Auto merge of rust-lang#13986 - MariaSolOs:limit-completions, r=Veykril

Add setting for limiting number of completions

For rust-lang#13911.

Author: bors

crates/ide-completion/src/config.rs

@@ -19,6 +19,7 @@ pub struct CompletionConfig {
     pub insert_use: InsertUseConfig,
     pub prefer_no_std: bool,
     pub snippets: Vec<Snippet>,
+    pub limit: Option<usize>,
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]

crates/ide-completion/src/tests.rs

@@ -75,6 +75,7 @@ pub(crate) const TEST_CONFIG: CompletionConfig = CompletionConfig {
         skip_glob_imports: true,
     },
     snippets: Vec::new(),
+    limit: None,
 };
 
 pub(crate) fn completion_list(ra_fixture: &str) -> String {

crates/rust-analyzer/src/config.rs

@@ -200,6 +200,8 @@ config_data! {
         completion_autoself_enable: bool        = "true",
         /// Whether to add parenthesis and argument snippets when completing function.
         completion_callable_snippets: CallableCompletionDef  = "\"fill_arguments\"",
+        /// Maximum number of completions to return. If `None`, the limit is infinite.
+        completion_limit: Option<usize> = "null",
         /// Whether to show postfix snippets like `dbg`, `if`, `not`, etc.
         completion_postfix_enable: bool         = "true",
         /// Enables completions of private items and fields that are defined in the current workspace even if they are not visible at the current position.
@@ -1343,6 +1345,7 @@ impl Config {
                     .snippet_support?
             )),
             snippets: self.snippets.clone(),
+            limit: self.data.completion_limit,
         }
     }
 

crates/rust-analyzer/src/integrated_benchmarks.rs

@@ -146,6 +146,7 @@ fn integrated_completion_benchmark() {
             },
             snippets: Vec::new(),
             prefer_no_std: false,
+            limit: None,
         };
         let position =
             FilePosition { file_id, offset: TextSize::try_from(completion_offset).unwrap() };
@@ -184,6 +185,7 @@ fn integrated_completion_benchmark() {
             },
             snippets: Vec::new(),
             prefer_no_std: false,
+            limit: None,
         };
         let position =
             FilePosition { file_id, offset: TextSize::try_from(completion_offset).unwrap() };

crates/rust-analyzer/src/to_proto.rs

@@ -215,8 +215,14 @@ pub(crate) fn completion_items(
     let max_relevance = items.iter().map(|it| it.relevance().score()).max().unwrap_or_default();
     let mut res = Vec::with_capacity(items.len());
     for item in items {
-        completion_item(&mut res, config, line_index, &tdpp, max_relevance, item)
+        completion_item(&mut res, config, line_index, &tdpp, max_relevance, item);
     }
+
+    if let Some(limit) = config.completion().limit {
+        res.sort_by(|item1, item2| item1.sort_text.cmp(&item2.sort_text));
+        res.truncate(limit);
+    }
+
     res
 }
 

docs/user/generated_config.adoc

@@ -227,6 +227,11 @@ with `self` prefixed to them when inside a method.
 --
 Whether to add parenthesis and argument snippets when completing function.
 --
+[[rust-analyzer.completion.limit]]rust-analyzer.completion.limit (default: `null`)::
++
+--
+Maximum number of completions to return. If `None`, the limit is infinite.
+--
 [[rust-analyzer.completion.postfix.enable]]rust-analyzer.completion.postfix.enable (default: `true`)::
 +
 --

editors/code/package.json

@@ -705,6 +705,15 @@
                         "Do no snippet completions for callables."
                     ]
                 },
+                "rust-analyzer.completion.limit": {
+                    "markdownDescription": "Maximum number of completions to return. If `None`, the limit is infinite.",
+                    "default": null,
+                    "type": [
+                        "null",
+                        "integer"
+                    ],
+                    "minimum": 0
+                },
                 "rust-analyzer.completion.postfix.enable": {
                     "markdownDescription": "Whether to show postfix snippets like `dbg`, `if`, `not`, etc.",
                     "default": true,