added jet signature for hover

Author: gerau

src/backend.rs

@@ -211,6 +211,9 @@ impl LanguageServer for Backend {
             else {
                 return Ok(None);
             };
+            let Ok((start, end)) = span_to_positions(call.span()) else {
+                return Ok(None);
+            };
 
             match call.name() {
                 parse::CallName::Jet(jet) => {
@@ -219,15 +222,21 @@ impl LanguageServer for Backend {
                     ) else {
                         return Ok(None);
                     };
-                    let Ok((start, end)) = span_to_positions(call.span()) else {
-                        return Ok(None);
-                    };
+
+                    let template = completion::jet::jet_to_template(element);
+                    let description = format!(
+                        "```simplicityhl\nfn jet::{}({}) -> {}\n```\n{}",
+                        template.display_name,
+                        template.args.join(", "),
+                        template.return_type,
+                        completion::jet::documentation(element)
+                    );
 
                     return Ok(Some(Hover {
                         contents: tower_lsp_server::lsp_types::HoverContents::Markup(
                             MarkupContent {
                                 kind: MarkupKind::Markdown,
-                                value: completion::jet::documentation(element).to_string(),
+                                value: description,
                             },
                         ),
                         range: Some(Range { start, end }),

src/completion/jet.rs

@@ -5,21 +5,19 @@ use simplicityhl::simplicity::jet::Elements;
 
 /// Convert all jets to `FunctionCompletionTemplate`.
 pub fn get_jets_completions() -> Vec<types::FunctionTemplate> {
-    Elements::ALL
-        .iter()
-        .copied()
-        .map(|jet| {
-            types::FunctionTemplate::simple(
-                jet.to_string(),
-                jet::source_type(jet)
-                    .iter()
-                    .map(|item| format!("{item}"))
-                    .collect::<Vec<String>>(),
-                jet::target_type(jet).to_string().as_str(),
-                documentation(jet),
-            )
-        })
-        .collect()
+    Elements::ALL.iter().copied().map(jet_to_template).collect()
+}
+
+pub fn jet_to_template(jet: Elements) -> types::FunctionTemplate {
+    types::FunctionTemplate::simple(
+        jet.to_string(),
+        jet::source_type(jet)
+            .iter()
+            .map(|item| format!("{item}"))
+            .collect::<Vec<String>>(),
+        jet::target_type(jet).to_string().as_str(),
+        documentation(jet),
+    )
 }
 
 // copied from https://github.com/BlockstreamResearch/SimplicityHL/blob/master/codegen/src/jet.rs