+use hir::known;
use ide_db::helpers::FamousDefs;
+use stdx::format_to;
use syntax::{
- ast::{self, edit::AstNodeEdit, make, ArgListOwner},
+ ast::{self, edit_in_place::Indent, make, HasArgList, HasLoopBody},
AstNode,
};
// Converts an Iterator::for_each function into a for loop.
//
// ```
-// # //- /lib.rs crate:core
-// # pub mod iter { pub mod traits { pub mod iterator { pub trait Iterator {} } } }
-// # pub struct SomeIter;
-// # impl self::iter::traits::iterator::Iterator for SomeIter {}
-// # //- /lib.rs crate:main deps:core
-// # use core::SomeIter;
+// # //- minicore: iterators
+// # use core::iter;
// fn main() {
-// let iter = SomeIter;
+// let iter = iter::repeat((9, 2));
// iter.for_each$0(|(x, y)| {
// println!("x: {}, y: {}", x, y);
// });
// ```
// ->
// ```
-// # use core::SomeIter;
+// # use core::iter;
// fn main() {
-// let iter = SomeIter;
+// let iter = iter::repeat((9, 2));
// for (x, y) in iter {
// println!("x: {}, y: {}", x, y);
// }
// }
// ```
-
pub(crate) fn convert_iter_for_each_to_for(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
let method = ctx.find_node_at_offset::<ast::MethodCallExpr>()?;
let body = closure.body()?;
let stmt = method.syntax().parent().and_then(ast::ExprStmt::cast);
- let syntax = stmt.as_ref().map_or(method.syntax(), |stmt| stmt.syntax());
+ let range = stmt.as_ref().map_or(method.syntax(), AstNode::syntax).text_range();
acc.add(
AssistId("convert_iter_for_each_to_for", AssistKind::RefactorRewrite),
"Replace this `Iterator::for_each` with a for loop",
- syntax.text_range(),
+ range,
|builder| {
- let indent = stmt.as_ref().map_or(method.indent_level(), |stmt| stmt.indent_level());
+ let indent =
+ stmt.as_ref().map_or_else(|| method.indent_level(), ast::ExprStmt::indent_level);
let block = match body {
ast::Expr::BlockExpr(block) => block,
_ => make::block_expr(Vec::new(), Some(body)),
}
- .reset_indent()
- .indent(indent);
+ .clone_for_update();
+ block.reindent_to(indent);
let expr_for_loop = make::expr_for_loop(param, receiver, block);
- builder.replace(syntax.text_range(), expr_for_loop.syntax().text())
+ builder.replace(range, expr_for_loop.to_string())
+ },
+ )
+}
+
+// Assist: convert_for_loop_with_for_each
+//
+// Converts a for loop into a for_each loop on the Iterator.
+//
+// ```
+// fn main() {
+// let x = vec![1, 2, 3];
+// for$0 v in x {
+// let y = v * 2;
+// }
+// }
+// ```
+// ->
+// ```
+// fn main() {
+// let x = vec![1, 2, 3];
+// x.into_iter().for_each(|v| {
+// let y = v * 2;
+// });
+// }
+// ```
+pub(crate) fn convert_for_loop_with_for_each(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+ let for_loop = ctx.find_node_at_offset::<ast::ForExpr>()?;
+ let iterable = for_loop.iterable()?;
+ let pat = for_loop.pat()?;
+ let body = for_loop.loop_body()?;
+ if body.syntax().text_range().start() < ctx.offset() {
+ cov_mark::hit!(not_available_in_body);
+ return None;
+ }
+
+ acc.add(
+ AssistId("convert_for_loop_with_for_each", AssistKind::RefactorRewrite),
+ "Replace this for loop with `Iterator::for_each`",
+ for_loop.syntax().text_range(),
+ |builder| {
+ let mut buf = String::new();
+
+ if let Some((expr_behind_ref, method)) =
+ is_ref_and_impls_iter_method(&ctx.sema, &iterable)
+ {
+ // We have either "for x in &col" and col implements a method called iter
+ // or "for x in &mut col" and col implements a method called iter_mut
+ format_to!(buf, "{}.{}()", expr_behind_ref, method);
+ } else if let ast::Expr::RangeExpr(..) = iterable {
+ // range expressions need to be parenthesized for the syntax to be correct
+ format_to!(buf, "({})", iterable);
+ } else if impls_core_iter(&ctx.sema, &iterable) {
+ format_to!(buf, "{}", iterable);
+ } else if let ast::Expr::RefExpr(_) = iterable {
+ format_to!(buf, "({}).into_iter()", iterable);
+ } else {
+ format_to!(buf, "{}.into_iter()", iterable);
+ }
+
+ format_to!(buf, ".for_each(|{}| {});", pat, body);
+
+ builder.replace(for_loop.syntax().text_range(), buf)
},
)
}
+/// If iterable is a reference where the expression behind the reference implements a method
+/// returning an Iterator called iter or iter_mut (depending on the type of reference) then return
+/// the expression behind the reference and the method name
+fn is_ref_and_impls_iter_method(
+ sema: &hir::Semantics<ide_db::RootDatabase>,
+ iterable: &ast::Expr,
+) -> Option<(ast::Expr, hir::Name)> {
+ let ref_expr = match iterable {
+ ast::Expr::RefExpr(r) => r,
+ _ => return None,
+ };
+ let wanted_method = if ref_expr.mut_token().is_some() { known::iter_mut } else { known::iter };
+ let expr_behind_ref = ref_expr.expr()?;
+ let ty = sema.type_of_expr(&expr_behind_ref)?.adjusted();
+ let scope = sema.scope(iterable.syntax());
+ let krate = scope.module()?.krate();
+ let traits_in_scope = scope.visible_traits();
+ let iter_trait = FamousDefs(sema, Some(krate)).core_iter_Iterator()?;
+
+ let has_wanted_method = ty
+ .iterate_method_candidates(
+ sema.db,
+ krate,
+ &traits_in_scope,
+ None,
+ Some(&wanted_method),
+ |_, func| {
+ if func.ret_type(sema.db).impls_trait(sema.db, iter_trait, &[]) {
+ return Some(());
+ }
+ None
+ },
+ )
+ .is_some();
+ if !has_wanted_method {
+ return None;
+ }
+
+ Some((expr_behind_ref, wanted_method))
+}
+
+/// Whether iterable implements core::Iterator
+fn impls_core_iter(sema: &hir::Semantics<ide_db::RootDatabase>, iterable: &ast::Expr) -> bool {
+ let it_typ = match sema.type_of_expr(iterable) {
+ Some(it) => it.adjusted(),
+ None => return false,
+ };
+
+ let module = match sema.scope(iterable.syntax()).module() {
+ Some(it) => it,
+ None => return false,
+ };
+
+ let krate = module.krate();
+ match FamousDefs(sema, Some(krate)).core_iter_Iterator() {
+ Some(iter_trait) => {
+ cov_mark::hit!(test_already_impls_iterator);
+ it_typ.impls_trait(sema.db, iter_trait, &[])
+ }
+ None => false,
+ }
+}
+
fn validate_method_call_expr(
ctx: &AssistContext,
expr: ast::MethodCallExpr,
) -> Option<(ast::Expr, ast::Expr)> {
let name_ref = expr.name_ref()?;
- if name_ref.syntax().text_range().intersect(ctx.frange.range).is_none() {
+ if !name_ref.syntax().text_range().contains_range(ctx.selection_trimmed()) {
cov_mark::hit!(test_for_each_not_applicable_invalid_cursor_pos);
return None;
}
let receiver = expr.receiver()?;
let expr = ast::Expr::MethodCallExpr(expr);
- let it_type = sema.type_of_expr(&receiver)?;
+ let it_type = sema.type_of_expr(&receiver)?.adjusted();
let module = sema.scope(receiver.syntax()).module()?;
let krate = module.krate();
}"#,
)
}
+
+ #[test]
+ fn each_to_for_not_for() {
+ check_assist_not_applicable(
+ convert_for_loop_with_for_each,
+ r"
+let mut x = vec![1, 2, 3];
+x.iter_mut().$0for_each(|v| *v *= 2);
+ ",
+ )
+ }
+
+ #[test]
+ fn each_to_for_simple_for() {
+ check_assist(
+ convert_for_loop_with_for_each,
+ r"
+fn main() {
+ let x = vec![1, 2, 3];
+ for $0v in x {
+ v *= 2;
+ }
+}",
+ r"
+fn main() {
+ let x = vec![1, 2, 3];
+ x.into_iter().for_each(|v| {
+ v *= 2;
+ });
+}",
+ )
+ }
+
+ #[test]
+ fn each_to_for_for_in_range() {
+ check_assist(
+ convert_for_loop_with_for_each,
+ r#"
+//- minicore: range, iterators
+impl<T> core::iter::Iterator for core::ops::Range<T> {
+ type Item = T;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ None
+ }
+}
+
+fn main() {
+ for $0x in 0..92 {
+ print!("{}", x);
+ }
+}"#,
+ r#"
+impl<T> core::iter::Iterator for core::ops::Range<T> {
+ type Item = T;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ None
+ }
+}
+
+fn main() {
+ (0..92).for_each(|x| {
+ print!("{}", x);
+ });
+}"#,
+ )
+ }
+
+ #[test]
+ fn each_to_for_not_available_in_body() {
+ cov_mark::check!(not_available_in_body);
+ check_assist_not_applicable(
+ convert_for_loop_with_for_each,
+ r"
+fn main() {
+ let x = vec![1, 2, 3];
+ for v in x {
+ $0v *= 2;
+ }
+}",
+ )
+ }
+
+ #[test]
+ fn each_to_for_for_borrowed() {
+ check_assist(
+ convert_for_loop_with_for_each,
+ r#"
+//- minicore: iterators
+use core::iter::{Repeat, repeat};
+
+struct S;
+impl S {
+ fn iter(&self) -> Repeat<i32> { repeat(92) }
+ fn iter_mut(&mut self) -> Repeat<i32> { repeat(92) }
+}
+
+fn main() {
+ let x = S;
+ for $0v in &x {
+ let a = v * 2;
+ }
+}
+"#,
+ r#"
+use core::iter::{Repeat, repeat};
+
+struct S;
+impl S {
+ fn iter(&self) -> Repeat<i32> { repeat(92) }
+ fn iter_mut(&mut self) -> Repeat<i32> { repeat(92) }
+}
+
+fn main() {
+ let x = S;
+ x.iter().for_each(|v| {
+ let a = v * 2;
+ });
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn each_to_for_for_borrowed_no_iter_method() {
+ check_assist(
+ convert_for_loop_with_for_each,
+ r"
+struct NoIterMethod;
+fn main() {
+ let x = NoIterMethod;
+ for $0v in &x {
+ let a = v * 2;
+ }
+}
+",
+ r"
+struct NoIterMethod;
+fn main() {
+ let x = NoIterMethod;
+ (&x).into_iter().for_each(|v| {
+ let a = v * 2;
+ });
+}
+",
+ )
+ }
+
+ #[test]
+ fn each_to_for_for_borrowed_mut() {
+ check_assist(
+ convert_for_loop_with_for_each,
+ r#"
+//- minicore: iterators
+use core::iter::{Repeat, repeat};
+
+struct S;
+impl S {
+ fn iter(&self) -> Repeat<i32> { repeat(92) }
+ fn iter_mut(&mut self) -> Repeat<i32> { repeat(92) }
+}
+
+fn main() {
+ let x = S;
+ for $0v in &mut x {
+ let a = v * 2;
+ }
+}
+"#,
+ r#"
+use core::iter::{Repeat, repeat};
+
+struct S;
+impl S {
+ fn iter(&self) -> Repeat<i32> { repeat(92) }
+ fn iter_mut(&mut self) -> Repeat<i32> { repeat(92) }
+}
+
+fn main() {
+ let x = S;
+ x.iter_mut().for_each(|v| {
+ let a = v * 2;
+ });
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn each_to_for_for_borrowed_mut_behind_var() {
+ check_assist(
+ convert_for_loop_with_for_each,
+ r"
+fn main() {
+ let x = vec![1, 2, 3];
+ let y = &mut x;
+ for $0v in y {
+ *v *= 2;
+ }
+}",
+ r"
+fn main() {
+ let x = vec![1, 2, 3];
+ let y = &mut x;
+ y.into_iter().for_each(|v| {
+ *v *= 2;
+ });
+}",
+ )
+ }
+
+ #[test]
+ fn each_to_for_already_impls_iterator() {
+ cov_mark::check!(test_already_impls_iterator);
+ check_assist(
+ convert_for_loop_with_for_each,
+ r#"
+//- minicore: iterators
+fn main() {
+ for$0 a in core::iter::repeat(92).take(1) {
+ println!("{}", a);
+ }
+}
+"#,
+ r#"
+fn main() {
+ core::iter::repeat(92).take(1).for_each(|a| {
+ println!("{}", a);
+ });
+}
+"#,
+ );
+ }
}