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Deprecate filter_map

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This commit is contained in:
Cameron Steffen 2021-04-09 16:25:39 -05:00
parent 75efc144e7
commit a45faf66f3
12 changed files with 23 additions and 161 deletions
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9
clippy_lints/src/deprecated_lints.rs
View file

@ -188,3 +188,12 @@ declare_deprecated_lint! {
pub FIND_MAP,
"this lint has been replaced by `manual_find_map`, a more specific lint"
}
declare_deprecated_lint! {
/// **What it does:** Nothing. This lint has been deprecated.
///
/// **Deprecation reason:** This lint has been replaced by `manual_filter_map`, a
/// more specific lint.
pub FILTER_MAP,
"this lint has been replaced by `manual_filter_map`, a more specific lint"
}

6
clippy_lints/src/lib.rs
View file

@ -537,6 +537,10 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
"clippy::find_map",
"this lint has been replaced by `manual_find_map`, a more specific lint",
);
store.register_removed(
"clippy::filter_map",
"this lint has been replaced by `manual_filter_map`, a more specific lint",
);
// end deprecated lints, do not remove this comment, it’s used in `update_lints`
// begin register lints, do not remove this comment, it’s used in `update_lints`
@ -788,7 +792,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
methods::EXPECT_FUN_CALL,
methods::EXPECT_USED,
methods::FILETYPE_IS_FILE,
methods::FILTER_MAP,
methods::FILTER_MAP_IDENTITY,
methods::FILTER_MAP_NEXT,
methods::FILTER_NEXT,
@ -1404,7 +1407,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
LintId::of(matches::MATCH_WILDCARD_FOR_SINGLE_VARIANTS),
LintId::of(matches::MATCH_WILD_ERR_ARM),
LintId::of(matches::SINGLE_MATCH_ELSE),
LintId::of(methods::FILTER_MAP),
LintId::of(methods::FILTER_MAP_NEXT),
LintId::of(methods::IMPLICIT_CLONE),
LintId::of(methods::INEFFICIENT_TO_STRING),

18
clippy_lints/src/methods/filter_flat_map.rs
View file

@ -1,18 +0,0 @@
use clippy_utils::diagnostics::span_lint_and_help;
use clippy_utils::is_trait_method;
use rustc_hir as hir;
use rustc_lint::LateContext;
use rustc_span::sym;
use super::FILTER_MAP;
/// lint use of `filter().flat_map()` for `Iterators`
pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
// lint if caller of `.filter().flat_map()` is an Iterator
if is_trait_method(cx, expr, sym::Iterator) {
let msg = "called `filter(..).flat_map(..)` on an `Iterator`";
let hint = "this is more succinctly expressed by calling `.flat_map(..)` \
and filtering by returning `iter::empty()`";
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint);
}
}

18
clippy_lints/src/methods/filter_map_flat_map.rs
View file

@ -1,18 +0,0 @@
use clippy_utils::diagnostics::span_lint_and_help;
use clippy_utils::is_trait_method;
use rustc_hir as hir;
use rustc_lint::LateContext;
use rustc_span::sym;
use super::FILTER_MAP;
/// lint use of `filter_map().flat_map()` for `Iterators`
pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
// lint if caller of `.filter_map().flat_map()` is an Iterator
if is_trait_method(cx, expr, sym::Iterator) {
let msg = "called `filter_map(..).flat_map(..)` on an `Iterator`";
let hint = "this is more succinctly expressed by calling `.flat_map(..)` \
and filtering by returning `iter::empty()`";
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint);
}
}

17
clippy_lints/src/methods/filter_map_map.rs
View file

@ -1,17 +0,0 @@
use clippy_utils::diagnostics::span_lint_and_help;
use clippy_utils::is_trait_method;
use rustc_hir as hir;
use rustc_lint::LateContext;
use rustc_span::sym;
use super::FILTER_MAP;
/// lint use of `filter_map().map()` for `Iterators`
pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
// lint if caller of `.filter_map().map()` is an Iterator
if is_trait_method(cx, expr, sym::Iterator) {
let msg = "called `filter_map(..).map(..)` on an `Iterator`";
let hint = "this is more succinctly expressed by only calling `.filter_map(..)` instead";
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint);
}
}

40
clippy_lints/src/methods/mod.rs
View file

@ -11,11 +11,8 @@ mod clone_on_ref_ptr;
mod expect_fun_call;
mod expect_used;
mod filetype_is_file;
mod filter_flat_map;
mod filter_map;
mod filter_map_flat_map;
mod filter_map_identity;
mod filter_map_map;
mod filter_map_next;
mod filter_next;
mod flat_map_identity;
@ -472,35 +469,6 @@ declare_clippy_lint! {
"using combinations of `flatten` and `map` which can usually be written as a single method call"
}
declare_clippy_lint! {
/// **What it does:** Checks for usage of `_.filter(_).map(_)`,
/// `_.filter(_).flat_map(_)`, `_.filter_map(_).flat_map(_)` and similar.
///
/// **Why is this bad?** Readability, this can be written more concisely as
/// `_.filter_map(_)`.
///
/// **Known problems:** Often requires a condition + Option/Iterator creation
/// inside the closure.
///
/// **Example:**
/// ```rust
/// let vec = vec![1];
///
/// // Bad
/// vec.iter().filter(|x| **x == 0).map(|x| *x * 2);
///
/// // Good
/// vec.iter().filter_map(|x| if *x == 0 {
/// Some(*x * 2)
/// } else {
/// None
/// });
/// ```
pub FILTER_MAP,
pedantic,
"using combinations of `filter`, `map`, `filter_map` and `flat_map` which can usually be written as a single method call"
}
declare_clippy_lint! {
/// **What it does:** Checks for usage of `_.filter(_).map(_)` that can be written more simply
/// as `filter_map(_)`.
@ -1677,7 +1645,6 @@ impl_lint_pass!(Methods => [
SEARCH_IS_SOME,
FILTER_NEXT,
SKIP_WHILE_NEXT,
FILTER_MAP,
FILTER_MAP_IDENTITY,
MANUAL_FILTER_MAP,
MANUAL_FIND_MAP,
@ -1965,11 +1932,7 @@ fn check_methods<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, msrv: Optio
unnecessary_filter_map::check(cx, expr, arg);
filter_map_identity::check(cx, expr, arg, span);
},
("flat_map", [flm_arg]) => match method_call!(recv) {
Some(("filter", [_, _], _)) => filter_flat_map::check(cx, expr),
Some(("filter_map", [_, _], _)) => filter_map_flat_map::check(cx, expr),
_ => flat_map_identity::check(cx, expr, flm_arg, span),
},
("flat_map", [flm_arg]) => flat_map_identity::check(cx, expr, flm_arg, span),
("flatten", []) => {
if let Some(("map", [recv, map_arg], _)) = method_call!(recv) {
map_flatten::check(cx, expr, recv, map_arg);
@ -1993,7 +1956,6 @@ fn check_methods<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, msrv: Optio
("filter", [f_arg]) => {
filter_map::check(cx, expr, recv2, f_arg, span2, recv, m_arg, span, false)
},
("filter_map", [_]) => filter_map_map::check(cx, expr),
("find", [f_arg]) => filter_map::check(cx, expr, recv2, f_arg, span2, recv, m_arg, span, true),
_ => {},
}

1
clippy_utils/src/attrs.rs
View file

@ -151,7 +151,6 @@ pub fn is_proc_macro(sess: &Session, attrs: &[ast::Attribute]) -> bool {
/// Return true if the attributes contain `#[doc(hidden)]`
pub fn is_doc_hidden(attrs: &[ast::Attribute]) -> bool {
#[allow(clippy::filter_map)]
attrs
.iter()
.filter(|attr| attr.has_name(sym::doc))

2
lintcheck/src/main.rs
View file

@ -5,7 +5,7 @@
// When a new lint is introduced, we can search the results for new warnings and check for false
// positives.
#![allow(clippy::filter_map, clippy::collapsible_else_if)]
#![allow(clippy::collapsible_else_if)]
use std::ffi::OsStr;
use std::process::Command;

1
tests/ui/deprecated.rs
View file

@ -11,5 +11,6 @@
#[warn(clippy::panic_params)]
#[warn(clippy::unknown_clippy_lints)]
#[warn(clippy::find_map)]
#[warn(clippy::filter_map)]
fn main() {}

8
tests/ui/deprecated.stderr
View file

@ -78,11 +78,17 @@ error: lint `clippy::find_map` has been removed: this lint has been replaced by
LL | #[warn(clippy::find_map)]
| ^^^^^^^^^^^^^^^^
error: lint `clippy::filter_map` has been removed: this lint has been replaced by `manual_filter_map`, a more specific lint
--> $DIR/deprecated.rs:14:8
|
LL | #[warn(clippy::filter_map)]
| ^^^^^^^^^^^^^^^^^^
error: lint `clippy::unstable_as_slice` has been removed: `Vec::as_slice` has been stabilized in 1.7
--> $DIR/deprecated.rs:1:8
|
LL | #[warn(clippy::unstable_as_slice)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^
error: aborting due to 14 previous errors
error: aborting due to 15 previous errors

25
tests/ui/filter_methods.rs
View file

@ -1,25 +0,0 @@
#![warn(clippy::all, clippy::pedantic)]
#![allow(clippy::clippy::let_underscore_drop)]
#![allow(clippy::missing_docs_in_private_items)]
fn main() {
let _: Vec<_> = vec![5; 6].into_iter().filter(|&x| x == 0).map(|x| x * 2).collect();
let _: Vec<_> = vec![5_i8; 6]
.into_iter()
.filter(|&x| x == 0)
.flat_map(|x| x.checked_mul(2))
.collect();
let _: Vec<_> = vec![5_i8; 6]
.into_iter()
.filter_map(|x| x.checked_mul(2))
.flat_map(|x| x.checked_mul(2))
.collect();
let _: Vec<_> = vec![5_i8; 6]
.into_iter()
.filter_map(|x| x.checked_mul(2))
.map(|x| x.checked_mul(2))
.collect();
}

39
tests/ui/filter_methods.stderr
View file

@ -1,39 +0,0 @@
error: called `filter(..).flat_map(..)` on an `Iterator`
--> $DIR/filter_methods.rs:8:21
|
LL | let _: Vec<_> = vec![5_i8; 6]
| _____________________^
LL | | .into_iter()
LL | | .filter(|&x| x == 0)
LL | | .flat_map(|x| x.checked_mul(2))
| |_______________________________________^
|
= note: `-D clippy::filter-map` implied by `-D warnings`
= help: this is more succinctly expressed by calling `.flat_map(..)` and filtering by returning `iter::empty()`
error: called `filter_map(..).flat_map(..)` on an `Iterator`
--> $DIR/filter_methods.rs:14:21
|
LL | let _: Vec<_> = vec![5_i8; 6]
| _____________________^
LL | | .into_iter()
LL | | .filter_map(|x| x.checked_mul(2))
LL | | .flat_map(|x| x.checked_mul(2))
| |_______________________________________^
|
= help: this is more succinctly expressed by calling `.flat_map(..)` and filtering by returning `iter::empty()`
error: called `filter_map(..).map(..)` on an `Iterator`
--> $DIR/filter_methods.rs:20:21
|
LL | let _: Vec<_> = vec![5_i8; 6]
| _____________________^
LL | | .into_iter()
LL | | .filter_map(|x| x.checked_mul(2))
LL | | .map(|x| x.checked_mul(2))
| |__________________________________^
|
= help: this is more succinctly expressed by only calling `.filter_map(..)` instead
error: aborting due to 3 previous errors