unify the lints

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Oliver Schneider 2016-06-22 10:44:46 +02:00
parent ac6e7b2957
commit 5ccbf3d437
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5 changed files with 30 additions and 42 deletions

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@ -154,9 +154,7 @@ All notable changes to this project will be documented in this file.
[`explicit_counter_loop`]: https://github.com/Manishearth/rust-clippy/wiki#explicit_counter_loop
[`explicit_iter_loop`]: https://github.com/Manishearth/rust-clippy/wiki#explicit_iter_loop
[`extend_from_slice`]: https://github.com/Manishearth/rust-clippy/wiki#extend_from_slice
[`filter_flat_map`]: https://github.com/Manishearth/rust-clippy/wiki#filter_flat_map
[`filter_map`]: https://github.com/Manishearth/rust-clippy/wiki#filter_map
[`filter_map_flat_map`]: https://github.com/Manishearth/rust-clippy/wiki#filter_map_flat_map
[`filter_next`]: https://github.com/Manishearth/rust-clippy/wiki#filter_next
[`float_arithmetic`]: https://github.com/Manishearth/rust-clippy/wiki#float_arithmetic
[`float_cmp`]: https://github.com/Manishearth/rust-clippy/wiki#float_cmp

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@ -17,7 +17,7 @@ Table of contents:
## Lints
There are 157 lints included in this crate:
There are 155 lints included in this crate:
name | default | meaning
---------------------------------------------------------------------------------------------------------------------|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
@ -60,9 +60,7 @@ name
[explicit_counter_loop](https://github.com/Manishearth/rust-clippy/wiki#explicit_counter_loop) | warn | for-looping with an explicit counter when `_.enumerate()` would do
[explicit_iter_loop](https://github.com/Manishearth/rust-clippy/wiki#explicit_iter_loop) | warn | for-looping over `_.iter()` or `_.iter_mut()` when `&_` or `&mut _` would do
[extend_from_slice](https://github.com/Manishearth/rust-clippy/wiki#extend_from_slice) | warn | `.extend_from_slice(_)` is a faster way to extend a Vec by a slice
[filter_flat_map](https://github.com/Manishearth/rust-clippy/wiki#filter_flat_map) | allow | using `filter(_).flat_map(_)`, which can be rewritten using just the flat_map
[filter_map](https://github.com/Manishearth/rust-clippy/wiki#filter_map) | allow | using `filter(_).map(_)`, which is more succinctly expressed as `.filter_map(_)`
[filter_map_flat_map](https://github.com/Manishearth/rust-clippy/wiki#filter_map_flat_map) | allow | using `filter_map(_).flat_map(_)`, which can be rewritten using just the flat_map
[filter_next](https://github.com/Manishearth/rust-clippy/wiki#filter_next) | warn | using `filter(p).next()`, which is more succinctly expressed as `.find(p)`
[float_arithmetic](https://github.com/Manishearth/rust-clippy/wiki#float_arithmetic) | allow | Any floating-point arithmetic statement
[float_cmp](https://github.com/Manishearth/rust-clippy/wiki#float_cmp) | warn | using `==` or `!=` on float values (as floating-point operations usually involve rounding errors, it is always better to check for approximate equality within small bounds)

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@ -268,9 +268,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
items_after_statements::ITEMS_AFTER_STATEMENTS,
matches::SINGLE_MATCH_ELSE,
mem_forget::MEM_FORGET,
methods::FILTER_FLAT_MAP,
methods::FILTER_MAP,
methods::FILTER_MAP_FLAT_MAP,
methods::OPTION_UNWRAP_USED,
methods::RESULT_UNWRAP_USED,
methods::WRONG_PUB_SELF_CONVENTION,

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@ -159,11 +159,11 @@ declare_lint! {
"using `filter(p).next()`, which is more succinctly expressed as `.find(p)`"
}
/// **What it does:** This lint `Warn`s on `_.filter(_).map(_)`.
/// **What it does:** This lint `Warn`s on `_.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(_)`.
/// **Why is this bad?** Readability, this can be written more concisely as a single method call
///
/// **Known problems:** Often requires a condition + Option creation in `filter_map`
/// **Known problems:** Often requires a condition + Option/Iterator creation inside the closure
///
/// **Example:** `iter.filter(|x| x == 0).map(|x| x * 2)`
declare_lint! {
@ -171,30 +171,6 @@ declare_lint! {
"using `filter(_).map(_)`, which is more succinctly expressed as `.filter_map(_)`"
}
/// **What it does:** This lint `Warn`s on `_.filter(_).flat_map(_)`.
///
/// **Why is this bad?** Readability, this just needs the `flat_map` to return an empty iterator, if the value should be filtered.
///
/// **Known problems:** Often requires a condition + Iterator creation in `flat_map`
///
/// **Example:** `iter.filter(|x| x == 0).flat_map(|x| x.bits())`
declare_lint! {
pub FILTER_FLAT_MAP, Allow,
"using `filter(_).flat_map(_)`, which can be rewritten using just the flat_map"
}
/// **What it does:** This lint `Warn`s on `_.filter_map(_).flat_map(_)`.
///
/// **Why is this bad?** Readability, this just needs the `flat_map` to return an empty iterator, if the value should be filtered.
///
/// **Known problems:** Often requires a condition + Iterator creation in `flat_map`
///
/// **Example:** `iter.filter_map(|x| x.process()).flat_map(|x| x.bits())`
declare_lint! {
pub FILTER_MAP_FLAT_MAP, Allow,
"using `filter_map(_).flat_map(_)`, which can be rewritten using just the flat_map"
}
/// **What it does:** This lint `Warn`s on an iterator search (such as `find()`, `position()`, or
/// `rposition()`) followed by a call to `is_some()`.
///
@ -393,8 +369,6 @@ impl LintPass for Pass {
SEARCH_IS_SOME,
TEMPORARY_CSTRING_AS_PTR,
FILTER_MAP,
FILTER_FLAT_MAP,
FILTER_MAP_FLAT_MAP,
ITER_NTH)
}
}
@ -420,6 +394,8 @@ impl LateLintPass for Pass {
lint_filter_next(cx, expr, arglists[0]);
} else if let Some(arglists) = method_chain_args(expr, &["filter", "map"]) {
lint_filter_map(cx, expr, arglists[0], arglists[1]);
} else if let Some(arglists) = method_chain_args(expr, &["filter_map", "map"]) {
lint_filter_map_map(cx, expr, arglists[0], arglists[1]);
} else if let Some(arglists) = method_chain_args(expr, &["filter", "flat_map"]) {
lint_filter_flat_map(cx, expr, arglists[0], arglists[1]);
} else if let Some(arglists) = method_chain_args(expr, &["filter_map", "flat_map"]) {
@ -884,8 +860,19 @@ fn lint_filter_next(cx: &LateContext, expr: &hir::Expr, filter_args: &MethodArgs
fn lint_filter_map(cx: &LateContext, expr: &hir::Expr, _filter_args: &MethodArgs, _map_args: &MethodArgs) {
// lint if caller of `.filter().map()` is an Iterator
if match_trait_method(cx, expr, &paths::ITERATOR) {
let msg = "called `filter(p).map(q)` on an `Iterator`. This is more succinctly expressed by calling `.filter_map(..)` \
instead.";
let msg = "called `filter(p).map(q)` on an `Iterator`. \
This is more succinctly expressed by calling `.filter_map(..)` instead.";
span_lint(cx, FILTER_MAP, expr.span, msg);
}
}
// Type of MethodArgs is potentially a Vec
/// lint use of `filter().map()` for `Iterators`
fn lint_filter_map_map(cx: &LateContext, expr: &hir::Expr, _filter_args: &MethodArgs, _map_args: &MethodArgs) {
// lint if caller of `.filter().map()` is an Iterator
if match_trait_method(cx, expr, &paths::ITERATOR) {
let msg = "called `filter_map(p).map(q)` on an `Iterator`. \
This is more succinctly expressed by only calling `.filter_map(..)` instead.";
span_lint(cx, FILTER_MAP, expr.span, msg);
}
}
@ -895,9 +882,10 @@ fn lint_filter_map(cx: &LateContext, expr: &hir::Expr, _filter_args: &MethodArgs
fn lint_filter_flat_map(cx: &LateContext, expr: &hir::Expr, _filter_args: &MethodArgs, _map_args: &MethodArgs) {
// lint if caller of `.filter().flat_map()` is an Iterator
if match_trait_method(cx, expr, &paths::ITERATOR) {
let msg = "called `filter(p).flat_map(q)` on an `Iterator`. This is more succinctly expressed by calling `.flat_map(..)` \
let msg = "called `filter(p).flat_map(q)` on an `Iterator`. \
This is more succinctly expressed by calling `.flat_map(..)` \
and filtering by returning an empty Iterator.";
span_lint(cx, FILTER_FLAT_MAP, expr.span, msg);
span_lint(cx, FILTER_MAP, expr.span, msg);
}
}
@ -906,9 +894,10 @@ fn lint_filter_flat_map(cx: &LateContext, expr: &hir::Expr, _filter_args: &Metho
fn lint_filter_map_flat_map(cx: &LateContext, expr: &hir::Expr, _filter_args: &MethodArgs, _map_args: &MethodArgs) {
// lint if caller of `.filter_map().flat_map()` is an Iterator
if match_trait_method(cx, expr, &paths::ITERATOR) {
let msg = "called `filter_map(p).flat_map(q)` on an `Iterator`. This is more succinctly expressed by calling `.flat_map(..)` \
let msg = "called `filter_map(p).flat_map(q)` on an `Iterator`. \
This is more succinctly expressed by calling `.flat_map(..)` \
and filtering by returning an empty Iterator.";
span_lint(cx, FILTER_MAP_FLAT_MAP, expr.span, msg);
span_lint(cx, FILTER_MAP, expr.span, msg);
}
}

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@ -17,4 +17,9 @@ fn main() {
.filter_map(|x| x.checked_mul(2))
.flat_map(|x| x.checked_mul(2))
.collect();
let _: Vec<_> = vec![5i8; 6].into_iter() //~ERROR called `filter_map(p).map(q)` on an `Iterator`
.filter_map(|x| x.checked_mul(2))
.map(|x| x.checked_mul(2))
.collect();
}