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Diffstat (limited to 'crates/ide/src/inlay_hints/fn_lifetime_fn.rs')
| -rw-r--r-- | crates/ide/src/inlay_hints/fn_lifetime_fn.rs | 332 |
1 files changed, 0 insertions, 332 deletions
diff --git a/crates/ide/src/inlay_hints/fn_lifetime_fn.rs b/crates/ide/src/inlay_hints/fn_lifetime_fn.rs deleted file mode 100644 index d3666754e2..0000000000 --- a/crates/ide/src/inlay_hints/fn_lifetime_fn.rs +++ /dev/null @@ -1,332 +0,0 @@ -//! Implementation of "lifetime elision" inlay hints: -//! ```no_run -//! fn example/* <'0> */(a: &/* '0 */()) {} -//! ``` -use ide_db::{syntax_helpers::node_ext::walk_ty, FxHashMap}; -use itertools::Itertools; -use syntax::{ - ast::{self, AstNode, HasGenericParams, HasName}, - SyntaxToken, -}; -use syntax::{format_smolstr, SmolStr}; - -use crate::{InlayHint, InlayHintPosition, InlayHintsConfig, InlayKind, LifetimeElisionHints}; - -pub(super) 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::Lifetime, - label: label.into(), - text_edit: None, - position: InlayHintPosition::After, - pad_left: false, - pad_right: true, - }; - - 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, - )); - false - } - ast::Type::FnPtrType(_) => true, - ast::Type::PathType(t) => { - t.path().and_then(|it| it.segment()).and_then(|it| it.param_list()).is_some() - } - _ => false, - }) - }); - 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_smolstr!("'{idx}"), - }); - 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 self_param.is_some() && potential_lt_refs.next().is_some() { - 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.first().cloned(), - "'static" => None, - name => Some(name.into()), - }, - None => allocated_lifetimes.first().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())); - } - false - } - ast::Type::FnPtrType(_) => true, - ast::Type::PathType(t) => { - t.path().and_then(|it| it.segment()).and_then(|it| it.param_list()).is_some() - } - _ => false, - }) - } - } - - 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::Lifetime, - label: format!( - "{}{}", - allocated_lifetimes.iter().format(", "), - if is_empty { "" } else { ", " } - ) - .into(), - text_edit: None, - position: InlayHintPosition::After, - pad_left: false, - pad_right: true, - }); - } - (None, allocated_lifetimes) => acc.push(InlayHint { - range: func.name()?.syntax().text_range(), - kind: InlayKind::GenericParamList, - label: format!("<{}>", allocated_lifetimes.iter().format(", "),).into(), - text_edit: None, - position: InlayHintPosition::After, - pad_left: false, - pad_right: false, - }), - } - Some(()) -} - -#[cfg(test)] -mod tests { - use crate::{ - inlay_hints::tests::{check, check_with_config, TEST_CONFIG}, - InlayHintsConfig, LifetimeElisionHints, - }; - - #[test] - fn hints_lifetimes() { - check( - r#" -fn empty() {} - -fn no_gpl(a: &()) {} - //^^^^^^<'0> - // ^'0 -fn empty_gpl<>(a: &()) {} - // ^'0 ^'0 -fn partial<'b>(a: &(), b: &'b ()) {} -// ^'0, $ ^'0 -fn partial<'a>(a: &'a (), b: &()) {} -// ^'0, $ ^'0 - -fn single_ret(a: &()) -> &() {} -// ^^^^^^^^^^<'0> - // ^'0 ^'0 -fn full_mul(a: &(), b: &()) {} -// ^^^^^^^^<'0, '1> - // ^'0 ^'1 - -fn foo<'c>(a: &'c ()) -> &() {} - // ^'c - -fn nested_in(a: & &X< &()>) {} -// ^^^^^^^^^<'0, '1, '2> - //^'0 ^'1 ^'2 -fn nested_out(a: &()) -> & &X< &()>{} -// ^^^^^^^^^^<'0> - //^'0 ^'0 ^'0 ^'0 - -impl () { - fn foo(&self) {} - // ^^^<'0> - // ^'0 - fn foo(&self) -> &() {} - // ^^^<'0> - // ^'0 ^'0 - fn foo(&self, a: &()) -> &() {} - // ^^^<'0, '1> - // ^'0 ^'1 ^'0 -} -"#, - ); - } - - #[test] - fn hints_lifetimes_named() { - check_with_config( - InlayHintsConfig { param_names_for_lifetime_elision_hints: true, ..TEST_CONFIG }, - r#" -fn nested_in<'named>(named: & &X< &()>) {} -// ^'named1, 'named2, 'named3, $ - //^'named1 ^'named2 ^'named3 -"#, - ); - } - - #[test] - fn hints_lifetimes_trivial_skip() { - check_with_config( - InlayHintsConfig { - lifetime_elision_hints: LifetimeElisionHints::SkipTrivial, - ..TEST_CONFIG - }, - r#" -fn no_gpl(a: &()) {} -fn empty_gpl<>(a: &()) {} -fn partial<'b>(a: &(), b: &'b ()) {} -fn partial<'a>(a: &'a (), b: &()) {} - -fn single_ret(a: &()) -> &() {} -// ^^^^^^^^^^<'0> - // ^'0 ^'0 -fn full_mul(a: &(), b: &()) {} - -fn foo<'c>(a: &'c ()) -> &() {} - // ^'c - -fn nested_in(a: & &X< &()>) {} -fn nested_out(a: &()) -> & &X< &()>{} -// ^^^^^^^^^^<'0> - //^'0 ^'0 ^'0 ^'0 - -impl () { - fn foo(&self) {} - fn foo(&self) -> &() {} - // ^^^<'0> - // ^'0 ^'0 - fn foo(&self, a: &()) -> &() {} - // ^^^<'0, '1> - // ^'0 ^'1 ^'0 -} -"#, - ); - } - - #[test] - fn hints_lifetimes_skip_fn_likes() { - check_with_config( - InlayHintsConfig { - lifetime_elision_hints: LifetimeElisionHints::Always, - ..TEST_CONFIG - }, - r#" -fn fn_ptr(a: fn(&()) -> &()) {} -fn fn_trait<>(a: impl Fn(&()) -> &()) {} -"#, - ); - } -} |