// Assist: extract_function
//
-// Extracts selected statements into new function.
+// Extracts selected statements and comments into new function.
//
// ```
// fn main() {
// let n = 1;
// $0let m = n + 2;
+// // calculate
// let k = m + n;$0
// let g = 3;
// }
//
// fn $0fun_name(n: i32) {
// let m = n + 2;
+// // calculate
// let k = m + n;
// }
// ```
syntax::NodeOrToken::Node(n) => n,
syntax::NodeOrToken::Token(t) => t.parent()?,
};
+
let body = extraction_target(&node, range)?;
let container_info = body.analyze_container(&ctx.sema)?;
}
fn from_range(parent: ast::StmtList, selected: TextRange) -> FunctionBody {
- let mut text_range = parent
- .statements()
- .map(|stmt| stmt.syntax().text_range())
- .filter(|&stmt| selected.intersect(stmt).filter(|it| !it.is_empty()).is_some())
+ let full_body = parent.syntax().children_with_tokens();
+
+ let mut text_range = full_body
+ .filter(|it| ast::Stmt::can_cast(it.kind()) || it.kind() == COMMENT)
+ .map(|element| element.text_range())
+ .filter(|&range| selected.intersect(range).filter(|it| !it.is_empty()).is_some())
.reduce(|acc, stmt| acc.cover(stmt));
+
if let Some(tail_range) = parent
.tail_expr()
.map(|it| it.syntax().text_range())
// We can move the value into the function call if it's not used after the call,
// if the var is not used but defined outside a loop we are extracting from we can't move it either
// as the function will reuse it in the next iteration.
- let move_local = !has_usages && defined_outside_parent_loop;
+ let move_local = (!has_usages && defined_outside_parent_loop) || ty.is_reference();
Param { var, ty, move_local, requires_mut, is_copy }
})
.collect()
let stmt = make::expr_stmt(action);
let block = make::block_expr(iter::once(stmt.into()), None);
let controlflow_break_path = make::path_from_text("ControlFlow::Break");
- let condition = make::condition(
+ let condition = make::expr_let(
+ make::tuple_struct_pat(
+ controlflow_break_path,
+ iter::once(make::wildcard_pat().into()),
+ )
+ .into(),
call_expr,
- Some(
- make::tuple_struct_pat(
- controlflow_break_path,
- iter::once(make::wildcard_pat().into()),
- )
- .into(),
- ),
);
- make::expr_if(condition, block, None)
+ make::expr_if(condition.into(), block, None)
}
FlowHandler::IfOption { action } => {
let path = make::ext::ident_path("Some");
let value_pat = make::ext::simple_ident_pat(make::name("value"));
let pattern = make::tuple_struct_pat(path, iter::once(value_pat.into()));
- let cond = make::condition(call_expr, Some(pattern.into()));
+ let cond = make::expr_let(pattern.into(), call_expr);
let value = make::expr_path(make::ext::ident_path("value"));
let action_expr = action.make_result_handler(Some(value));
let action_stmt = make::expr_stmt(action_expr);
let then = make::block_expr(iter::once(action_stmt.into()), None);
- make::expr_if(cond, then, None)
+ make::expr_if(cond.into(), then, None)
}
FlowHandler::MatchOption { none } => {
let some_name = "value";
} else {
FlowHandler::from_ret_ty(fun, &ret_ty)
};
+
let block = match &fun.body {
FunctionBody::Expr(expr) => {
let expr = rewrite_body_segment(ctx, &fun.params, &handler, expr.syntax());
FunctionBody::Span { parent, text_range } => {
let mut elements: Vec<_> = parent
.syntax()
- .children()
+ .children_with_tokens()
.filter(|it| text_range.contains_range(it.text_range()))
- .map(|it| rewrite_body_segment(ctx, &fun.params, &handler, &it))
+ .map(|it| match &it {
+ syntax::NodeOrToken::Node(n) => syntax::NodeOrToken::Node(
+ rewrite_body_segment(ctx, &fun.params, &handler, &n),
+ ),
+ _ => it,
+ })
.collect();
- let mut tail_expr = match elements.pop() {
- Some(node) => ast::Expr::cast(node.clone()).or_else(|| {
- elements.push(node);
- None
- }),
- None => None,
+ let mut tail_expr = match &elements.last() {
+ Some(syntax::NodeOrToken::Node(node)) if ast::Expr::can_cast(node.kind()) => {
+ ast::Expr::cast(node.clone())
+ }
+ _ => None,
};
- if tail_expr.is_none() {
- match fun.outliving_locals.as_slice() {
+ match tail_expr {
+ Some(_) => {
+ elements.pop();
+ }
+ None => match fun.outliving_locals.as_slice() {
[] => {}
[var] => {
tail_expr = Some(path_expr_from_local(ctx, var.local));
let expr = make::expr_tuple(exprs);
tail_expr = Some(expr);
}
- }
- }
-
- let elements = elements.into_iter().filter_map(|node| match ast::Stmt::cast(node) {
- Some(stmt) => Some(stmt),
- None => {
- stdx::never!("block contains non-statement");
- None
- }
- });
+ },
+ };
let body_indent = IndentLevel(1);
- let elements = elements.map(|stmt| stmt.dedent(old_indent).indent(body_indent));
+ let elements = elements
+ .into_iter()
+ .map(|node_or_token| match &node_or_token {
+ syntax::NodeOrToken::Node(node) => match ast::Stmt::cast(node.clone()) {
+ Some(stmt) => {
+ let indented = stmt.dedent(old_indent).indent(body_indent);
+ let ast_node = indented.syntax().clone_subtree();
+ syntax::NodeOrToken::Node(ast_node)
+ }
+ _ => node_or_token,
+ },
+ _ => node_or_token,
+ })
+ .collect::<Vec<SyntaxElement>>();
let tail_expr = tail_expr.map(|expr| expr.dedent(old_indent).indent(body_indent));
- make::block_expr(elements, tail_expr)
+ make::hacky_block_expr_with_comments(elements, tail_expr)
}
};
"#,
r#"
fn foo() {
- /**/
fun_name();
- /**/
}
fn $0fun_name() {
+ /**/
foo();
foo();
+ /**/
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn extract_does_not_tear_body_apart() {
+ check_assist(
+ extract_function,
+ r#"
+fn foo() {
+ $0foo();
+}$0
+"#,
+ r#"
+fn foo() {
+ fun_name();
+}
+
+fn $0fun_name() {
+ foo();
}
"#,
);
fn $0fun_name(a: _) -> _ {
a
}
+"#,
+ );
+ }
+
+ #[test]
+ fn reference_mutable_param_with_further_usages() {
+ check_assist(
+ extract_function,
+ r#"
+pub struct Foo {
+ field: u32,
+}
+
+pub fn testfn(arg: &mut Foo) {
+ $0arg.field = 8;$0
+ // Simulating access after the extracted portion
+ arg.field = 16;
+}
+"#,
+ r#"
+pub struct Foo {
+ field: u32,
+}
+
+pub fn testfn(arg: &mut Foo) {
+ fun_name(arg);
+ // Simulating access after the extracted portion
+ arg.field = 16;
+}
+
+fn $0fun_name(arg: &mut Foo) {
+ arg.field = 8;
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn reference_mutable_param_without_further_usages() {
+ check_assist(
+ extract_function,
+ r#"
+pub struct Foo {
+ field: u32,
+}
+
+pub fn testfn(arg: &mut Foo) {
+ $0arg.field = 8;$0
+}
+"#,
+ r#"
+pub struct Foo {
+ field: u32,
+}
+
+pub fn testfn(arg: &mut Foo) {
+ fun_name(arg);
+}
+
+fn $0fun_name(arg: &mut Foo) {
+ arg.field = 8;
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn extract_function_copies_comment_at_start() {
+ check_assist(
+ extract_function,
+ r#"
+fn func() {
+ let i = 0;
+ $0// comment here!
+ let x = 0;$0
+}
+"#,
+ r#"
+fn func() {
+ let i = 0;
+ fun_name();
+}
+
+fn $0fun_name() {
+ // comment here!
+ let x = 0;
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn extract_function_copies_comment_in_between() {
+ check_assist(
+ extract_function,
+ r#"
+fn func() {
+ let i = 0;$0
+ let a = 0;
+ // comment here!
+ let x = 0;$0
+}
+"#,
+ r#"
+fn func() {
+ let i = 0;
+ fun_name();
+}
+
+fn $0fun_name() {
+ let a = 0;
+ // comment here!
+ let x = 0;
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn extract_function_copies_comment_at_end() {
+ check_assist(
+ extract_function,
+ r#"
+fn func() {
+ let i = 0;
+ $0let x = 0;
+ // comment here!$0
+}
+"#,
+ r#"
+fn func() {
+ let i = 0;
+ fun_name();
+}
+
+fn $0fun_name() {
+ let x = 0;
+ // comment here!
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn extract_function_copies_comment_indented() {
+ check_assist(
+ extract_function,
+ r#"
+fn func() {
+ let i = 0;
+ $0let x = 0;
+ while(true) {
+ // comment here!
+ }$0
+}
+"#,
+ r#"
+fn func() {
+ let i = 0;
+ fun_name();
+}
+
+fn $0fun_name() {
+ let x = 0;
+ while(true) {
+ // comment here!
+ }
+}
+"#,
+ );
+ }
+
+ // FIXME: we do want to preserve whitespace
+ #[test]
+ fn extract_function_does_not_preserve_whitespace() {
+ check_assist(
+ extract_function,
+ r#"
+fn func() {
+ let i = 0;
+ $0let a = 0;
+
+ let x = 0;$0
+}
+"#,
+ r#"
+fn func() {
+ let i = 0;
+ fun_name();
+}
+
+fn $0fun_name() {
+ let a = 0;
+ let x = 0;
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn extract_function_long_form_comment() {
+ check_assist(
+ extract_function,
+ r#"
+fn func() {
+ let i = 0;
+ $0/* a comment */
+ let x = 0;$0
+}
+"#,
+ r#"
+fn func() {
+ let i = 0;
+ fun_name();
+}
+
+fn $0fun_name() {
+ /* a comment */
+ let x = 0;
+}
"#,
);
}