support construct function by cpp user

TODO.md

@@ -43,4 +43,5 @@
 * [done] 内置函数放置在wamon包名称中
 * 支持using语句以省略外部包的命名空间前缀 - 重构ParseIdentifier，默认情况下不填充本包名称， 然后在语义分析阶段利用using信息依次在本包和using包中查找，找到则重写id。
 * [done] 标准库以包的形式提供
-* [done] 支持简化的函数调用形式@
+* [done] 支持简化的函数调用形式@
+* 重构符号查找规则

include/wamon/executable_block_stmt.h

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <wamon/interpreter.h>
+#include <wamon/variable.h>
+#include <wamon/variable_void.h>
+
+#include <functional>
+
+#include "wamon/ast.h"
+
+namespace wamon {
+
+class ExecutableBlockStmt : public BlockStmt {
+ public:
+  using executable_type = std::function<std::shared_ptr<Variable>(Interpreter&)>;
+
+  ExecutableBlockStmt() = default;
+
+  std::string GetStmtName() override { return "executable_block_stmt"; }
+
+  ExecuteResult Execute(Interpreter& ip) override {
+    if (executable_) {
+      return ExecuteResult::Return(executable_(ip));
+    }
+    return ExecuteResult::Return(GetVoidVariable());
+  }
+
+  void SetExecutable(executable_type&& e) { executable_ = std::move(e); }
+
+  void SetExecutable(const executable_type& e) { executable_ = e; }
+
+ private:
+  executable_type executable_;
+};
+
+}  // namespace wamon

include/wamon/function_def.h

@@ -59,6 +59,8 @@ class FunctionDef {
 
   bool IsDeclaration() const { return block_stmt_ == nullptr; }
 
+  bool IsExecutableBlockStmt() const;
+
  private:
   std::string name_;
   std::vector<ParameterListItem> param_list_;

src/function_def.cc

@@ -1,9 +1,14 @@
 #include "wamon/function_def.h"
 
 #include "wamon/ast.h"
+#include "wamon/executable_block_stmt.h"
 
 namespace wamon {
 
 void FunctionDef::SetBlockStmt(std::unique_ptr<BlockStmt>&& block_stmt) { block_stmt_ = std::move(block_stmt); }
 
+bool FunctionDef::IsExecutableBlockStmt() const {
+  return dynamic_cast<ExecutableBlockStmt*>(block_stmt_.get()) != nullptr;
+}
+
 }  // namespace wamon

src/type_checker.cc

@@ -1,6 +1,9 @@
 #include "wamon/type_checker.h"
 
+#include <wamon/ast.h>
+
 #include <cassert>
+#include <cstddef>
 #include <string>
 #include <vector>
 
@@ -122,6 +125,10 @@ void TypeChecker::CheckFunctions() {
     if (capture_ids.empty() == false) {
       continue;
     }
+    // 跳过用户实现BlockStmt的函数
+    if (each.second->IsExecutableBlockStmt()) {
+      continue;
+    }
     // 首先进行上下文相关的检测、表达式类型检测、语句合法性检测
     auto func_context = std::make_unique<Context>(each.second->name_);
     static_analyzer_.RegisterFuncParamsToContext(each.second->param_list_, func_context.get());

test/executable_block_stmt_test.cc

@@ -0,0 +1,77 @@
+#include "wamon/executable_block_stmt.h"
+
+#include <wamon/ast.h>
+#include <wamon/package_unit.h>
+#include <wamon/type_checker.h>
+#include <wamon/variable_int.h>
+#include <wamon/variable_string.h>
+
+#include <memory>
+#include <string>
+
+#include "gtest/gtest.h"
+#include "wamon/function_def.h"
+#include "wamon/interpreter.h"
+#include "wamon/parser.h"
+#include "wamon/scanner.h"
+#include "wamon/type.h"
+#include "wamon/variable.h"
+
+using namespace wamon;
+
+std::shared_ptr<FunctionDef> generate_func_for_test() {
+  std::shared_ptr<FunctionDef> fd(new FunctionDef("my_fn"));
+  fd->AddParamList({
+      .name = "main$param_a",
+      .type = TypeFactory<int>::Get(),
+      .is_ref = false,
+  });
+
+  fd->AddParamList({
+      .name = "main$param_ref",
+      .type = TypeFactory<std::string>::Get(),
+      .is_ref = true,
+  });
+
+  fd->SetReturnType(TypeFactory<int>::Get());
+
+  auto executable_block = std::make_unique<ExecutableBlockStmt>();
+  executable_block->SetExecutable([](Interpreter& ip) -> std::shared_ptr<Variable> {
+    auto va = ip.FindVariableById("main$param_a");
+    auto vref = ip.FindVariableById("main$param_ref");
+    va = ip.CallFunctionByName("main$update_value_from_script", {va});
+    int ret = AsIntVariable(va)->GetValue();
+    AsStringVariable(vref)->SetValue("changed");
+    return std::make_shared<IntVariable>(ret * 2, Variable::ValueCategory::RValue, "");
+  });
+
+  fd->SetBlockStmt(std::move(executable_block));
+  return fd;
+}
+
+TEST(executable_block_stmt, basic) {
+  std::string script = R"(
+    package main;
+
+    func update_value_from_script(int a) -> int {
+      return a + 10;
+    }
+  )";
+
+  Scanner scan;
+  auto tokens = scan.Scan(script);
+  auto pu = Parse(tokens);
+  pu.AddFuncDef(generate_func_for_test());
+  pu = MergePackageUnits(std::move(pu));
+  auto va = std::make_shared<IntVariable>(1, Variable::ValueCategory::RValue, "");
+  auto vb = std::make_shared<StringVariable>("hello", Variable::ValueCategory::LValue, "");
+  TypeChecker tc(pu);
+  std::string reason;
+  bool succ = tc.CheckAll(reason);
+  EXPECT_EQ(succ, true) << reason;
+
+  Interpreter ip(pu);
+  auto ret = ip.CallFunctionByName("main$my_fn", {va, vb});
+  EXPECT_EQ(AsIntVariable((ret))->GetValue(), 22);
+  EXPECT_EQ(AsStringVariable(vb)->GetValue(), "changed");
+}