-use hir::{

- known, Adjust, AutoBorrow, Callable, HasVisibility, HirDisplay, Mutability, OverloadedDeref,

- PointerCast, Safety, Semantics, TypeInfo,

-};

-use ide_db::{

- base_db::FileRange, famous_defs::FamousDefs, syntax_helpers::node_ext::walk_ty, FxHashMap,

- RootDatabase,

-};

-use stdx::to_lower_snake_case;

- ast::{self, AstNode, HasArgList, HasGenericParams, HasName, UnaryOp},

- match_ast, Direction, NodeOrToken, SmolStr, SyntaxKind, SyntaxNode, SyntaxToken, TextRange,

- TextSize, T,

- closing_brace_hints(hints, sema, config, file_id, node.clone());

- chaining_hints(hints, sema, &famous_defs, config, file_id, &expr);

- adjustment_hints(hints, sema, config, &expr);

- ast::Expr::CallExpr(it) => param_name_hints(hints, sema, config, ast::Expr::from(it)),

- param_name_hints(hints, sema, config, ast::Expr::from(it))

- ast::Expr::ClosureExpr(it) => closure_ret_hints(hints, sema, &famous_defs, config, file_id, it),

- binding_mode_hints(hints, sema, config, &it);

- bind_pat_hints(hints, sema, config, file_id, &it);

- ast::Item::Fn(it) => fn_lifetime_fn_hints(hints, config, it),

- ast::Item::Static(it) => implicit_static_hints(hints, config, Either::Left(it)),

- ast::Item::Const(it) => implicit_static_hints(hints, config, Either::Right(it)),

-fn closing_brace_hints(

- acc: &mut Vec<InlayHint>,

- sema: &Semantics<'_, RootDatabase>,

- config: &InlayHintsConfig,

- file_id: FileId,

- node: SyntaxNode,

-) -> Option<()> {

- let min_lines = config.closing_brace_hints_min_lines?;

-

- let name = |it: ast::Name| it.syntax().text_range();

-

- let mut closing_token;

- let (label, name_range) = if let Some(item_list) = ast::AssocItemList::cast(node.clone()) {

- closing_token = item_list.r_curly_token()?;

-

- let parent = item_list.syntax().parent()?;

- match_ast! {

- match parent {

- ast::Impl(imp) => {

- let imp = sema.to_def(&imp)?;

- let ty = imp.self_ty(sema.db);

- let trait_ = imp.trait_(sema.db);

- let hint_text = match trait_ {

- Some(tr) => format!("impl {} for {}", tr.name(sema.db), ty.display_truncated(sema.db, config.max_length)),

- None => format!("impl {}", ty.display_truncated(sema.db, config.max_length)),

- };

- (hint_text, None)

- },

- ast::Trait(tr) => {

- (format!("trait {}", tr.name()?), tr.name().map(name))

- },

- _ => return None,

- }

- }

- } else if let Some(list) = ast::ItemList::cast(node.clone()) {

- closing_token = list.r_curly_token()?;

-

- let module = ast::Module::cast(list.syntax().parent()?)?;

- (format!("mod {}", module.name()?), module.name().map(name))

- } else if let Some(block) = ast::BlockExpr::cast(node.clone()) {

- closing_token = block.stmt_list()?.r_curly_token()?;

-

- let parent = block.syntax().parent()?;

- match_ast! {

- match parent {

- ast::Fn(it) => {

- // FIXME: this could include parameters, but `HirDisplay` prints too much info

- // and doesn't respect the max length either, so the hints end up way too long

- (format!("fn {}", it.name()?), it.name().map(name))

- },

- ast::Static(it) => (format!("static {}", it.name()?), it.name().map(name)),

- ast::Const(it) => {

- if it.underscore_token().is_some() {

- ("const _".into(), None)

- } else {

- (format!("const {}", it.name()?), it.name().map(name))

- }

- },

- _ => return None,

- }

- }

- } else if let Some(mac) = ast::MacroCall::cast(node.clone()) {

- let last_token = mac.syntax().last_token()?;

- if last_token.kind() != T![;] && last_token.kind() != SyntaxKind::R_CURLY {

- return None;

- }

- closing_token = last_token;

-

- (

- format!("{}!", mac.path()?),

- mac.path().and_then(|it| it.segment()).map(|it| it.syntax().text_range()),

- )

- } else {

- return None;

- };

-

- if let Some(mut next) = closing_token.next_token() {

- if next.kind() == T![;] {

- if let Some(tok) = next.next_token() {

- closing_token = next;

- next = tok;

- }

- }

- if !(next.kind() == SyntaxKind::WHITESPACE && next.text().contains('\n')) {

- // Only display the hint if the `}` is the last token on the line

- return None;

- }

- }

-

- let mut lines = 1;

- node.text().for_each_chunk(|s| lines += s.matches('\n').count());

- if lines < min_lines {

- return None;

- }

-

- let linked_location = name_range.map(|range| FileRange { file_id, range });

- acc.push(InlayHint {

- range: closing_token.text_range(),

- kind: InlayKind::ClosingBraceHint,

- label: InlayHintLabel { parts: vec![InlayHintLabelPart { text: label, linked_location }] },

- tooltip: None, // provided by label part location

- });

-

- None

-}

-

-fn implicit_static_hints(

- acc: &mut Vec<InlayHint>,

- config: &InlayHintsConfig,

- statik_or_const: Either<ast::Static, ast::Const>,

-) -> Option<()> {

- if config.lifetime_elision_hints != LifetimeElisionHints::Always {

- return None;

- }

-

- if let Either::Right(it) = &statik_or_const {

- if ast::AssocItemList::can_cast(

- it.syntax().parent().map_or(SyntaxKind::EOF, |it| it.kind()),

- ) {

- return None;

- }

- }

-

- if let Some(ast::Type::RefType(ty)) = statik_or_const.either(|it| it.ty(), |it| it.ty()) {

- if ty.lifetime().is_none() {

- let t = ty.amp_token()?;

- acc.push(InlayHint {

- range: t.text_range(),

- kind: InlayKind::LifetimeHint,

- label: "'static".to_owned().into(),

- tooltip: Some(InlayTooltip::String("Elided static lifetime".into())),

- });

- }

- }

-

- Some(())

-}

-

-fn fn_lifetime_fn_hints(

- acc: &mut Vec<InlayHint>,

- config: &InlayHintsConfig,

- func: ast::Fn,

-) -> Option<()> {

- if config.lifetime_elision_hints == LifetimeElisionHints::Never {

- return None;

- }

-

- let mk_lt_hint = |t: SyntaxToken, label: String| InlayHint {

- range: t.text_range(),

- kind: InlayKind::LifetimeHint,

- label: label.into(),

- tooltip: Some(InlayTooltip::String("Elided lifetime".into())),

- };

-

- let param_list = func.param_list()?;

- let generic_param_list = func.generic_param_list();

- let ret_type = func.ret_type();

- let self_param = param_list.self_param().filter(|it| it.amp_token().is_some());

-

- let is_elided = |lt: &Option<ast::Lifetime>| match lt {

- Some(lt) => matches!(lt.text().as_str(), "'_"),

- None => true,

- };

-

- let potential_lt_refs = {

- let mut acc: Vec<_> = vec![];

- if let Some(self_param) = &self_param {

- let lifetime = self_param.lifetime();

- let is_elided = is_elided(&lifetime);

- acc.push((None, self_param.amp_token(), lifetime, is_elided));

- }

- param_list.params().filter_map(|it| Some((it.pat(), it.ty()?))).for_each(|(pat, ty)| {

- // FIXME: check path types

- walk_ty(&ty, &mut |ty| match ty {

- ast::Type::RefType(r) => {

- let lifetime = r.lifetime();

- let is_elided = is_elided(&lifetime);

- acc.push((

- pat.as_ref().and_then(|it| match it {

- ast::Pat::IdentPat(p) => p.name(),

- _ => None,

- }),

- r.amp_token(),

- lifetime,

- is_elided,

- ))

- }

- _ => (),

- })

- });

- acc

- };

-

- // allocate names

- let mut gen_idx_name = {

- let mut gen = (0u8..).map(|idx| match idx {

- idx if idx < 10 => SmolStr::from_iter(['\'', (idx + 48) as char]),

- idx => format!("'{idx}").into(),

- });

- move || gen.next().unwrap_or_default()

- };

- let mut allocated_lifetimes = vec![];

-

- let mut used_names: FxHashMap<SmolStr, usize> =

- match config.param_names_for_lifetime_elision_hints {

- true => generic_param_list

- .iter()

- .flat_map(|gpl| gpl.lifetime_params())

- .filter_map(|param| param.lifetime())

- .filter_map(|lt| Some((SmolStr::from(lt.text().as_str().get(1..)?), 0)))

- .collect(),

- false => Default::default(),

- };

- {

- let mut potential_lt_refs = potential_lt_refs.iter().filter(|&&(.., is_elided)| is_elided);

- if let Some(_) = &self_param {

- if let Some(_) = potential_lt_refs.next() {

- allocated_lifetimes.push(if config.param_names_for_lifetime_elision_hints {

- // self can't be used as a lifetime, so no need to check for collisions

- "'self".into()

- } else {

- gen_idx_name()

- });

- }

- }

- potential_lt_refs.for_each(|(name, ..)| {

- let name = match name {

- Some(it) if config.param_names_for_lifetime_elision_hints => {

- if let Some(c) = used_names.get_mut(it.text().as_str()) {

- *c += 1;

- SmolStr::from(format!("'{text}{c}", text = it.text().as_str()))

- } else {

- used_names.insert(it.text().as_str().into(), 0);

- SmolStr::from_iter(["\'", it.text().as_str()])

- }

- }

- _ => gen_idx_name(),

- };

- allocated_lifetimes.push(name);

- });

- }

-

- // fetch output lifetime if elision rule applies

- let output = match potential_lt_refs.as_slice() {

- [(_, _, lifetime, _), ..] if self_param.is_some() || potential_lt_refs.len() == 1 => {

- match lifetime {

- Some(lt) => match lt.text().as_str() {

- "'_" => allocated_lifetimes.get(0).cloned(),

- "'static" => None,

- name => Some(name.into()),

- },

- None => allocated_lifetimes.get(0).cloned(),

- }

- }

- [..] => None,

- };

-

- if allocated_lifetimes.is_empty() && output.is_none() {

- return None;

- }

-

- // apply hints

- // apply output if required

- let mut is_trivial = true;

- if let (Some(output_lt), Some(r)) = (&output, ret_type) {

- if let Some(ty) = r.ty() {

- walk_ty(&ty, &mut |ty| match ty {

- ast::Type::RefType(ty) if ty.lifetime().is_none() => {

- if let Some(amp) = ty.amp_token() {

- is_trivial = false;

- acc.push(mk_lt_hint(amp, output_lt.to_string()));

- }

- }

- _ => (),

- })

- }

- }

-

- if config.lifetime_elision_hints == LifetimeElisionHints::SkipTrivial && is_trivial {

- return None;

- }

-

- let mut a = allocated_lifetimes.iter();

- for (_, amp_token, _, is_elided) in potential_lt_refs {

- if is_elided {

- let t = amp_token?;

- let lt = a.next()?;

- acc.push(mk_lt_hint(t, lt.to_string()));

- }

- }

-

- // generate generic param list things

- match (generic_param_list, allocated_lifetimes.as_slice()) {

- (_, []) => (),

- (Some(gpl), allocated_lifetimes) => {

- let angle_tok = gpl.l_angle_token()?;

- let is_empty = gpl.generic_params().next().is_none();

- acc.push(InlayHint {

- range: angle_tok.text_range(),

- kind: InlayKind::LifetimeHint,

- label: format!(

- "{}{}",

- allocated_lifetimes.iter().format(", "),

- if is_empty { "" } else { ", " }

- )

- .into(),

- tooltip: Some(InlayTooltip::String("Elided lifetimes".into())),

- });

- }

- (None, allocated_lifetimes) => acc.push(InlayHint {

- range: func.name()?.syntax().text_range(),

- kind: InlayKind::GenericParamListHint,

- label: format!("<{}>", allocated_lifetimes.iter().format(", "),).into(),

- tooltip: Some(InlayTooltip::String("Elided lifetimes".into())),

- }),

- }

- Some(())

-}

-

-fn closure_ret_hints(

- acc: &mut Vec<InlayHint>,

- sema: &Semantics<'_, RootDatabase>,

- famous_defs: &FamousDefs<'_, '_>,

- config: &InlayHintsConfig,

- file_id: FileId,

- closure: ast::ClosureExpr,

-) -> Option<()> {

- if config.closure_return_type_hints == ClosureReturnTypeHints::Never {

- return None;

- }

-

- if closure.ret_type().is_some() {

- return None;

- }

-

- if !closure_has_block_body(&closure)

- && config.closure_return_type_hints == ClosureReturnTypeHints::WithBlock

- {

- return None;

- }

-

- let param_list = closure.param_list()?;

-

- let closure = sema.descend_node_into_attributes(closure.clone()).pop()?;

- let ty = sema.type_of_expr(&ast::Expr::ClosureExpr(closure))?.adjusted();

- let callable = ty.as_callable(sema.db)?;

- let ty = callable.return_type();

- if ty.is_unit() {

- return None;

- }

- acc.push(InlayHint {

- range: param_list.syntax().text_range(),

- kind: InlayKind::ClosureReturnTypeHint,

- label: hint_iterator(sema, &famous_defs, config, &ty)

- .unwrap_or_else(|| ty.display_truncated(sema.db, config.max_length).to_string())

- .into(),

- tooltip: Some(InlayTooltip::HoverRanged(file_id, param_list.syntax().text_range())),

- });

- Some(())

-}

-

-fn adjustment_hints(

- acc: &mut Vec<InlayHint>,

- sema: &Semantics<'_, RootDatabase>,

- config: &InlayHintsConfig,

- expr: &ast::Expr,

-) -> Option<()> {

- if config.adjustment_hints == AdjustmentHints::Never {

- return None;

- }

-

- // These inherit from the inner expression which would result in duplicate hints

- if let ast::Expr::ParenExpr(_)

- | ast::Expr::IfExpr(_)

- | ast::Expr::BlockExpr(_)

- | ast::Expr::MatchExpr(_) = expr

- {

- return None;

- }

-

- let parent = expr.syntax().parent().and_then(ast::Expr::cast);

- let descended = sema.descend_node_into_attributes(expr.clone()).pop();

- let desc_expr = descended.as_ref().unwrap_or(expr);

- let adjustments = sema.expr_adjustments(desc_expr).filter(|it| !it.is_empty())?;

- let needs_parens = match parent {

- Some(parent) => {

- match parent {

- ast::Expr::AwaitExpr(_)

- | ast::Expr::CallExpr(_)

- | ast::Expr::CastExpr(_)

- | ast::Expr::FieldExpr(_)

- | ast::Expr::MethodCallExpr(_)

- | ast::Expr::TryExpr(_) => true,

- // FIXME: shorthands need special casing, though not sure if adjustments are even valid there

- ast::Expr::RecordExpr(_) => false,

- ast::Expr::IndexExpr(index) => index.base().as_ref() == Some(expr),

- _ => false,

- }

- }

- None => false,

- };

- if needs_parens {

- acc.push(InlayHint {

- range: expr.syntax().text_range(),

- kind: InlayKind::OpeningParenthesis,

- label: "(".into(),

- tooltip: None,

- });

- }

- for adjustment in adjustments.into_iter().rev() {

- // FIXME: Add some nicer tooltips to each of these

- let text = match adjustment {

- Adjust::NeverToAny if config.adjustment_hints == AdjustmentHints::Always => {

- "<never-to-any>"

- }

- Adjust::Deref(None) => "*",

- Adjust::Deref(Some(OverloadedDeref(Mutability::Mut))) => "*",

- Adjust::Deref(Some(OverloadedDeref(Mutability::Shared))) => "*",

- Adjust::Borrow(AutoBorrow::Ref(Mutability::Shared)) => "&",

- Adjust::Borrow(AutoBorrow::Ref(Mutability::Mut)) => "&mut ",

- Adjust::Borrow(AutoBorrow::RawPtr(Mutability::Shared)) => "&raw const ",

- Adjust::Borrow(AutoBorrow::RawPtr(Mutability::Mut)) => "&raw mut ",

- // some of these could be represented via `as` casts, but that's not too nice and

- // handling everything as a prefix expr makes the `(` and `)` insertion easier

- Adjust::Pointer(cast) if config.adjustment_hints == AdjustmentHints::Always => {

- match cast {

- PointerCast::ReifyFnPointer => "<fn-item-to-fn-pointer>",

- PointerCast::UnsafeFnPointer => "<safe-fn-pointer-to-unsafe-fn-pointer>",

- PointerCast::ClosureFnPointer(Safety::Unsafe) => {

- "<closure-to-unsafe-fn-pointer>"

- }

- PointerCast::ClosureFnPointer(Safety::Safe) => "<closure-to-fn-pointer>",

- PointerCast::MutToConstPointer => "<mut-ptr-to-const-ptr>",

- PointerCast::ArrayToPointer => "<array-ptr-to-element-ptr>",

- PointerCast::Unsize => "<unsize>",

- }

- }

- _ => continue,

- };

- acc.push(InlayHint {

- range: expr.syntax().text_range(),

- kind: InlayKind::AdjustmentHint,

- label: text.into(),

- tooltip: None,

- });

- }

- if needs_parens {

- acc.push(InlayHint {

- range: expr.syntax().text_range(),

- kind: InlayKind::ClosingParenthesis,

- label: ")".into(),

- tooltip: None,

- });

- }

- Some(())

-}

-

-fn chaining_hints(

- acc: &mut Vec<InlayHint>,

- sema: &Semantics<'_, RootDatabase>,

- famous_defs: &FamousDefs<'_, '_>,

- config: &InlayHintsConfig,

- file_id: FileId,

- expr: &ast::Expr,

-) -> Option<()> {

- if !config.chaining_hints {

- return None;

- }

-

- if matches!(expr, ast::Expr::RecordExpr(_)) {

- return None;

- }

-

- let descended = sema.descend_node_into_attributes(expr.clone()).pop();

- let desc_expr = descended.as_ref().unwrap_or(expr);

-

- let mut tokens = expr

- .syntax()

- .siblings_with_tokens(Direction::Next)

- .filter_map(NodeOrToken::into_token)

- .filter(|t| match t.kind() {

- SyntaxKind::WHITESPACE if !t.text().contains('\n') => false,

- SyntaxKind::COMMENT => false,

- _ => true,

- });

-

- // Chaining can be defined as an expression whose next sibling tokens are newline and dot

- // Ignoring extra whitespace and comments

- let next = tokens.next()?.kind();

- if next == SyntaxKind::WHITESPACE {

- let mut next_next = tokens.next()?.kind();

- while next_next == SyntaxKind::WHITESPACE {

- next_next = tokens.next()?.kind();

- }

- if next_next == T![.] {

- let ty = sema.type_of_expr(desc_expr)?.original;

- if ty.is_unknown() {

- return None;

- }

- if matches!(expr, ast::Expr::PathExpr(_)) {

- if let Some(hir::Adt::Struct(st)) = ty.as_adt() {

- if st.fields(sema.db).is_empty() {

- return None;

- }

- }

- }

- acc.push(InlayHint {

- range: expr.syntax().text_range(),

- kind: InlayKind::ChainingHint,

- label: hint_iterator(sema, &famous_defs, config, &ty)

- .unwrap_or_else(|| ty.display_truncated(sema.db, config.max_length).to_string())

- .into(),

- tooltip: Some(InlayTooltip::HoverRanged(file_id, expr.syntax().text_range())),

- });

- }

- }

- Some(())

-}

-

-fn param_name_hints(

- acc: &mut Vec<InlayHint>,

- sema: &Semantics<'_, RootDatabase>,

- config: &InlayHintsConfig,

- expr: ast::Expr,

-) -> Option<()> {

- if !config.parameter_hints {

- return None;

- }

-

- let (callable, arg_list) = get_callable(sema, &expr)?;

- let hints = callable

- .params(sema.db)

- .into_iter()

- .zip(arg_list.args())

- .filter_map(|((param, _ty), arg)| {

- // Only annotate hints for expressions that exist in the original file

- let range = sema.original_range_opt(arg.syntax())?;

- let (param_name, name_syntax) = match param.as_ref()? {

- Either::Left(pat) => ("self".to_string(), pat.name()),

- Either::Right(pat) => match pat {

- ast::Pat::IdentPat(it) => (it.name()?.to_string(), it.name()),

- _ => return None,

- },

- };

- Some((name_syntax, param_name, arg, range))

- })

- .filter(|(_, param_name, arg, _)| {

- !should_hide_param_name_hint(sema, &callable, param_name, arg)

- })

- .map(|(param, param_name, _, FileRange { range, .. })| {

- let mut tooltip = None;

- if let Some(name) = param {

- if let hir::CallableKind::Function(f) = callable.kind() {

- // assert the file is cached so we can map out of macros

- if let Some(_) = sema.source(f) {

- tooltip = sema.original_range_opt(name.syntax());

- }

- }

- }

-

- InlayHint {

- range,

- kind: InlayKind::ParameterHint,

- label: param_name.into(),

- tooltip: tooltip.map(|it| InlayTooltip::HoverOffset(it.file_id, it.range.start())),

- }

- });

-

- acc.extend(hints);

- Some(())

-}

-

-fn binding_mode_hints(

- acc: &mut Vec<InlayHint>,

- sema: &Semantics<'_, RootDatabase>,

- config: &InlayHintsConfig,

- pat: &ast::Pat,

-) -> Option<()> {

- if !config.binding_mode_hints {

- return None;

- }

-

- let outer_paren_pat = pat

- .syntax()

- .ancestors()

- .skip(1)

- .map_while(ast::Pat::cast)

- .map_while(|pat| match pat {

- ast::Pat::ParenPat(pat) => Some(pat),

- _ => None,

- })

- .last();

- let range =

- outer_paren_pat.as_ref().map_or_else(|| pat.syntax(), |it| it.syntax()).text_range();

- sema.pattern_adjustments(&pat).iter().for_each(|ty| {

- let reference = ty.is_reference();

- let mut_reference = ty.is_mutable_reference();

- let r = match (reference, mut_reference) {

- (true, true) => "&mut",

- (true, false) => "&",

- _ => return,

- };

- acc.push(InlayHint {

- range,

- kind: InlayKind::BindingModeHint,

- label: r.to_string().into(),

- tooltip: Some(InlayTooltip::String("Inferred binding mode".into())),

- });

- });

- match pat {

- ast::Pat::IdentPat(pat) if pat.ref_token().is_none() && pat.mut_token().is_none() => {

- let bm = sema.binding_mode_of_pat(pat)?;

- let bm = match bm {

- hir::BindingMode::Move => return None,

- hir::BindingMode::Ref(Mutability::Mut) => "ref mut",

- hir::BindingMode::Ref(Mutability::Shared) => "ref",

- };

- acc.push(InlayHint {

- range: pat.syntax().text_range(),

- kind: InlayKind::BindingModeHint,

- label: bm.to_string().into(),

- tooltip: Some(InlayTooltip::String("Inferred binding mode".into())),

- });

- }

- ast::Pat::OrPat(pat) if outer_paren_pat.is_none() => {

- acc.push(InlayHint {

- range: pat.syntax().text_range(),

- kind: InlayKind::OpeningParenthesis,

- label: "(".into(),

- tooltip: None,

- });

- acc.push(InlayHint {

- range: pat.syntax().text_range(),

- kind: InlayKind::ClosingParenthesis,

- label: ")".into(),

- tooltip: None,

- });

- }

- _ => (),

- }

-

- Some(())

-}

-

-fn bind_pat_hints(

- acc: &mut Vec<InlayHint>,

- sema: &Semantics<'_, RootDatabase>,

- config: &InlayHintsConfig,

- file_id: FileId,

- pat: &ast::IdentPat,

-) -> Option<()> {

- if !config.type_hints {

- return None;

- }

-

- let descended = sema.descend_node_into_attributes(pat.clone()).pop();

- let desc_pat = descended.as_ref().unwrap_or(pat);

- let ty = sema.type_of_pat(&desc_pat.clone().into())?.original;

-

- if should_not_display_type_hint(sema, config, pat, &ty) {

- return None;

- }

-

- let krate = sema.scope(desc_pat.syntax())?.krate();

- let famous_defs = FamousDefs(sema, krate);

- let label = hint_iterator(sema, &famous_defs, config, &ty);

-

- let label = match label {

- Some(label) => label,

- None => {

- let ty_name = ty.display_truncated(sema.db, config.max_length).to_string();

- if config.hide_named_constructor_hints

- && is_named_constructor(sema, pat, &ty_name).is_some()

- {

- return None;

- }

- ty_name

- }

- };

-

- acc.push(InlayHint {

- range: match pat.name() {

- Some(name) => name.syntax().text_range(),

- None => pat.syntax().text_range(),

- },

- kind: InlayKind::TypeHint,

- label: label.into(),

- tooltip: pat

- .name()

- .map(|it| it.syntax().text_range())

- .map(|it| InlayTooltip::HoverRanged(file_id, it)),

- });

-

- Some(())

-}

-

-fn is_named_constructor(

- sema: &Semantics<'_, RootDatabase>,

- pat: &ast::IdentPat,

- ty_name: &str,

-) -> Option<()> {

- let let_node = pat.syntax().parent()?;

- let expr = match_ast! {

- match let_node {

- ast::LetStmt(it) => it.initializer(),

- ast::LetExpr(it) => it.expr(),

- _ => None,

- }

- }?;

-

- let expr = sema.descend_node_into_attributes(expr.clone()).pop().unwrap_or(expr);

- // unwrap postfix expressions

- let expr = match expr {

- ast::Expr::TryExpr(it) => it.expr(),

- ast::Expr::AwaitExpr(it) => it.expr(),

- expr => Some(expr),

- }?;

- let expr = match expr {

- ast::Expr::CallExpr(call) => match call.expr()? {

- ast::Expr::PathExpr(path) => path,

- _ => return None,

- },

- ast::Expr::PathExpr(path) => path,

- _ => return None,

- };

- let path = expr.path()?;

-

- let callable = sema.type_of_expr(&ast::Expr::PathExpr(expr))?.original.as_callable(sema.db);

- let callable_kind = callable.map(|it| it.kind());

- let qual_seg = match callable_kind {

- Some(hir::CallableKind::Function(_) | hir::CallableKind::TupleEnumVariant(_)) => {

- path.qualifier()?.segment()

- }

- _ => path.segment(),

- }?;

-

- let ctor_name = match qual_seg.kind()? {

- ast::PathSegmentKind::Name(name_ref) => {

- match qual_seg.generic_arg_list().map(|it| it.generic_args()) {

- Some(generics) => format!("{}<{}>", name_ref, generics.format(", ")),

- None => name_ref.to_string(),

- }

- }

- ast::PathSegmentKind::Type { type_ref: Some(ty), trait_ref: None } => ty.to_string(),

- _ => return None,

- };

- (ctor_name == ty_name).then(|| ())

-}

-

-fn pat_is_enum_variant(db: &RootDatabase, bind_pat: &ast::IdentPat, pat_ty: &hir::Type) -> bool {

- if let Some(hir::Adt::Enum(enum_data)) = pat_ty.as_adt() {

- let pat_text = bind_pat.to_string();

- enum_data

- .variants(db)

- .into_iter()

- .map(|variant| variant.name(db).to_smol_str())

- .any(|enum_name| enum_name == pat_text)

- } else {

- false

- }

-}

-

-fn should_not_display_type_hint(

- sema: &Semantics<'_, RootDatabase>,

- config: &InlayHintsConfig,

- bind_pat: &ast::IdentPat,

- pat_ty: &hir::Type,

-) -> bool {

- let db = sema.db;

-

- if pat_ty.is_unknown() {

- return true;

- }

-

- if let Some(hir::Adt::Struct(s)) = pat_ty.as_adt() {

- if s.fields(db).is_empty() && s.name(db).to_smol_str() == bind_pat.to_string() {

- return true;

- }

- }

-

- if config.hide_closure_initialization_hints {

- if let Some(parent) = bind_pat.syntax().parent() {

- if let Some(it) = ast::LetStmt::cast(parent.clone()) {

- if let Some(ast::Expr::ClosureExpr(closure)) = it.initializer() {

- if closure_has_block_body(&closure) {

- return true;

- }

- }

- }

- }

- }

-

- for node in bind_pat.syntax().ancestors() {

- match_ast! {

- match node {

- ast::LetStmt(it) => return it.ty().is_some(),

- // FIXME: We might wanna show type hints in parameters for non-top level patterns as well

- ast::Param(it) => return it.ty().is_some(),

- ast::MatchArm(_) => return pat_is_enum_variant(db, bind_pat, pat_ty),

- ast::LetExpr(_) => return pat_is_enum_variant(db, bind_pat, pat_ty),

- ast::IfExpr(_) => return false,

- ast::WhileExpr(_) => return false,

- ast::ForExpr(it) => {

- // We *should* display hint only if user provided "in {expr}" and we know the type of expr (and it's not unit).

- // Type of expr should be iterable.

- return it.in_token().is_none() ||

- it.iterable()

- .and_then(|iterable_expr| sema.type_of_expr(&iterable_expr))

- .map(TypeInfo::original)

- .map_or(true, |iterable_ty| iterable_ty.is_unknown() || iterable_ty.is_unit())

- },

- _ => (),

- }

- }

- }

- false

-}

-

-fn should_hide_param_name_hint(

- sema: &Semantics<'_, RootDatabase>,

- callable: &hir::Callable,

- param_name: &str,

- argument: &ast::Expr,

-) -> bool {

- // These are to be tested in the `parameter_hint_heuristics` test

- // hide when:

- // - the parameter name is a suffix of the function's name

- // - the argument is a qualified constructing or call expression where the qualifier is an ADT

- // - exact argument<->parameter match(ignoring leading underscore) or parameter is a prefix/suffix

- // of argument with _ splitting it off

- // - param starts with `ra_fixture`

- // - param is a well known name in a unary function

-

- let param_name = param_name.trim_start_matches('_');

- if param_name.is_empty() {

- return true;

- }

-

- if matches!(argument, ast::Expr::PrefixExpr(prefix) if prefix.op_kind() == Some(UnaryOp::Not)) {

- return false;

- }

-

- let fn_name = match callable.kind() {

- hir::CallableKind::Function(it) => Some(it.name(sema.db).to_smol_str()),

- _ => None,

- };

- let fn_name = fn_name.as_deref();

- is_param_name_suffix_of_fn_name(param_name, callable, fn_name)

- || is_argument_similar_to_param_name(argument, param_name)

- || param_name.starts_with("ra_fixture")

- || (callable.n_params() == 1 && is_obvious_param(param_name))

- || is_adt_constructor_similar_to_param_name(sema, argument, param_name)

-}

-

-fn is_argument_similar_to_param_name(argument: &ast::Expr, param_name: &str) -> bool {

- // check whether param_name and argument are the same or

- // whether param_name is a prefix/suffix of argument(split at `_`)

- let argument = match get_string_representation(argument) {

- Some(argument) => argument,

- None => return false,

- };

-

- // std is honestly too panic happy...

- let str_split_at = |str: &str, at| str.is_char_boundary(at).then(|| argument.split_at(at));

-

- let param_name = param_name.trim_start_matches('_');

- let argument = argument.trim_start_matches('_');

-

- match str_split_at(argument, param_name.len()) {

- Some((prefix, rest)) if prefix.eq_ignore_ascii_case(param_name) => {

- return rest.is_empty() || rest.starts_with('_');

- }

- _ => (),

- }

- match argument.len().checked_sub(param_name.len()).and_then(|at| str_split_at(argument, at)) {

- Some((rest, suffix)) if param_name.eq_ignore_ascii_case(suffix) => {

- return rest.is_empty() || rest.ends_with('_');

- }

- _ => (),

- }

- false

-}

-

-/// Hide the parameter name of a unary function if it is a `_` - prefixed suffix of the function's name, or equal.

-///

-/// `fn strip_suffix(suffix)` will be hidden.

-/// `fn stripsuffix(suffix)` will not be hidden.

-fn is_param_name_suffix_of_fn_name(

- param_name: &str,

- callable: &Callable,

- fn_name: Option<&str>,

-) -> bool {

- match (callable.n_params(), fn_name) {

- (1, Some(function)) => {

- function == param_name

- || function

- .len()

- .checked_sub(param_name.len())

- .and_then(|at| function.is_char_boundary(at).then(|| function.split_at(at)))

- .map_or(false, |(prefix, suffix)| {

- suffix.eq_ignore_ascii_case(param_name) && prefix.ends_with('_')

- })

- }

- _ => false,

- }

-}

-

-fn is_adt_constructor_similar_to_param_name(

- sema: &Semantics<'_, RootDatabase>,

- argument: &ast::Expr,

- param_name: &str,

-) -> bool {

- let path = match argument {

- ast::Expr::CallExpr(c) => c.expr().and_then(|e| match e {

- ast::Expr::PathExpr(p) => p.path(),

- _ => None,

- }),

- ast::Expr::PathExpr(p) => p.path(),

- ast::Expr::RecordExpr(r) => r.path(),

- _ => return false,

- };

- let path = match path {

- Some(it) => it,

- None => return false,

- };

- (|| match sema.resolve_path(&path)? {

- hir::PathResolution::Def(hir::ModuleDef::Adt(_)) => {

- Some(to_lower_snake_case(&path.segment()?.name_ref()?.text()) == param_name)

- }

- hir::PathResolution::Def(hir::ModuleDef::Function(_) | hir::ModuleDef::Variant(_)) => {

- if to_lower_snake_case(&path.segment()?.name_ref()?.text()) == param_name {

- return Some(true);

- }

- let qual = path.qualifier()?;

- match sema.resolve_path(&qual)? {

- hir::PathResolution::Def(hir::ModuleDef::Adt(_)) => {

- Some(to_lower_snake_case(&qual.segment()?.name_ref()?.text()) == param_name)

- }

- _ => None,

- }

- }

- _ => None,

- })()

- .unwrap_or(false)

-}

-

-fn get_string_representation(expr: &ast::Expr) -> Option<String> {

- match expr {

- ast::Expr::MethodCallExpr(method_call_expr) => {

- let name_ref = method_call_expr.name_ref()?;

- match name_ref.text().as_str() {

- "clone" | "as_ref" => method_call_expr.receiver().map(|rec| rec.to_string()),

- name_ref => Some(name_ref.to_owned()),

- }

- }

- ast::Expr::MacroExpr(macro_expr) => {

- Some(macro_expr.macro_call()?.path()?.segment()?.to_string())

- }

- ast::Expr::FieldExpr(field_expr) => Some(field_expr.name_ref()?.to_string()),

- ast::Expr::PathExpr(path_expr) => Some(path_expr.path()?.segment()?.to_string()),

- ast::Expr::PrefixExpr(prefix_expr) => get_string_representation(&prefix_expr.expr()?),

- ast::Expr::RefExpr(ref_expr) => get_string_representation(&ref_expr.expr()?),

- ast::Expr::CastExpr(cast_expr) => get_string_representation(&cast_expr.expr()?),

- _ => None,

- }

-}

-

-fn is_obvious_param(param_name: &str) -> bool {

- // avoid displaying hints for common functions like map, filter, etc.

- // or other obvious words used in std

- let is_obvious_param_name =

- matches!(param_name, "predicate" | "value" | "pat" | "rhs" | "other");

- param_name.len() == 1 || is_obvious_param_name

-}

-

-fn get_callable(

- sema: &Semantics<'_, RootDatabase>,

- expr: &ast::Expr,

-) -> Option<(hir::Callable, ast::ArgList)> {

- match expr {

- ast::Expr::CallExpr(expr) => {

- let descended = sema.descend_node_into_attributes(expr.clone()).pop();

- let expr = descended.as_ref().unwrap_or(expr);

- sema.type_of_expr(&expr.expr()?)?.original.as_callable(sema.db).zip(expr.arg_list())

- }

- ast::Expr::MethodCallExpr(expr) => {

- let descended = sema.descend_node_into_attributes(expr.clone()).pop();

- let expr = descended.as_ref().unwrap_or(expr);

- sema.resolve_method_call_as_callable(expr).zip(expr.arg_list())

- }

- _ => None,

- }

-}

-