assoc_items(&ctx.sema, &impl_def)
.into_iter()
.filter_map(|item| match item {
hir::AssocItem::TypeAlias(type_item) => Some(type_item),
_ => None,
})
{
add_type_alias_impl(&trigger, acc, ctx, missing_fn);
}
hir::AssocItem::TypeAlias(type_item)
if kind == ImplCompletionKind::All || kind == ImplCompletionKind::TypeAlias =>
{
add_type_alias_impl(&trigger, acc, ctx, type_item)
}
SyntaxKind::CONST => {
for missing_fn in get_missing_assoc_items(&ctx.sema, &impl_def)
.into_iter()
.filter_map(|item| match item {
hir::AssocItem::Const(const_item) => Some(const_item),
_ => None,
})
{
add_const_impl(&trigger, acc, ctx, missing_fn);
}
hir::AssocItem::Const(const_item)
if kind == ImplCompletionKind::All || kind == ImplCompletionKind::Const =>
{
add_const_impl(&trigger, acc, ctx, const_item)
}
_ => {}
}
});
}
}
fn completion_match(ctx: &CompletionContext) -> Option<(SyntaxNode, Impl)> {
let (trigger, impl_def_offset) = ctx.token.ancestors().find_map(|p| match p.kind() {
SyntaxKind::FN | SyntaxKind::TYPE_ALIAS | SyntaxKind::CONST | SyntaxKind::BLOCK_EXPR => {
Some((p, 2))
fn completion_match(ctx: &CompletionContext) -> Option<(ImplCompletionKind, SyntaxNode, Impl)> {
let mut token = ctx.token.clone();
// For keywork without name like `impl .. { fn <|> }`, the current position is inside
// the whitespace token, which is outside `FN` syntax node.
// We need to follow the previous token in this case.
if token.kind() == SyntaxKind::WHITESPACE {
token = token.prev_token()?;
}
let (kind, trigger, impl_def_offset) = token.ancestors().find_map(|p| match p.kind() {
// `const` can be a modifier of an item, so the `const` token may be inside another item syntax node.
// Eg. `impl .. { const <|> fn bar() .. }`
SyntaxKind::FN | SyntaxKind::TYPE_ALIAS | SyntaxKind::CONST
if token.kind() == SyntaxKind::CONST_KW =>
{
Some((ImplCompletionKind::Const, p, 2))
}
SyntaxKind::NAME_REF => Some((p, 5)),
SyntaxKind::FN => Some((ImplCompletionKind::Fn, p, 2)),
SyntaxKind::TYPE_ALIAS => Some((ImplCompletionKind::TypeAlias, p, 2)),
SyntaxKind::CONST => Some((ImplCompletionKind::Const, p, 2)),
// `impl .. { const <|> }` is parsed as:
// IMPL
// ASSOC_ITEM_LIST
// ERROR
// CONST_KW <- token
// WHITESPACE <- ctx.token
SyntaxKind::ERROR
if p.first_token().map_or(false, |t| t.kind() == SyntaxKind::CONST_KW) =>
{
Some((ImplCompletionKind::Const, p, 2))
}
SyntaxKind::NAME_REF => Some((ImplCompletionKind::All, p, 5)),
_ => None,
})?;
let impl_def = (0..impl_def_offset - 1)
.try_fold(trigger.parent()?, |t, _| t.parent())
.and_then(ast::Impl::cast)?;
Some((trigger, impl_def))
Some((kind, trigger, impl_def))
}
fn add_function_impl(
@ -485,4 +485,67 @@ impl Test for () {
",
);
}
#[test]
fn complete_without_name() {
let test = |completion: &str, hint: &str, completed: &str, next_sibling: &str| {
println!(
"completion='{}', hint='{}', next_sibling='{}'",
completion, hint, next_sibling
);
check_edit(
completion,
&format!(
r#"
trait Test {{
type Foo;
const CONST: u16;
fn bar();
}}
struct T;
impl Test for T {{
{}
{}
}}
"#,
hint, next_sibling
),
&format!(
r#"
trait Test {{
type Foo;
const CONST: u16;
fn bar();
}}
struct T;
impl Test for T {{
{}
{}
}}
"#,
completed, next_sibling
),
)
};
// Enumerate some possible next siblings.
for next_sibling in &[
"",
"fn other_fn() {}", // `const <|> fn` -> `const fn`
"type OtherType = i32;",
"const OTHER_CONST: i32 = 0;",
"async fn other_fn() {}",
"unsafe fn other_fn() {}",
"default fn other_fn() {}",
"default type OtherType = i32;",
"default const OTHER_CONST: i32 = 0;",
] {
test("bar", "fn <|>", "fn bar() {\n $0\n}", next_sibling);
test("Foo", "type <|>", "type Foo = ", next_sibling);
test("CONST", "const <|>", "const CONST: u16 = ", next_sibling);
}
}
}