bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide-assists/src/handlers/add_label_to_loop.rs')
-rw-r--r--crates/ide-assists/src/handlers/add_label_to_loop.rs164
1 files changed, 164 insertions, 0 deletions
diff --git a/crates/ide-assists/src/handlers/add_label_to_loop.rs b/crates/ide-assists/src/handlers/add_label_to_loop.rs
new file mode 100644
index 0000000000..a14cc45989
--- /dev/null
+++ b/crates/ide-assists/src/handlers/add_label_to_loop.rs
@@ -0,0 +1,164 @@
+use ide_db::syntax_helpers::node_ext::for_each_break_and_continue_expr;
+use syntax::{
+ ast::{self, AstNode, HasLoopBody},
+ T,
+};
+
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+
+// Assist: add_label_to_loop
+//
+// Adds a label to a loop.
+//
+// ```
+// fn main() {
+// loop$0 {
+// break;
+// continue;
+// }
+// }
+// ```
+// ->
+// ```
+// fn main() {
+// 'l: loop {
+// break 'l;
+// continue 'l;
+// }
+// }
+// ```
+pub(crate) fn add_label_to_loop(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+ let loop_kw = ctx.find_token_syntax_at_offset(T![loop])?;
+ let loop_expr = loop_kw.parent().and_then(ast::LoopExpr::cast)?;
+ if loop_expr.label().is_some() {
+ return None;
+ }
+
+ acc.add(
+ AssistId("add_label_to_loop", AssistKind::Generate),
+ "Add Label",
+ loop_expr.syntax().text_range(),
+ |builder| {
+ builder.insert(loop_kw.text_range().start(), "'l: ");
+
+ let loop_body = loop_expr.loop_body().and_then(|it| it.stmt_list());
+ for_each_break_and_continue_expr(
+ loop_expr.label(),
+ loop_body,
+ &mut |expr| match expr {
+ ast::Expr::BreakExpr(break_expr) => {
+ if let Some(break_token) = break_expr.break_token() {
+ builder.insert(break_token.text_range().end(), " 'l")
+ }
+ }
+ ast::Expr::ContinueExpr(continue_expr) => {
+ if let Some(continue_token) = continue_expr.continue_token() {
+ builder.insert(continue_token.text_range().end(), " 'l")
+ }
+ }
+ _ => {}
+ },
+ );
+ },
+ )
+}
+
+#[cfg(test)]
+mod tests {
+ use crate::tests::{check_assist, check_assist_not_applicable};
+
+ use super::*;
+
+ #[test]
+ fn add_label() {
+ check_assist(
+ add_label_to_loop,
+ r#"
+fn main() {
+ loop$0 {
+ break;
+ continue;
+ }
+}"#,
+ r#"
+fn main() {
+ 'l: loop {
+ break 'l;
+ continue 'l;
+ }
+}"#,
+ );
+ }
+
+ #[test]
+ fn add_label_to_outer_loop() {
+ check_assist(
+ add_label_to_loop,
+ r#"
+fn main() {
+ loop$0 {
+ break;
+ continue;
+ loop {
+ break;
+ continue;
+ }
+ }
+}"#,
+ r#"
+fn main() {
+ 'l: loop {
+ break 'l;
+ continue 'l;
+ loop {
+ break;
+ continue;
+ }
+ }
+}"#,
+ );
+ }
+
+ #[test]
+ fn add_label_to_inner_loop() {
+ check_assist(
+ add_label_to_loop,
+ r#"
+fn main() {
+ loop {
+ break;
+ continue;
+ loop$0 {
+ break;
+ continue;
+ }
+ }
+}"#,
+ r#"
+fn main() {
+ loop {
+ break;
+ continue;
+ 'l: loop {
+ break 'l;
+ continue 'l;
+ }
+ }
+}"#,
+ );
+ }
+
+ #[test]
+ fn do_not_add_label_if_exists() {
+ check_assist_not_applicable(
+ add_label_to_loop,
+ r#"
+fn main() {
+ 'l: loop$0 {
+ break 'l;
+ continue 'l;
+ }
+}"#,
+ );
+ }
+}