Make add_label_to_loop basically work

Author: xffxff

crates/ide-assists/src/handlers/add_label_to_loop.rs

@@ -0,0 +1,93 @@
+use ide_db::syntax_helpers::node_ext::for_each_break_and_continue_expr;
+use syntax::ast::{self, AstNode, HasLoopBody};
+use syntax::T;
+
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+
+// Assist: add_lifetime_to_type
+//
+// Adds a new lifetime to a struct, enum or union.
+//
+// ```
+// struct Point {
+//     x: &u32,
+//     y: u32,
+// }
+// ```
+// ->
+// ```
+// struct Point<'a> {
+//     x: &'a u32,
+//     y: u32,
+// }
+// ```
+pub(crate) fn add_label_to_loop(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+    let loop_expr = ctx.find_node_at_offset::<ast::LoopExpr>()?;
+    let loop_body = loop_expr.loop_body().and_then(|it| it.stmt_list());
+    let mut related_exprs = vec![];
+    related_exprs.push(ast::Expr::LoopExpr(loop_expr.clone()));
+    for_each_break_and_continue_expr(loop_expr.label(), loop_body, &mut |expr| {
+        if let ast::Expr::BreakExpr(_) | ast::Expr::ContinueExpr(_) = expr {
+            related_exprs.push(expr)
+        }
+    });
+    dbg!(loop_expr.syntax().text_range());
+
+    acc.add(
+        AssistId("add_label_to_loop", AssistKind::Generate),
+        "Add Label",
+        loop_expr.syntax().text_range(),
+        |builder| {
+            for expr in related_exprs {
+                match expr {
+                    ast::Expr::BreakExpr(break_expr) => {
+                        if let Some(break_token) = break_expr.break_token() {
+                            builder.insert(break_token.text_range().end(), " 'loop")
+                        }
+                    },
+                    ast::Expr::ContinueExpr(continue_expr) => {
+                        if let Some(continue_token) = continue_expr.continue_token() {
+                            builder.insert(continue_token.text_range().end(), " 'loop")
+                        }
+                    },
+                    ast::Expr::LoopExpr(loop_expr) => {
+                        if let Some(loop_token) = loop_expr.loop_token() {
+                            builder.insert(loop_token.text_range().start(), "'loop: ")
+                        }
+                    },
+                    _ => todo!()
+                }
+            }
+        },
+    )
+}
+
+
+#[cfg(test)]
+mod tests {
+    use crate::tests::check_assist;
+
+    use super::*;
+
+    #[test]
+    fn add_label() {
+        check_assist(
+            add_label_to_loop,
+            r#"
+fn main() {
+    loop$0 { 
+        break; 
+        continue; 
+    }
+}"#,
+            r#"
+fn main() {
+    'loop: loop { 
+        break 'loop; 
+        continue 'loop; 
+    }
+}"#,
+        );
+    }
+
+}

crates/ide-assists/src/lib.rs

@@ -104,6 +104,7 @@ mod handlers {
     pub(crate) type Handler = fn(&mut Assists, &AssistContext) -> Option<()>;
 
     mod add_explicit_type;
+    mod add_label_to_loop;
     mod add_lifetime_to_type;
     mod add_missing_impl_members;
     mod add_turbo_fish;
@@ -193,6 +194,7 @@ mod handlers {
         &[
             // These are alphabetic for the foolish consistency
             add_explicit_type::add_explicit_type,
+            add_label_to_loop::add_label_to_loop,
             add_missing_match_arms::add_missing_match_arms,
             add_lifetime_to_type::add_lifetime_to_type,
             add_return_type::add_return_type,