From 5f5127d8093da7c1996538562abb7f1a86bc1790 Mon Sep 17 00:00:00 2001
From: Yingchi Long <i@lyc.dev>
Date: Sun, 17 Sep 2023 22:30:38 +0800
Subject: [PATCH] nixd/Syntax: allow expr_app -> expr_simple passthrough

---
 nixd/lib/Syntax/Parser/Parser.y | 18 +++++++++++-------
 nixd/test/Syntax/Basic.cpp      |  2 +-
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/nixd/lib/Syntax/Parser/Parser.y b/nixd/lib/Syntax/Parser/Parser.y
index 1529d0992..d62e07146 100644
--- a/nixd/lib/Syntax/Parser/Parser.y
+++ b/nixd/lib/Syntax/Parser/Parser.y
@@ -63,7 +63,7 @@
 %type <Binds> binds
 %type <AttrPath> attrpath
 %type <Attrs> attrs
-%type <Call> expr_app
+%type <Node> expr_app
 %type <Node> path_start
 %type <SPath> spath
 %type <Uri> uri
@@ -192,14 +192,18 @@ expr_op
 
 expr_app
   : expr_app expr_select {
-    $$->Args.emplace_back($1);
+    if (auto F = dynamic_cast<Call *>($1)) {
+      // If $1 is already a function call, then we insert the arg list
+      F->Args.emplace_back($2);
+    } else {
+      // Otherwise, create a new function
+      auto N = decorateNode(new Call, yylloc, *Data);
+      N->Fn = $1;
+      N->Args = {$2};
+    }
     $$->Range = mkRange(yylloc, *Data);
   }
-  | expr_select {
-    auto N = decorateNode(new Call, yylloc, *Data);
-    N->Fn = $1;
-    $$ = N;
-  }
+  | expr_select
 
 
 expr_select
diff --git a/nixd/test/Syntax/Basic.cpp b/nixd/test/Syntax/Basic.cpp
index f51e09c4d..9b6cf058d 100644
--- a/nixd/test/Syntax/Basic.cpp
+++ b/nixd/test/Syntax/Basic.cpp
@@ -20,7 +20,7 @@ TEST(NixdSyntax, Case1) {
                     .Origin = nix::Pos::Origin(nix::Pos::none_tag())});
   Data->Result = nullptr;
 
-  char Test[] = "let { x = 1; y = 2; } in x\n\0\0";
+  char Test[] = "let x = 1; y = 2; in x\n\0\0";
   parse(Test, strlen(Test) + 2, Data.get());
 }