add documentation feature for completions

Author: gerau

src/backend.rs

@@ -169,8 +169,19 @@ impl LanguageServer for Backend {
             }
         }
 
-        let mut completions =
-            CompletionProvider::get_function_completions(document.functions.as_slice());
+        let mut completions = CompletionProvider::get_function_completions(
+            &document
+                .functions
+                .iter()
+                .map(|func| {
+                    let function_doc = document
+                        .functions_docs
+                        .get(&func.name().to_string())
+                        .map_or(String::new(), |s| s.clone());
+                    (func.to_owned(), function_doc)
+                })
+                .collect::<Vec<_>>(),
+        );
         completions.extend_from_slice(self.completion_provider.builtins());
 
         Ok(Some(CompletionResponse::Array(completions)))
@@ -307,13 +318,13 @@ impl Backend {
                 let function = document.functions.iter().find(|f| f.name() == func)?;
                 let function_doc = document.functions_docs.get(&func.to_string())?;
 
-                let template = completion::function_to_template(function);
+                let template = completion::function_to_template(function, &function_doc);
                 let description = format!(
                     "```simplicityhl\nfn {}({}) -> {}\n```\n{}",
                     template.display_name,
                     template.args.join(", "),
                     template.return_type,
-                    *function_doc
+                    template.description
                 );
                 Some(Hover {
                     contents: tower_lsp_server::lsp_types::HoverContents::Markup(MarkupContent {

src/completion/mod.rs

@@ -47,27 +47,27 @@ impl CompletionProvider {
     }
 
     /// Get generic functions completions.
-    pub fn get_function_completions(functions: &[Function]) -> Vec<CompletionItem> {
+    pub fn get_function_completions(functions: &[(Function, String)]) -> Vec<CompletionItem> {
         functions
             .iter()
-            .map(|func| {
-                let template = function_to_template(func);
+            .map(|(func, doc)| {
+                let template = function_to_template(func, doc);
                 template_to_completion(&template)
             })
             .collect()
     }
 }
 
 /// Convert `simplicityhl::parse::Function` to `FunctionTemplate`.
-pub fn function_to_template(func: &Function) -> types::FunctionTemplate {
+pub fn function_to_template(func: &Function, doc: &String) -> types::FunctionTemplate {
     types::FunctionTemplate::simple(
         func.name().to_string(),
         func.params().iter().map(|item| format!("{item}")).collect(),
         match func.ret() {
             Some(ret) => format!("{ret}"),
             None => "()".to_string(),
         },
-        "User defined function",
+        doc,
     )
 }