rust/crates/ide-completion/src/item.rs

728 lines
25 KiB
Rust

//! See `CompletionItem` structure.
use std::{fmt, mem};
use hir::Mutability;
use ide_db::{
documentation::Documentation, imports::import_assets::LocatedImport, RootDatabase, SnippetCap,
SymbolKind,
};
use itertools::Itertools;
use smallvec::SmallVec;
use stdx::{impl_from, never};
use syntax::{format_smolstr, SmolStr, TextRange, TextSize};
use text_edit::TextEdit;
use crate::{
context::{CompletionContext, PathCompletionCtx},
render::{render_path_resolution, RenderContext},
};
/// `CompletionItem` describes a single completion entity which expands to 1 or more entries in the
/// editor pop-up. It is basically a POD with various properties. To construct a
/// [`CompletionItem`], use [`Builder::new`] method and the [`Builder`] struct.
#[derive(Clone)]
#[non_exhaustive]
pub struct CompletionItem {
/// Label in the completion pop up which identifies completion.
pub label: SmolStr,
/// Additional label details in the completion pop up that are
/// displayed and aligned on the right side after the label.
pub label_detail: Option<SmolStr>,
/// Range of identifier that is being completed.
///
/// It should be used primarily for UI, but we also use this to convert
/// generic TextEdit into LSP's completion edit (see conv.rs).
///
/// `source_range` must contain the completion offset. `text_edit` should
/// start with what `source_range` points to, or VSCode will filter out the
/// completion silently.
pub source_range: TextRange,
/// What happens when user selects this item.
///
/// Typically, replaces `source_range` with new identifier.
pub text_edit: TextEdit,
pub is_snippet: bool,
/// What item (struct, function, etc) are we completing.
pub kind: CompletionItemKind,
/// Lookup is used to check if completion item indeed can complete current
/// ident.
///
/// That is, in `foo.bar$0` lookup of `abracadabra` will be accepted (it
/// contains `bar` sub sequence), and `quux` will rejected.
pub lookup: SmolStr,
/// Additional info to show in the UI pop up.
pub detail: Option<String>,
pub documentation: Option<Documentation>,
/// Whether this item is marked as deprecated
pub deprecated: bool,
/// If completing a function call, ask the editor to show parameter popup
/// after completion.
pub trigger_call_info: bool,
/// We use this to sort completion. Relevance records facts like "do the
/// types align precisely?". We can't sort by relevances directly, they are
/// only partially ordered.
///
/// Note that Relevance ignores fuzzy match score. We compute Relevance for
/// all possible items, and then separately build an ordered completion list
/// based on relevance and fuzzy matching with the already typed identifier.
pub relevance: CompletionRelevance,
/// Indicates that a reference or mutable reference to this variable is a
/// possible match.
// FIXME: We shouldn't expose Mutability here (that is HIR types at all), its fine for now though
// until we have more splitting completions in which case we should think about
// generalizing this. See https://github.com/rust-lang/rust-analyzer/issues/12571
pub ref_match: Option<(Mutability, TextSize)>,
/// The import data to add to completion's edits.
/// (ImportPath, LastSegment)
pub import_to_add: SmallVec<[(String, String); 1]>,
}
// We use custom debug for CompletionItem to make snapshot tests more readable.
impl fmt::Debug for CompletionItem {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut s = f.debug_struct("CompletionItem");
s.field("label", &self.label).field("source_range", &self.source_range);
if self.text_edit.len() == 1 {
let atom = self.text_edit.iter().next().unwrap();
s.field("delete", &atom.delete);
s.field("insert", &atom.insert);
} else {
s.field("text_edit", &self.text_edit);
}
s.field("kind", &self.kind);
if self.lookup() != self.label {
s.field("lookup", &self.lookup());
}
if let Some(detail) = &self.detail {
s.field("detail", &detail);
}
if let Some(documentation) = &self.documentation {
s.field("documentation", &documentation);
}
if self.deprecated {
s.field("deprecated", &true);
}
if self.relevance != CompletionRelevance::default() {
s.field("relevance", &self.relevance);
}
if let Some((mutability, offset)) = &self.ref_match {
s.field("ref_match", &format!("&{}@{offset:?}", mutability.as_keyword_for_ref()));
}
if self.trigger_call_info {
s.field("trigger_call_info", &true);
}
s.finish()
}
}
#[derive(Debug, Clone, Copy, Eq, PartialEq, Default)]
pub struct CompletionRelevance {
/// This is set in cases like these:
///
/// ```
/// fn f(spam: String) {}
/// fn main {
/// let spam = 92;
/// f($0) // name of local matches the name of param
/// }
/// ```
pub exact_name_match: bool,
/// See CompletionRelevanceTypeMatch doc comments for cases where this is set.
pub type_match: Option<CompletionRelevanceTypeMatch>,
/// This is set in cases like these:
///
/// ```
/// fn foo(a: u32) {
/// let b = 0;
/// $0 // `a` and `b` are local
/// }
/// ```
pub is_local: bool,
/// This is set when trait items are completed in an impl of that trait.
pub is_item_from_trait: bool,
/// This is set for when trait items are from traits with `#[doc(notable_trait)]`
pub is_item_from_notable_trait: bool,
/// This is set when an import is suggested whose name is already imported.
pub is_name_already_imported: bool,
/// This is set for completions that will insert a `use` item.
pub requires_import: bool,
/// Set for method completions of the `core::ops` and `core::cmp` family.
pub is_op_method: bool,
/// Set for item completions that are private but in the workspace.
pub is_private_editable: bool,
/// Set for postfix snippet item completions
pub postfix_match: Option<CompletionRelevancePostfixMatch>,
/// This is set for type inference results
pub is_definite: bool,
/// This is set for items that are function (associated or method)
pub function: Option<CompletionRelevanceFn>,
}
#[derive(Debug, Clone, Copy, Eq, PartialEq)]
pub enum CompletionRelevanceTypeMatch {
/// This is set in cases like these:
///
/// ```
/// enum Option<T> { Some(T), None }
/// fn f(a: Option<u32>) {}
/// fn main {
/// f(Option::N$0) // type `Option<T>` could unify with `Option<u32>`
/// }
/// ```
CouldUnify,
/// This is set in cases like these:
///
/// ```
/// fn f(spam: String) {}
/// fn main {
/// let foo = String::new();
/// f($0) // type of local matches the type of param
/// }
/// ```
Exact,
}
#[derive(Debug, Clone, Copy, Eq, PartialEq)]
pub enum CompletionRelevancePostfixMatch {
/// Set in cases when item is postfix, but not exact
NonExact,
/// This is set in cases like these:
///
/// ```
/// (a > b).not$0
/// ```
///
/// Basically, we want to guarantee that postfix snippets always takes
/// precedence over everything else.
Exact,
}
#[derive(Debug, Clone, Copy, Eq, PartialEq)]
pub struct CompletionRelevanceFn {
pub has_params: bool,
pub has_self_param: bool,
pub return_type: CompletionRelevanceReturnType,
}
#[derive(Debug, Clone, Copy, Eq, PartialEq)]
pub enum CompletionRelevanceReturnType {
Other,
/// Returns the Self type of the impl/trait
DirectConstructor,
/// Returns something that indirectly constructs the `Self` type of the impl/trait e.g. `Result<Self, ()>`, `Option<Self>`
Constructor,
/// Returns a possible builder for the type
Builder,
}
impl CompletionRelevance {
/// Provides a relevance score. Higher values are more relevant.
///
/// The absolute value of the relevance score is not meaningful, for
/// example a value of 0 doesn't mean "not relevant", rather
/// it means "least relevant". The score value should only be used
/// for relative ordering.
///
/// See is_relevant if you need to make some judgement about score
/// in an absolute sense.
pub fn score(self) -> u32 {
let mut score = 0;
let CompletionRelevance {
exact_name_match,
type_match,
is_local,
is_item_from_trait,
is_name_already_imported,
requires_import,
is_op_method,
is_private_editable,
postfix_match,
is_definite,
is_item_from_notable_trait,
function,
} = self;
// lower rank private things
if !is_private_editable {
score += 1;
}
// lower rank trait op methods
if !is_op_method {
score += 10;
}
// lower rank for conflicting import names
if !is_name_already_imported {
score += 1;
}
// lower rank for items that don't need an import
if !requires_import {
score += 1;
}
if exact_name_match {
score += 10;
}
score += match postfix_match {
Some(CompletionRelevancePostfixMatch::Exact) => 100,
Some(CompletionRelevancePostfixMatch::NonExact) => 0,
None => 3,
};
score += match type_match {
Some(CompletionRelevanceTypeMatch::Exact) => 8,
Some(CompletionRelevanceTypeMatch::CouldUnify) => 3,
None => 0,
};
// slightly prefer locals
if is_local {
score += 1;
}
if is_item_from_trait {
score += 1;
}
if is_item_from_notable_trait {
score += 1;
}
if is_definite {
score += 10;
}
score += function
.map(|asf| {
let mut fn_score = match asf.return_type {
CompletionRelevanceReturnType::DirectConstructor => 15,
CompletionRelevanceReturnType::Builder => 10,
CompletionRelevanceReturnType::Constructor => 5,
CompletionRelevanceReturnType::Other => 0,
};
// When a fn is bumped due to return type:
// Bump Constructor or Builder methods with no arguments,
// over them than with self arguments
if fn_score > 0 {
if !asf.has_params {
// bump associated functions
fn_score += 1;
} else if asf.has_self_param {
// downgrade methods (below Constructor)
fn_score = 1;
}
}
fn_score
})
.unwrap_or_default();
score
}
/// Returns true when the score for this threshold is above
/// some threshold such that we think it is especially likely
/// to be relevant.
pub fn is_relevant(&self) -> bool {
self.score() > 0
}
}
/// The type of the completion item.
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
pub enum CompletionItemKind {
SymbolKind(SymbolKind),
Binding,
BuiltinType,
InferredType,
Keyword,
Snippet,
UnresolvedReference,
Expression,
}
impl_from!(SymbolKind for CompletionItemKind);
impl CompletionItemKind {
#[cfg(test)]
pub(crate) fn tag(self) -> &'static str {
match self {
CompletionItemKind::SymbolKind(kind) => match kind {
SymbolKind::Attribute => "at",
SymbolKind::BuiltinAttr => "ba",
SymbolKind::Const => "ct",
SymbolKind::ConstParam => "cp",
SymbolKind::Derive => "de",
SymbolKind::DeriveHelper => "dh",
SymbolKind::Enum => "en",
SymbolKind::Field => "fd",
SymbolKind::Function => "fn",
SymbolKind::Impl => "im",
SymbolKind::Label => "lb",
SymbolKind::LifetimeParam => "lt",
SymbolKind::Local => "lc",
SymbolKind::Macro => "ma",
SymbolKind::Method => "me",
SymbolKind::ProcMacro => "pm",
SymbolKind::Module => "md",
SymbolKind::SelfParam => "sp",
SymbolKind::SelfType => "sy",
SymbolKind::Static => "sc",
SymbolKind::Struct => "st",
SymbolKind::ToolModule => "tm",
SymbolKind::Trait => "tt",
SymbolKind::TraitAlias => "tr",
SymbolKind::TypeAlias => "ta",
SymbolKind::TypeParam => "tp",
SymbolKind::Union => "un",
SymbolKind::ValueParam => "vp",
SymbolKind::Variant => "ev",
},
CompletionItemKind::Binding => "bn",
CompletionItemKind::BuiltinType => "bt",
CompletionItemKind::InferredType => "it",
CompletionItemKind::Keyword => "kw",
CompletionItemKind::Snippet => "sn",
CompletionItemKind::UnresolvedReference => "??",
CompletionItemKind::Expression => "ex",
}
}
}
impl CompletionItem {
pub(crate) fn new(
kind: impl Into<CompletionItemKind>,
source_range: TextRange,
label: impl Into<SmolStr>,
) -> Builder {
let label = label.into();
Builder {
source_range,
label,
insert_text: None,
is_snippet: false,
trait_name: None,
detail: None,
documentation: None,
lookup: None,
kind: kind.into(),
text_edit: None,
deprecated: false,
trigger_call_info: false,
relevance: CompletionRelevance::default(),
ref_match: None,
imports_to_add: Default::default(),
doc_aliases: vec![],
}
}
/// What string is used for filtering.
pub fn lookup(&self) -> &str {
self.lookup.as_str()
}
pub fn ref_match(&self) -> Option<(String, text_edit::Indel, CompletionRelevance)> {
// Relevance of the ref match should be the same as the original
// match, but with exact type match set because self.ref_match
// is only set if there is an exact type match.
let mut relevance = self.relevance;
relevance.type_match = Some(CompletionRelevanceTypeMatch::Exact);
self.ref_match.map(|(mutability, offset)| {
(
format!("&{}{}", mutability.as_keyword_for_ref(), self.label),
text_edit::Indel::insert(offset, format!("&{}", mutability.as_keyword_for_ref())),
relevance,
)
})
}
}
/// A helper to make `CompletionItem`s.
#[must_use]
#[derive(Clone)]
pub(crate) struct Builder {
source_range: TextRange,
imports_to_add: SmallVec<[LocatedImport; 1]>,
trait_name: Option<SmolStr>,
doc_aliases: Vec<SmolStr>,
label: SmolStr,
insert_text: Option<String>,
is_snippet: bool,
detail: Option<String>,
documentation: Option<Documentation>,
lookup: Option<SmolStr>,
kind: CompletionItemKind,
text_edit: Option<TextEdit>,
deprecated: bool,
trigger_call_info: bool,
relevance: CompletionRelevance,
ref_match: Option<(Mutability, TextSize)>,
}
impl Builder {
pub(crate) fn from_resolution(
ctx: &CompletionContext<'_>,
path_ctx: &PathCompletionCtx,
local_name: hir::Name,
resolution: hir::ScopeDef,
) -> Self {
let doc_aliases = ctx.doc_aliases_in_scope(resolution);
render_path_resolution(
RenderContext::new(ctx).doc_aliases(doc_aliases),
path_ctx,
local_name,
resolution,
)
}
pub(crate) fn build(self, db: &RootDatabase) -> CompletionItem {
let _p = tracing::span!(tracing::Level::INFO, "item::Builder::build").entered();
let label = self.label;
let mut label_detail = None;
let mut lookup = self.lookup.unwrap_or_else(|| label.clone());
let insert_text = self.insert_text.unwrap_or_else(|| label.to_string());
if !self.doc_aliases.is_empty() {
let doc_aliases = self.doc_aliases.iter().join(", ");
label_detail.replace(format_smolstr!(" (alias {doc_aliases})"));
let lookup_doc_aliases = self
.doc_aliases
.iter()
// Don't include aliases in `lookup` that aren't valid identifiers as including
// them results in weird completion filtering behavior e.g. `Partial>` matching
// `PartialOrd` because it has an alias of ">".
.filter(|alias| {
let mut chars = alias.chars();
chars.next().is_some_and(char::is_alphabetic)
&& chars.all(|c| c.is_alphanumeric() || c == '_')
})
// Deliberately concatenated without separators as adding separators e.g.
// `alias1, alias2` results in LSP clients continuing to display the completion even
// after typing a comma or space.
.join("");
if !lookup_doc_aliases.is_empty() {
lookup = format_smolstr!("{lookup}{lookup_doc_aliases}");
}
}
if let [import_edit] = &*self.imports_to_add {
// snippets can have multiple imports, but normal completions only have up to one
label_detail.replace(format_smolstr!(
"{} (use {})",
label_detail.as_deref().unwrap_or_default(),
import_edit.import_path.display(db)
));
} else if let Some(trait_name) = self.trait_name {
label_detail.replace(format_smolstr!(
"{} (as {trait_name})",
label_detail.as_deref().unwrap_or_default(),
));
}
let text_edit = match self.text_edit {
Some(it) => it,
None => TextEdit::replace(self.source_range, insert_text),
};
let import_to_add = self
.imports_to_add
.into_iter()
.filter_map(|import| {
Some((
import.import_path.display(db).to_string(),
import.import_path.segments().last()?.display(db).to_string(),
))
})
.collect();
CompletionItem {
source_range: self.source_range,
label,
label_detail,
text_edit,
is_snippet: self.is_snippet,
detail: self.detail,
documentation: self.documentation,
lookup,
kind: self.kind,
deprecated: self.deprecated,
trigger_call_info: self.trigger_call_info,
relevance: self.relevance,
ref_match: self.ref_match,
import_to_add,
}
}
pub(crate) fn lookup_by(&mut self, lookup: impl Into<SmolStr>) -> &mut Builder {
self.lookup = Some(lookup.into());
self
}
pub(crate) fn label(&mut self, label: impl Into<SmolStr>) -> &mut Builder {
self.label = label.into();
self
}
pub(crate) fn trait_name(&mut self, trait_name: SmolStr) -> &mut Builder {
self.trait_name = Some(trait_name);
self
}
pub(crate) fn doc_aliases(&mut self, doc_aliases: Vec<SmolStr>) -> &mut Builder {
self.doc_aliases = doc_aliases;
self
}
pub(crate) fn insert_text(&mut self, insert_text: impl Into<String>) -> &mut Builder {
self.insert_text = Some(insert_text.into());
self
}
pub(crate) fn insert_snippet(
&mut self,
cap: SnippetCap,
snippet: impl Into<String>,
) -> &mut Builder {
let _ = cap;
self.is_snippet = true;
self.insert_text(snippet)
}
pub(crate) fn text_edit(&mut self, edit: TextEdit) -> &mut Builder {
self.text_edit = Some(edit);
self
}
pub(crate) fn snippet_edit(&mut self, _cap: SnippetCap, edit: TextEdit) -> &mut Builder {
self.is_snippet = true;
self.text_edit(edit)
}
pub(crate) fn detail(&mut self, detail: impl Into<String>) -> &mut Builder {
self.set_detail(Some(detail))
}
pub(crate) fn set_detail(&mut self, detail: Option<impl Into<String>>) -> &mut Builder {
self.detail = detail.map(Into::into);
if let Some(detail) = &self.detail {
if never!(detail.contains('\n'), "multiline detail:\n{}", detail) {
self.detail = Some(detail.split('\n').next().unwrap().to_owned());
}
}
self
}
#[allow(unused)]
pub(crate) fn documentation(&mut self, docs: Documentation) -> &mut Builder {
self.set_documentation(Some(docs))
}
pub(crate) fn set_documentation(&mut self, docs: Option<Documentation>) -> &mut Builder {
self.documentation = docs.map(Into::into);
self
}
pub(crate) fn set_deprecated(&mut self, deprecated: bool) -> &mut Builder {
self.deprecated = deprecated;
self
}
pub(crate) fn set_relevance(&mut self, relevance: CompletionRelevance) -> &mut Builder {
self.relevance = relevance;
self
}
pub(crate) fn with_relevance(
&mut self,
relevance: impl FnOnce(CompletionRelevance) -> CompletionRelevance,
) -> &mut Builder {
self.relevance = relevance(mem::take(&mut self.relevance));
self
}
pub(crate) fn trigger_call_info(&mut self) -> &mut Builder {
self.trigger_call_info = true;
self
}
pub(crate) fn add_import(&mut self, import_to_add: LocatedImport) -> &mut Builder {
self.imports_to_add.push(import_to_add);
self
}
pub(crate) fn ref_match(&mut self, mutability: Mutability, offset: TextSize) -> &mut Builder {
self.ref_match = Some((mutability, offset));
self
}
}
#[cfg(test)]
mod tests {
use itertools::Itertools;
use test_utils::assert_eq_text;
use super::{
CompletionRelevance, CompletionRelevancePostfixMatch, CompletionRelevanceTypeMatch,
};
/// Check that these are CompletionRelevance are sorted in ascending order
/// by their relevance score.
///
/// We want to avoid making assertions about the absolute score of any
/// item, but we do want to assert whether each is >, <, or == to the
/// others.
///
/// If provided vec![vec![a], vec![b, c], vec![d]], then this will assert:
/// a.score < b.score == c.score < d.score
fn check_relevance_score_ordered(expected_relevance_order: Vec<Vec<CompletionRelevance>>) {
let expected = format!("{:#?}", &expected_relevance_order);
let actual_relevance_order = expected_relevance_order
.into_iter()
.flatten()
.map(|r| (r.score(), r))
.sorted_by_key(|(score, _r)| *score)
.fold(
(u32::MIN, vec![vec![]]),
|(mut currently_collecting_score, mut out), (score, r)| {
if currently_collecting_score == score {
out.last_mut().unwrap().push(r);
} else {
currently_collecting_score = score;
out.push(vec![r]);
}
(currently_collecting_score, out)
},
)
.1;
let actual = format!("{:#?}", &actual_relevance_order);
assert_eq_text!(&expected, &actual);
}
#[test]
fn relevance_score() {
use CompletionRelevance as Cr;
let default = Cr::default();
// This test asserts that the relevance score for these items is ascending, and
// that any items in the same vec have the same score.
let expected_relevance_order = vec![
vec![],
vec![Cr { is_op_method: true, is_private_editable: true, ..default }],
vec![Cr { is_op_method: true, ..default }],
vec![Cr { postfix_match: Some(CompletionRelevancePostfixMatch::NonExact), ..default }],
vec![Cr { is_private_editable: true, ..default }],
vec![default],
vec![Cr { is_local: true, ..default }],
vec![Cr { type_match: Some(CompletionRelevanceTypeMatch::CouldUnify), ..default }],
vec![Cr { type_match: Some(CompletionRelevanceTypeMatch::Exact), ..default }],
vec![Cr { exact_name_match: true, ..default }],
vec![Cr { exact_name_match: true, is_local: true, ..default }],
vec![Cr {
exact_name_match: true,
type_match: Some(CompletionRelevanceTypeMatch::Exact),
..default
}],
vec![Cr {
exact_name_match: true,
type_match: Some(CompletionRelevanceTypeMatch::Exact),
is_local: true,
..default
}],
vec![Cr { postfix_match: Some(CompletionRelevancePostfixMatch::Exact), ..default }],
];
check_relevance_score_ordered(expected_relevance_order);
}
}