Simplify Assists interface

Instead of building a physical tree structure, just "tag" related
assists with the same group

3 files changed, 54 insertions, 95 deletions

diff --git a/crates/ra_assists/src/assist_ctx.rs b/crates/ra_assists/src/assist_ctx.rs
index 5924a3fd5..5aab5fb8b 100644
--- a/crates/ra_assists/src/assist_ctx.rs
+++ b/crates/ra_assists/src/assist_ctx.rs
@@ -1,5 +1,4 @@
 //! This module defines `AssistCtx` -- the API surface that is exposed to assists.
-use either::Either;
 use hir::{InFile, SourceAnalyzer, SourceBinder};
 use ra_db::{FileRange, SourceDatabase};
 use ra_fmt::{leading_indent, reindent};
@@ -11,12 +10,36 @@ use ra_syntax::{
 };
 use ra_text_edit::TextEditBuilder;
 
-use crate::{AssistAction, AssistId, AssistLabel, ResolvedAssist};
+use crate::{AssistAction, AssistId, AssistLabel, GroupLabel, ResolvedAssist};
 
 #[derive(Clone, Debug)]
-pub(crate) enum Assist {
-    Unresolved { label: AssistLabel },
-    Resolved { assist: ResolvedAssist },
+pub(crate) struct Assist(pub(crate) Vec<AssistInfo>);
+
+#[derive(Clone, Debug)]
+pub(crate) struct AssistInfo {
+    pub(crate) label: AssistLabel,
+    pub(crate) group_label: Option<GroupLabel>,
+    pub(crate) action: Option<AssistAction>,
+}
+
+impl AssistInfo {
+    fn new(label: AssistLabel) -> AssistInfo {
+        AssistInfo { label, group_label: None, action: None }
+    }
+
+    fn resolved(self, action: AssistAction) -> AssistInfo {
+        AssistInfo { action: Some(action), ..self }
+    }
+
+    fn with_group(self, group_label: GroupLabel) -> AssistInfo {
+        AssistInfo { group_label: Some(group_label), ..self }
+    }
+
+    pub(crate) fn into_resolved(self) -> Option<ResolvedAssist> {
+        let label = self.label;
+        let group_label = self.group_label;
+        self.action.map(|action| ResolvedAssist { label, group_label, action })
+    }
 }
 
 pub(crate) type AssistHandler = fn(AssistCtx) -> Option<Assist>;
@@ -84,18 +107,17 @@ impl<'a> AssistCtx<'a> {
     ) -> Option<Assist> {
         let label = AssistLabel::new(label.into(), id);
 
-        let assist = if self.should_compute_edit {
+        let mut info = AssistInfo::new(label);
+        if self.should_compute_edit {
             let action = {
                 let mut edit = ActionBuilder::default();
                 f(&mut edit);
                 edit.build()
             };
-            Assist::Resolved { assist: ResolvedAssist { label, action_data: Either::Left(action) } }
-        } else {
-            Assist::Unresolved { label }
+            info = info.resolved(action)
         };
 
-        Some(assist)
+        Some(Assist(vec![info]))
     }
 
     pub(crate) fn add_assist_group(self, group_name: impl Into<String>) -> AssistGroup<'a> {
@@ -136,7 +158,7 @@ impl<'a> AssistCtx<'a> {
 pub(crate) struct AssistGroup<'a> {
     ctx: AssistCtx<'a>,
     group_name: String,
-    assists: Vec<Assist>,
+    assists: Vec<AssistInfo>,
 }
 
 impl<'a> AssistGroup<'a> {
@@ -148,49 +170,22 @@ impl<'a> AssistGroup<'a> {
     ) {
         let label = AssistLabel::new(label.into(), id);
 
-        let assist = if self.ctx.should_compute_edit {
+        let mut info = AssistInfo::new(label).with_group(GroupLabel(self.group_name.clone()));
+        if self.ctx.should_compute_edit {
             let action = {
                 let mut edit = ActionBuilder::default();
                 f(&mut edit);
                 edit.build()
             };
-            Assist::Resolved { assist: ResolvedAssist { label, action_data: Either::Left(action) } }
-        } else {
-            Assist::Unresolved { label }
+            info = info.resolved(action)
         };
 
-        self.assists.push(assist)
+        self.assists.push(info)
     }
 
     pub(crate) fn finish(self) -> Option<Assist> {
         assert!(!self.assists.is_empty());
-        let mut label = match &self.assists[0] {
-            Assist::Unresolved { label } => label.clone(),
-            Assist::Resolved { assist } => assist.label.clone(),
-        };
-        label.label = self.group_name;
-        let assist = if self.ctx.should_compute_edit {
-            Assist::Resolved {
-                assist: ResolvedAssist {
-                    label,
-                    action_data: Either::Right(
-                        self.assists
-                            .into_iter()
-                            .map(|assist| match assist {
-                                Assist::Resolved {
-                                    assist:
-                                        ResolvedAssist { label: _, action_data: Either::Left(it) },
-                                } => it,
-                                _ => unreachable!(),
-                            })
-                            .collect(),
-                    ),
-                },
-            }
-        } else {
-            Assist::Unresolved { label }
-        };
-        Some(assist)
+        Some(Assist(self.assists))
     }
 }
 
@@ -199,7 +194,6 @@ pub(crate) struct ActionBuilder {
     edit: TextEditBuilder,
     cursor_position: Option<TextUnit>,
     target: Option<TextRange>,
-    label: Option<String>,
 }
 
 impl ActionBuilder {
@@ -261,7 +255,6 @@ impl ActionBuilder {
             edit: self.edit.finish(),
             cursor_position: self.cursor_position,
             target: self.target,
-            label: self.label,
         }
     }
 }
diff --git a/crates/ra_assists/src/doc_tests.rs b/crates/ra_assists/src/doc_tests.rs
index ae0e5605c..c0f9bc1fb 100644
--- a/crates/ra_assists/src/doc_tests.rs
+++ b/crates/ra_assists/src/doc_tests.rs
@@ -30,6 +30,6 @@ fn check(assist_id: &str, before: &str, after: &str) {
             )
         });
 
-    let actual = assist.get_first_action().edit.apply(&before);
+    let actual = assist.action.edit.apply(&before);
     assert_eq_text!(after, &actual);
 }
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index f79189ae8..828a8e9e8 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -12,9 +12,6 @@ mod doc_tests;
 mod utils;
 pub mod ast_transform;
 
-use std::cmp::Ordering;
-
-use either::Either;
 use ra_db::FileRange;
 use ra_ide_db::RootDatabase;
 use ra_syntax::{TextRange, TextUnit};
@@ -35,6 +32,9 @@ pub struct AssistLabel {
     pub id: AssistId,
 }
 
+#[derive(Clone, Debug)]
+pub struct GroupLabel(pub String);
+
 impl AssistLabel {
     pub(crate) fn new(label: String, id: AssistId) -> AssistLabel {
         // FIXME: make fields private, so that this invariant can't be broken
@@ -45,7 +45,6 @@ impl AssistLabel {
 
 #[derive(Debug, Clone)]
 pub struct AssistAction {
-    pub label: Option<String>,
     pub edit: TextEdit,
     pub cursor_position: Option<TextUnit>,
     // FIXME: This belongs to `AssistLabel`
@@ -55,16 +54,8 @@ pub struct AssistAction {
 #[derive(Debug, Clone)]
 pub struct ResolvedAssist {
     pub label: AssistLabel,
-    pub action_data: Either<AssistAction, Vec<AssistAction>>,
-}
-
-impl ResolvedAssist {
-    pub fn get_first_action(&self) -> AssistAction {
-        match &self.action_data {
-            Either::Left(action) => action.clone(),
-            Either::Right(actions) => actions[0].clone(),
-        }
-    }
+    pub group_label: Option<GroupLabel>,
+    pub action: AssistAction,
 }
 
 /// Return all the assists applicable at the given position.
@@ -76,10 +67,8 @@ pub fn unresolved_assists(db: &RootDatabase, range: FileRange) -> Vec<AssistLabe
     handlers::all()
         .iter()
         .filter_map(|f| f(ctx.clone()))
-        .map(|a| match a {
-            Assist::Unresolved { label } => label,
-            Assist::Resolved { .. } => unreachable!(),
-        })
+        .flat_map(|it| it.0)
+        .map(|a| a.label)
         .collect()
 }
 
@@ -92,24 +81,13 @@ pub fn resolved_assists(db: &RootDatabase, range: FileRange) -> Vec<ResolvedAssi
     let mut a = handlers::all()
         .iter()
         .filter_map(|f| f(ctx.clone()))
-        .map(|a| match a {
-            Assist::Resolved { assist } => assist,
-            Assist::Unresolved { .. } => unreachable!(),
-        })
+        .flat_map(|it| it.0)
+        .map(|it| it.into_resolved().unwrap())
         .collect::<Vec<_>>();
-    sort_assists(&mut a);
+    a.sort_by_key(|it| it.action.target.map_or(TextUnit::from(!0u32), |it| it.len()));
     a
 }
 
-fn sort_assists(assists: &mut [ResolvedAssist]) {
-    assists.sort_by(|a, b| match (a.get_first_action().target, b.get_first_action().target) {
-        (Some(a), Some(b)) => a.len().cmp(&b.len()),
-        (Some(_), None) => Ordering::Less,
-        (None, Some(_)) => Ordering::Greater,
-        (None, None) => Ordering::Equal,
-    });
-}
-
 mod handlers {
     use crate::AssistHandler;
 
@@ -184,7 +162,7 @@ mod helpers {
     use ra_syntax::TextRange;
     use test_utils::{add_cursor, assert_eq_text, extract_offset, extract_range};
 
-    use crate::{Assist, AssistCtx, AssistHandler};
+    use crate::{AssistCtx, AssistHandler};
 
     pub(crate) fn with_single_file(text: &str) -> (RootDatabase, FileId) {
         let (mut db, file_id) = RootDatabase::with_single_file(text);
@@ -202,10 +180,7 @@ mod helpers {
             FileRange { file_id, range: TextRange::offset_len(before_cursor_pos, 0.into()) };
         let assist =
             assist(AssistCtx::new(&db, frange, true)).expect("code action is not applicable");
-        let action = match assist {
-            Assist::Unresolved { .. } => unreachable!(),
-            Assist::Resolved { assist } => assist.get_first_action(),
-        };
+        let action = assist.0[0].action.clone().unwrap();
 
         let actual = action.edit.apply(&before);
         let actual_cursor_pos = match action.cursor_position {
@@ -225,10 +200,7 @@ mod helpers {
         let frange = FileRange { file_id, range };
         let assist =
             assist(AssistCtx::new(&db, frange, true)).expect("code action is not applicable");
-        let action = match assist {
-            Assist::Unresolved { .. } => unreachable!(),
-            Assist::Resolved { assist } => assist.get_first_action(),
-        };
+        let action = assist.0[0].action.clone().unwrap();
 
         let mut actual = action.edit.apply(&before);
         if let Some(pos) = action.cursor_position {
@@ -244,10 +216,7 @@ mod helpers {
             FileRange { file_id, range: TextRange::offset_len(before_cursor_pos, 0.into()) };
         let assist =
             assist(AssistCtx::new(&db, frange, true)).expect("code action is not applicable");
-        let action = match assist {
-            Assist::Unresolved { .. } => unreachable!(),
-            Assist::Resolved { assist } => assist.get_first_action(),
-        };
+        let action = assist.0[0].action.clone().unwrap();
 
         let range = action.target.expect("expected target on action");
         assert_eq_text!(&before[range.start().to_usize()..range.end().to_usize()], target);
@@ -259,10 +228,7 @@ mod helpers {
         let frange = FileRange { file_id, range };
         let assist =
             assist(AssistCtx::new(&db, frange, true)).expect("code action is not applicable");
-        let action = match assist {
-            Assist::Unresolved { .. } => unreachable!(),
-            Assist::Resolved { assist } => assist.get_first_action(),
-        };
+        let action = assist.0[0].action.clone().unwrap();
 
         let range = action.target.expect("expected target on action");
         assert_eq_text!(&before[range.start().to_usize()..range.end().to_usize()], target);