WIP function arguments

Author: TimoFreiberg

crates/ra_assists/src/handlers/add_function.rs

@@ -5,6 +5,7 @@ use ra_syntax::{
 
 use crate::{Assist, AssistCtx, AssistId};
 use ast::{CallExpr, Expr};
+use hir::ModuleDef;
 use ra_fmt::leading_indent;
 
 // Assist: add_function
@@ -72,7 +73,7 @@ fn generate_fn(ctx: &AssistCtx, call: &CallExpr) -> Option<(String, TextUnit, Te
     let fn_generics = fn_generics(&call)?;
     fn_buf.push_str(&fn_generics);
 
-    let fn_args = fn_args()?;
+    let fn_args = fn_args(ctx, &call)?;
     fn_buf.push_str(&fn_args);
 
     fn_buf.push_str(" {\n");
@@ -99,10 +100,34 @@ fn fn_generics(_call: &CallExpr) -> Option<String> {
     Some("".into())
 }
 
-fn fn_args() -> Option<String> {
+fn fn_args(ctx: &AssistCtx, _call: &CallExpr) -> Option<String> {
+    let arg_list = _call.syntax().descendants().find_map(ast::ArgList::cast)?;
+    for arg in arg_list.args() {
+        match &arg {
+            Expr::CallExpr(call_expr) => {
+                arg_for_call(ctx, call_expr);
+            }
+            _ => {}
+        }
+        dbg!(&arg);
+    }
     Some("()".into())
 }
 
+fn arg_for_call(ctx: &AssistCtx, call_expr: &CallExpr) -> Option<String> {
+    let path = call_expr.syntax().descendants().find_map(ast::Path::cast)?;
+    let type_string = match ctx.sema.resolve_path(&path)? {
+        hir::PathResolution::Def(ModuleDef::Function(f)) => {
+            let _ret_type = dbg!(f.ret_type(ctx.sema.db));
+            // TODO: find out how to print this
+            String::new()
+        }
+        _ => return None,
+    };
+
+    Some(format!("arg: {}", type_string))
+}
+
 /// Returns the position inside the current mod or file
 /// directly after the current block
 /// We want to write the generated function directly after

crates/ra_hir/src/code_model.rs

@@ -610,6 +610,10 @@ impl Function {
         db.function_data(self.id).params.clone()
     }
 
+    pub fn ret_type(self, db: &dyn HirDatabase) -> TypeRef {
+        db.function_data(self.id).ret_type.clone()
+    }
+
     pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
         let _p = profile("Function::diagnostics");
         let infer = db.infer(self.id.into());