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use super::FOR_LOOPS_OVER_FALLIBLES;
use clippy_utils::diagnostics::span_lint_and_help;
use clippy_utils::source::snippet;
use clippy_utils::ty::is_type_diagnostic_item;
use rustc_hir::{Expr, Pat};
use rustc_lint::LateContext;
use rustc_span::symbol::sym;
/// Checks for `for` loops over `Option`s and `Result`s.
pub(super) fn check(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>, method_name: Option<&str>) {
let ty = cx.typeck_results().expr_ty(arg);
if is_type_diagnostic_item(cx, ty, sym::Option) {
let help_string = if let Some(method_name) = method_name {
format!(
"consider replacing `for {0} in {1}.{method_name}()` with `if let Some({0}) = {1}`",
snippet(cx, pat.span, "_"),
snippet(cx, arg.span, "_")
)
} else {
format!(
"consider replacing `for {0} in {1}` with `if let Some({0}) = {1}`",
snippet(cx, pat.span, "_"),
snippet(cx, arg.span, "_")
)
};
span_lint_and_help(
cx,
FOR_LOOPS_OVER_FALLIBLES,
arg.span,
&format!(
"for loop over `{0}`, which is an `Option`. This is more readably written as an \
`if let` statement",
snippet(cx, arg.span, "_")
),
None,
&help_string,
);
} else if is_type_diagnostic_item(cx, ty, sym::Result) {
let help_string = if let Some(method_name) = method_name {
format!(
"consider replacing `for {0} in {1}.{method_name}()` with `if let Ok({0}) = {1}`",
snippet(cx, pat.span, "_"),
snippet(cx, arg.span, "_")
)
} else {
format!(
"consider replacing `for {0} in {1}` with `if let Ok({0}) = {1}`",
snippet(cx, pat.span, "_"),
snippet(cx, arg.span, "_")
)
};
span_lint_and_help(
cx,
FOR_LOOPS_OVER_FALLIBLES,
arg.span,
&format!(
"for loop over `{0}`, which is a `Result`. This is more readably written as an \
`if let` statement",
snippet(cx, arg.span, "_")
),
None,
&help_string,
);
}
}
|
