1 files changed, 51 insertions, 73 deletions

diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index f4f37614f..b6dc7cb1b 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -10,7 +10,7 @@ macro_rules! eprintln {
     ($($tt:tt)*) => { stdx::eprintln!($($tt)*) };
 }
 
-mod assist_ctx;
+mod assist_context;
 mod marks;
 #[cfg(test)]
 mod tests;
@@ -18,20 +18,22 @@ pub mod utils;
 pub mod ast_transform;
 
 use hir::Semantics;
-use ra_db::{FileId, FileRange};
-use ra_ide_db::RootDatabase;
-use ra_syntax::{TextRange, TextSize};
-use ra_text_edit::TextEdit;
+use ra_db::FileRange;
+use ra_ide_db::{source_change::SourceChange, RootDatabase};
+use ra_syntax::TextRange;
 
-pub(crate) use crate::assist_ctx::{Assist, AssistCtx};
+pub(crate) use crate::assist_context::{AssistContext, Assists};
 
 /// Unique identifier of the assist, should not be shown to the user
 /// directly.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct AssistId(pub &'static str);
 
+#[derive(Clone, Debug)]
+pub struct GroupLabel(pub String);
+
 #[derive(Debug, Clone)]
-pub struct AssistLabel {
+pub struct Assist {
     pub id: AssistId,
     /// Short description of the assist, as shown in the UI.
     pub label: String,
@@ -41,93 +43,69 @@ pub struct AssistLabel {
     pub target: TextRange,
 }
 
-#[derive(Clone, Debug)]
-pub struct GroupLabel(pub String);
+#[derive(Debug, Clone)]
+pub struct ResolvedAssist {
+    pub assist: Assist,
+    pub source_change: SourceChange,
+}
+
+impl Assist {
+    /// Return all the assists applicable at the given position.
+    ///
+    /// Assists are returned in the "unresolved" state, that is only labels are
+    /// returned, without actual edits.
+    pub fn unresolved(db: &RootDatabase, range: FileRange) -> Vec<Assist> {
+        let sema = Semantics::new(db);
+        let ctx = AssistContext::new(sema, range);
+        let mut acc = Assists::new_unresolved(&ctx);
+        handlers::all().iter().for_each(|handler| {
+            handler(&mut acc, &ctx);
+        });
+        acc.finish_unresolved()
+    }
+
+    /// Return all the assists applicable at the given position.
+    ///
+    /// Assists are returned in the "resolved" state, that is with edit fully
+    /// computed.
+    pub fn resolved(db: &RootDatabase, range: FileRange) -> Vec<ResolvedAssist> {
+        let sema = Semantics::new(db);
+        let ctx = AssistContext::new(sema, range);
+        let mut acc = Assists::new_resolved(&ctx);
+        handlers::all().iter().for_each(|handler| {
+            handler(&mut acc, &ctx);
+        });
+        acc.finish_resolved()
+    }
 
-impl AssistLabel {
     pub(crate) fn new(
         id: AssistId,
         label: String,
         group: Option<GroupLabel>,
         target: TextRange,
-    ) -> AssistLabel {
+    ) -> Assist {
         // FIXME: make fields private, so that this invariant can't be broken
         assert!(label.starts_with(|c: char| c.is_uppercase()));
-        AssistLabel { id, label, group, target }
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct AssistAction {
-    pub edit: TextEdit,
-    pub cursor_position: Option<TextSize>,
-    pub file: AssistFile,
-}
-
-#[derive(Debug, Clone)]
-pub struct ResolvedAssist {
-    pub label: AssistLabel,
-    pub action: AssistAction,
-}
-
-#[derive(Debug, Clone, Copy)]
-pub enum AssistFile {
-    CurrentFile,
-    TargetFile(FileId),
-}
-
-impl Default for AssistFile {
-    fn default() -> Self {
-        Self::CurrentFile
+        Assist { id, label, group, target }
     }
 }
 
-/// Return all the assists applicable at the given position.
-///
-/// Assists are returned in the "unresolved" state, that is only labels are
-/// returned, without actual edits.
-pub fn unresolved_assists(db: &RootDatabase, range: FileRange) -> Vec<AssistLabel> {
-    let sema = Semantics::new(db);
-    let ctx = AssistCtx::new(&sema, range, false);
-    handlers::all()
-        .iter()
-        .filter_map(|f| f(ctx.clone()))
-        .flat_map(|it| it.0)
-        .map(|a| a.label)
-        .collect()
-}
-
-/// Return all the assists applicable at the given position.
-///
-/// Assists are returned in the "resolved" state, that is with edit fully
-/// computed.
-pub fn resolved_assists(db: &RootDatabase, range: FileRange) -> Vec<ResolvedAssist> {
-    let sema = Semantics::new(db);
-    let ctx = AssistCtx::new(&sema, range, true);
-    let mut a = handlers::all()
-        .iter()
-        .filter_map(|f| f(ctx.clone()))
-        .flat_map(|it| it.0)
-        .map(|it| it.into_resolved().unwrap())
-        .collect::<Vec<_>>();
-    a.sort_by_key(|it| it.label.target.len());
-    a
-}
-
 mod handlers {
-    use crate::{Assist, AssistCtx};
+    use crate::{AssistContext, Assists};
 
-    pub(crate) type Handler = fn(AssistCtx) -> Option<Assist>;
+    pub(crate) type Handler = fn(&mut Assists, &AssistContext) -> Option<()>;
 
     mod add_custom_impl;
     mod add_derive;
     mod add_explicit_type;
+    mod add_from_impl_for_enum;
     mod add_function;
     mod add_impl;
     mod add_missing_impl_members;
     mod add_new;
     mod apply_demorgan;
     mod auto_import;
+    mod change_return_type_to_result;
     mod change_visibility;
     mod early_return;
     mod fill_match_arms;
@@ -144,13 +122,12 @@ mod handlers {
     mod raw_string;
     mod remove_dbg;
     mod remove_mut;
+    mod reorder_fields;
     mod replace_if_let_with_match;
     mod replace_let_with_if_let;
     mod replace_qualified_name_with_use;
     mod replace_unwrap_with_match;
     mod split_import;
-    mod add_from_impl_for_enum;
-    mod reorder_fields;
     mod unwrap_block;
 
     pub(crate) fn all() -> &'static [Handler] {
@@ -165,6 +142,7 @@ mod handlers {
             add_new::add_new,
             apply_demorgan::apply_demorgan,
             auto_import::auto_import,
+            change_return_type_to_result::change_return_type_to_result,
             change_visibility::change_visibility,
             early_return::convert_to_guarded_return,
             fill_match_arms::fill_match_arms,