From c30e3e67132eb1f92bffff4d787313cfa9652983 Mon Sep 17 00:00:00 2001
From: Andrew Noyes <andrew@weaselab.dev>
Date: Wed, 14 May 2025 19:41:57 -0400
Subject: [PATCH] Fix parsing empty arrays/objects

---
 src/test.cpp | 37 +++++++++++++++++++++++++++++++++++--
 1 file changed, 35 insertions(+), 2 deletions(-)

diff --git a/src/test.cpp b/src/test.cpp
index 64f8b5b..909e7e7 100644
--- a/src/test.cpp
+++ b/src/test.cpp
@@ -143,6 +143,8 @@ enum Symbol : int8_t {
   T_COLON,
   // Nonterminals
   N_VALUE,
+  N_ARRAY_VALUE_OR_END,
+  N_OBJECT_VALUE_OR_END,
   N_ARRAY_MAYBE_CONTINUE,
   N_OBJECT_MAYBE_CONTINUE,
   N_PAST_END, // Must be last nonterminal
@@ -152,6 +154,8 @@ const char *symbolNames[] = {
     "T_STRING",
     "T_COLON",
     "N_VALUE",
+    "N_ARRAY_VALUE_OR_END",
+    "N_OBJECT_VALUE_OR_END",
     "N_ARRAY_MAYBE_CONTINUE",
     "N_OBJECT_MAYBE_CONTINUE",
 };
@@ -531,14 +535,14 @@ private:
     } else if (self->parseLiteral("{")) {
       self->pop();
       self->callbacks->on_begin_object(self->data);
-      if (!self->push({T_STRING, T_COLON, N_VALUE, N_OBJECT_MAYBE_CONTINUE})) {
+      if (!self->push({N_OBJECT_VALUE_OR_END})) {
         return false;
       }
       MUSTTAIL return keepGoing(self);
     } else if (self->parseLiteral("[")) {
       self->pop();
       self->callbacks->on_begin_array(self->data);
-      if (!self->push({N_VALUE, N_ARRAY_MAYBE_CONTINUE})) {
+      if (!self->push({N_ARRAY_VALUE_OR_END})) {
         return false;
       }
       MUSTTAIL return keepGoing(self);
@@ -557,6 +561,33 @@ private:
     }
     return false;
   }
+  static bool arrayOrEnd(Parser2 *self) {
+    if (self->parseLiteral("]")) {
+      self->pop();
+      self->callbacks->on_end_array(self->data);
+      MUSTTAIL return keepGoing(self);
+    } else {
+      self->pop();
+      if (!self->push({N_VALUE, N_ARRAY_MAYBE_CONTINUE})) {
+        return false;
+      }
+      MUSTTAIL return keepGoing(self);
+    }
+  }
+  static bool objectOrEnd(Parser2 *self) {
+    if (self->parseLiteral("}")) {
+      self->pop();
+      self->callbacks->on_end_object(self->data);
+      MUSTTAIL return keepGoing(self);
+    } else {
+      self->pop();
+      if (!self->push({T_STRING, T_COLON, N_VALUE, N_OBJECT_MAYBE_CONTINUE})) {
+        return false;
+      }
+      MUSTTAIL return keepGoing(self);
+    }
+    return false;
+  }
   static bool arrayContinue(Parser2 *self) {
     if (self->parseLiteral(",")) {
       self->pop();
@@ -590,6 +621,8 @@ private:
       /*T_STRING*/ string,
       /*T_COLON*/ colon,
       /*N_VALUE*/ value,
+      /*N_ARRAY_VALUE_OR_END*/ arrayOrEnd,
+      /*N_OBJECT_VALUE_OR_END*/ objectOrEnd,
       /*N_ARRAY_MAYBE_CONTINUE*/ arrayContinue,
       /*N_OBJECT_MAYBE_CONTINUE*/ objectContinue,
   };