From b6c896a7c5be517ba12d1b069d58103b6214f09f Mon Sep 17 00:00:00 2001
From: aozhiwei <aozhiwei@kingsome.cn>
Date: Wed, 29 Mar 2023 16:06:30 +0800
Subject: [PATCH] 1

---
 a8/lisp.cc | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/a8/lisp.cc b/a8/lisp.cc
index 441e15e..576ea82 100644
--- a/a8/lisp.cc
+++ b/a8/lisp.cc
@@ -161,7 +161,7 @@ namespace a8
 
         std::shared_ptr<Value> Expr::Compile(const std::string& script, std::shared_ptr<Scope> env)
         {
-            std::vector<List> stack;
+            std::vector<std::tuple<List, int>> stack;
             int pos = 0;
             int depth = -1;
             while (true) {
@@ -171,12 +171,17 @@ namespace a8
                     break;
                 }
                 if (token == "(") {
-                    List new_list = std::make_shared<std::vector<std::shared_ptr<Value>>>();
-                    stack.push_back(new_list);
-                    if (depth >= 0) {
-                        stack.at(depth)->push_back(std::make_shared<Value>(new_list));
-                    }
                     ++depth;
+                    List new_list = std::make_shared<std::vector<std::shared_ptr<Value>>>();
+                    stack.push_back(std::make_tuple(new_list, depth));
+                    auto value = std::make_shared<Value>(new_list);
+                    for (int i = stack.size() - 1; i >= 0; --i) {
+                        auto& tuple = stack.at(i);
+                        if (std::get<1>(tuple) < depth) {
+                            std::get<0>(tuple)->push_back(value);
+                            break;
+                        }
+                    }
                 } else if (token == ")") {
                     --depth;
                 } else {
@@ -184,17 +189,18 @@ namespace a8
                         abort();
                     }
                     double val = 0.0f;
+                    auto& tuple = stack.at(stack.size() - 1);
                     if (sscanf(token.c_str(), "%lf", &val) == 1) {
-                        stack.at(depth)->push_back(std::make_shared<Value>(Atom(val)));
+                        std::get<0>(tuple)->push_back(std::make_shared<Value>(Atom(val)));
                     } else {
                         auto symbol = env->Find(token);
                         if (symbol) {
                             if (!symbol->IsType(ValueType::kCProc)) {
                                 abort();
                             }
-                            stack.at(depth)->push_back(symbol);
+                            std::get<0>(tuple)->push_back(symbol);
                         } else {
-                            stack.at(depth)->push_back(std::make_shared<Value>(Symbol(token)));
+                            std::get<0>(tuple)->push_back(std::make_shared<Value>(Symbol(token)));
                         }
                     }
                 }
@@ -205,7 +211,7 @@ namespace a8
             if (stack.empty()) {
                 abort();
             }
-            return std::make_shared<Value>(stack[0]);
+            return std::make_shared<Value>(std::get<0>(stack[0]));
         }
 
         bool Expr::MaybeExpr(const std::string& script)