1 files changed, 71 insertions, 1 deletions

diff --git a/crates/ra_ide/src/completion/completion_item.rs b/crates/ra_ide/src/completion/completion_item.rs
index bc0f1aff5..a3ae9c86b 100644
--- a/crates/ra_ide/src/completion/completion_item.rs
+++ b/crates/ra_ide/src/completion/completion_item.rs
@@ -2,7 +2,9 @@
 
 use std::fmt;
 
-use hir::Documentation;
+use super::completion_context::CompletionContext;
+use crate::call_info::call_info;
+use hir::{Documentation, HirDisplay};
 use ra_syntax::TextRange;
 use ra_text_edit::TextEdit;
 
@@ -51,6 +53,9 @@ pub struct CompletionItem {
     /// If completing a function call, ask the editor to show parameter popup
     /// after completion.
     trigger_call_info: bool,
+
+    /// Score is usefull to pre select or display in better order completion items
+    score: Option<CompletionScore>,
 }
 
 // We use custom debug for CompletionItem to make `insta`'s diffs more readable.
@@ -80,6 +85,9 @@ impl fmt::Debug for CompletionItem {
         if self.deprecated {
             s.field("deprecated", &true);
         }
+        if let Some(score) = &self.score {
+            s.field("score", score);
+        }
         if self.trigger_call_info {
             s.field("trigger_call_info", &true);
         }
@@ -147,6 +155,7 @@ impl CompletionItem {
             text_edit: None,
             deprecated: None,
             trigger_call_info: None,
+            score: None,
         }
     }
     /// What user sees in pop-up in the UI.
@@ -186,6 +195,14 @@ impl CompletionItem {
         self.deprecated
     }
 
+    pub fn score(&self) -> Option<CompletionScore> {
+        self.score.clone()
+    }
+
+    pub fn set_score(&mut self, score: CompletionScore) {
+        self.score = Some(score);
+    }
+
     pub fn trigger_call_info(&self) -> bool {
         self.trigger_call_info
     }
@@ -206,6 +223,7 @@ pub(crate) struct Builder {
     text_edit: Option<TextEdit>,
     deprecated: Option<bool>,
     trigger_call_info: Option<bool>,
+    score: Option<CompletionScore>,
 }
 
 impl Builder {
@@ -235,6 +253,7 @@ impl Builder {
             completion_kind: self.completion_kind,
             deprecated: self.deprecated.unwrap_or(false),
             trigger_call_info: self.trigger_call_info.unwrap_or(false),
+            score: self.score,
         }
     }
     pub(crate) fn lookup_by(mut self, lookup: impl Into<String>) -> Builder {
@@ -285,6 +304,51 @@ impl Builder {
         self.deprecated = Some(deprecated);
         self
     }
+    #[allow(unused)]
+    pub(crate) fn compute_score(mut self, ctx: &CompletionContext) -> Builder {
+        let (active_name, active_type) = if let Some(record_field) = &ctx.record_field_syntax {
+            if let Some((struct_field, _)) = ctx.sema.resolve_record_field(record_field) {
+                (
+                    struct_field.name(ctx.db).to_string(),
+                    struct_field.signature_ty(ctx.db).display(ctx.db).to_string(),
+                )
+            } else {
+                return self;
+            }
+        } else if let Some(call_info) = call_info(ctx.db, ctx.file_position) {
+            if call_info.active_parameter_type().is_some()
+                && call_info.active_parameter_name().is_some()
+            {
+                (
+                    call_info.active_parameter_name().unwrap(),
+                    call_info.active_parameter_type().unwrap(),
+                )
+            } else {
+                return self;
+            }
+        } else {
+            return self;
+        };
+
+        // Compute score
+        // For the same type
+        if let Some(a_parameter_type) = &self.detail {
+            if &active_type == a_parameter_type {
+                // If same type + same name then go top position
+                if active_name == self.label {
+                    return self.set_score(CompletionScore::TypeAndNameMatch);
+                } else {
+                    return self.set_score(CompletionScore::TypeMatch);
+                }
+            }
+        }
+
+        self
+    }
+    pub(crate) fn set_score(mut self, score: CompletionScore) -> Builder {
+        self.score = Some(score);
+        self
+    }
     pub(crate) fn trigger_call_info(mut self) -> Builder {
         self.trigger_call_info = Some(true);
         self
@@ -297,6 +361,12 @@ impl<'a> Into<CompletionItem> for Builder {
     }
 }
 
+#[derive(Debug, Clone)]
+pub enum CompletionScore {
+    TypeMatch,
+    TypeAndNameMatch,
+}
+
 /// Represents an in-progress set of completions being built.
 #[derive(Debug, Default)]
 pub(crate) struct Completions {