//! Completion of names from the current scope in expression position.
use hir::ScopeDef;
use crate::{
context::{ExprCtx, PathCompletionCtx, Qualified},
CompletionContext, Completions,
};
pub(crate) fn complete_expr_path(
acc: &mut Completions,
ctx: &CompletionContext<'_>,
path_ctx @ PathCompletionCtx { qualified, .. }: &PathCompletionCtx,
&ExprCtx {
in_block_expr,
in_loop_body,
after_if_expr,
in_condition,
incomplete_let,
ref ref_expr_parent,
ref is_func_update,
ref innermost_ret_ty,
ref impl_,
..
}: &ExprCtx,
) {
let _p = profile::span("complete_expr_path");
if !ctx.qualifier_ctx.none() {
return;
}
let wants_mut_token =
ref_expr_parent.as_ref().map(|it| it.mut_token().is_none()).unwrap_or(false);
let scope_def_applicable = |def| match def {
ScopeDef::GenericParam(hir::GenericParam::LifetimeParam(_)) | ScopeDef::Label(_) => false,
ScopeDef::ModuleDef(hir::ModuleDef::Macro(mac)) => mac.is_fn_like(ctx.db),
_ => true,
};
let add_assoc_item = |acc: &mut Completions, item| match item {
hir::AssocItem::Function(func) => acc.add_function(ctx, path_ctx, func, None),
hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
};
match qualified {
Qualified::Infer => ctx
.traits_in_scope()
.iter()
.flat_map(|&it| hir::Trait::from(it).items(ctx.sema.db))
.for_each(|item| add_assoc_item(acc, item)),
Qualified::With { resolution: None, .. } => {}
Qualified::With { resolution: Some(resolution), .. } => {
// Add associated types on type parameters and `Self`.
ctx.scope.assoc_type_shorthand_candidates(resolution, |_, alias| {
acc.add_type_alias(ctx, alias);
None::<()>
});
match resolution {
hir::PathResolution::Def(hir::ModuleDef::Module(module)) => {
let module_scope = module.scope(ctx.db, Some(ctx.module));
for (name, def) in module_scope {
if scope_def_applicable(def) {
acc.add_path_resolution(ctx, path_ctx, name, def);
}
}
}
hir::PathResolution::Def(
def @ (hir::ModuleDef::Adt(_)
| hir::ModuleDef::TypeAlias(_)
| hir::ModuleDef::BuiltinType(_)),
) => {
let ty = match def {
hir::ModuleDef::Adt(adt) => adt.ty(ctx.db),
hir::ModuleDef::TypeAlias(a) => a.ty(ctx.db),
hir::ModuleDef::BuiltinType(builtin) => {
cov_mark::hit!(completes_primitive_assoc_const);
builtin.ty(ctx.db)
}
_ => return,
};
if let Some(hir::Adt::Enum(e)) = ty.as_adt() {
cov_mark::hit!(completes_variant_through_alias);
acc.add_enum_variants(ctx, path_ctx, e);
}
// XXX: For parity with Rust bug #22519, this does not complete Ty::AssocType.
// (where AssocType is defined on a trait, not an inherent impl)
ctx.iterate_path_candidates(&ty, |item| {
add_assoc_item(acc, item);
});
// Iterate assoc types separately
ty.iterate_assoc_items(ctx.db, ctx.krate, |item| {
if let hir::AssocItem::TypeAlias(ty) = item {
acc.add_type_alias(ctx, ty)
}
None::<()>
});
}
hir::PathResolution::Def(hir::ModuleDef::Trait(t)) => {
// Handles `Trait::assoc` as well as `<Ty as Trait>::assoc`.
for item in t.items(ctx.db) {
add_assoc_item(acc, item);
}
}
hir::PathResolution::TypeParam(_) | hir::PathResolution::SelfType(_) => {
let ty = match resolution {
hir::PathResolution::TypeParam(param) => param.ty(ctx.db),
hir::PathResolution::SelfType(impl_def) => impl_def.self_ty(ctx.db),
_ => return,
};
if let Some(hir::Adt::Enum(e)) = ty.as_adt() {
cov_mark::hit!(completes_variant_through_self);
acc.add_enum_variants(ctx, path_ctx, e);
}
ctx.iterate_path_candidates(&ty, |item| {
add_assoc_item(acc, item);
});
}
_ => (),
}
}
Qualified::Absolute => acc.add_crate_roots(ctx, path_ctx),
Qualified::No => {
acc.add_nameref_keywords_with_colon(ctx);
if let Some(adt) =
ctx.expected_type.as_ref().and_then(|ty| ty.strip_references().as_adt())
{
let self_ty = (|| ctx.sema.to_def(impl_.as_ref()?)?.self_ty(ctx.db).as_adt())();
let complete_self = self_ty == Some(adt);
match adt {
hir::Adt::Struct(strukt) => {
let path = ctx
.module
.find_use_path(ctx.db, hir::ModuleDef::from(strukt))
.filter(|it| it.len() > 1);
acc.add_struct_literal(ctx, path_ctx, strukt, path, None);
if complete_self {
acc.add_struct_literal(
ctx,
path_ctx,
strukt,
None,
Some(hir::known::SELF_TYPE),
);
}
}
hir::Adt::Union(un) => {
let path = ctx
.module
.find_use_path(ctx.db, hir::ModuleDef::from(un))
.filter(|it| it.len() > 1);
acc.add_union_literal(ctx, un, path, None);
if complete_self {
acc.add_union_literal(ctx, un, None, Some(hir::known::SELF_TYPE));
}
}
hir::Adt::Enum(e) => {
super::enum_variants_with_paths(
acc,
ctx,
e,
impl_,
|acc, ctx, variant, path| {
acc.add_qualified_enum_variant(ctx, path_ctx, variant, path)
},
);
}
}
}
ctx.process_all_names(&mut |name, def| {
if scope_def_applicable(def) {
acc.add_path_resolution(ctx, path_ctx, name, def);
}
});
if is_func_update.is_none() {
let mut add_keyword =
|kw, snippet| acc.add_keyword_snippet_expr(ctx, incomplete_let, kw, snippet);
if !in_block_expr {
add_keyword("unsafe", "unsafe {\n $0\n}");
}
add_keyword("match", "match $1 {\n $0\n}");
add_keyword("while", "while $1 {\n $0\n}");
add_keyword("while let", "while let $1 = $2 {\n $0\n}");
add_keyword("loop", "loop {\n $0\n}");
add_keyword("if", "if $1 {\n $0\n}");
add_keyword("if let", "if let $1 = $2 {\n $0\n}");
add_keyword("for", "for $1 in $2 {\n $0\n}");
add_keyword("true", "true");
add_keyword("false", "false");
if in_condition || in_block_expr {
add_keyword("let", "let");
}
if after_if_expr {
add_keyword("else", "else {\n $0\n}");
add_keyword("else if", "else if $1 {\n $0\n}");
}
if wants_mut_token {
add_keyword("mut", "mut ");
}
if in_loop_body {
if in_block_expr {
add_keyword("continue", "continue;");
add_keyword("break", "break;");
} else {
add_keyword("continue", "continue");
add_keyword("break", "break");
}
}
if let Some(ty) = innermost_ret_ty {
add_keyword(
"return",
match (in_block_expr, ty.is_unit()) {
(true, true) => "return ;",
(true, false) => "return;",
(false, true) => "return $0",
(false, false) => "return",
},
);
}
}
}
}
}