From a8557125c48965de525f68d081c9147a13c22fae Mon Sep 17 00:00:00 2001
From: Sameer Rahmani <lxsameer@gnu.org>
Date: Mon, 3 Aug 2020 20:21:46 +0100
Subject: [PATCH] Add the mapping for builtins special forms to namespace

---
 include/serene/list.hpp              |  2 +-
 include/serene/namespace.hpp         | 12 +++++++++++-
 include/serene/special_forms/def.hpp |  1 +
 src/list.cpp                         |  2 +-
 src/namespace.cpp                    | 10 ++++++++++
 src/special_forms/def.cpp            | 27 +++++++++++++++++++++++++++
 6 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/include/serene/list.hpp b/include/serene/list.hpp
index aaa72b3..546c866 100644
--- a/include/serene/list.hpp
+++ b/include/serene/list.hpp
@@ -44,7 +44,7 @@ public:
   void cons(ast_node f);
   void append(ast_node t);
 
-  std::optional<ast_node> at(uint index);
+  std::optional<ast_node> at(uint index) const;
 
   llvm::Value *codegen(Compiler &compiler, State &state) override;
 };
diff --git a/include/serene/namespace.hpp b/include/serene/namespace.hpp
index 3d8e148..980a418 100644
--- a/include/serene/namespace.hpp
+++ b/include/serene/namespace.hpp
@@ -37,10 +37,20 @@
 #endif
 
 namespace serene {
+class AExpr;
+class List;
+class Compiler;
+class State;
+
 class Namespace {
-private:
+  // Why not ast_node ? because i have to include expr.hpp which
+  // causes a circular dependency
+  using MakerFn =
+      std::function<std::shared_ptr<AExpr>(Compiler &, State &, const List *)>;
+  using BuiltinMap = std::map<std::string, MakerFn>;
   std::unique_ptr<llvm::Module> module;
   std::map<std::string, llvm::Value *> scope;
+  static BuiltinMap builtins;
 
 public:
   std::string name;
diff --git a/include/serene/special_forms/def.hpp b/include/serene/special_forms/def.hpp
index 8e15644..048ffb1 100644
--- a/include/serene/special_forms/def.hpp
+++ b/include/serene/special_forms/def.hpp
@@ -53,6 +53,7 @@ public:
   Def(serene::Symbol *symbol_, AExpr *value_);
   std::string string_repr() const override;
   llvm::Value *codegen(Compiler &compiler, State &state) override;
+  static ast_node make(Compiler &compiler, State &state, const List *args);
   ~Def();
 };
 
diff --git a/src/list.cpp b/src/list.cpp
index 309cc53..db3f798 100644
--- a/src/list.cpp
+++ b/src/list.cpp
@@ -35,7 +35,7 @@ using namespace llvm;
 
 namespace serene {
 
-std::optional<ast_node> List::at(uint index) {
+std::optional<ast_node> List::at(uint index) const {
   if (index >= nodes_.size()) {
     return std::nullopt;
   }
diff --git a/src/namespace.cpp b/src/namespace.cpp
index a65b938..20c111f 100644
--- a/src/namespace.cpp
+++ b/src/namespace.cpp
@@ -24,6 +24,7 @@
 
 #include "serene/expr.hpp"
 #include "serene/llvm/IR/Value.h"
+#include "serene/special_forms/def.hpp"
 #include <fmt/core.h>
 #include <string>
 
@@ -32,6 +33,15 @@ using namespace llvm;
 
 namespace serene {
 
+Namespace::BuiltinMap Namespace::builtins = [] {
+  NAMESPACE_LOG("Initializing builtins map.");
+  BuiltinMap exprs_map;
+  // exprs_map.insert(std::make_pair("def", &special_forms::Def::make));
+  // MakerFn def = ;
+  exprs_map["def"] = special_forms::Def::make;
+  return exprs_map;
+}();
+
 Value *Namespace::lookup(const string &name) { return scope[name]; };
 
 void Namespace::insert_symbol(const string &name, Value *v) { scope[name] = v; }
diff --git a/src/special_forms/def.cpp b/src/special_forms/def.cpp
index 654a099..572f12d 100644
--- a/src/special_forms/def.cpp
+++ b/src/special_forms/def.cpp
@@ -24,6 +24,7 @@
 
 #include "serene/special_forms/def.hpp"
 #include "serene/compiler.hpp"
+#include "serene/list.hpp"
 #include "serene/llvm/IR/Value.h"
 #include "serene/namespace.hpp"
 #include "serene/state.hpp"
@@ -38,6 +39,32 @@ using namespace llvm;
 namespace serene {
 namespace special_forms {
 
+ast_node Def::make(Compiler &compiler, State &state, const List *args) {
+  auto def_ptr = args->at(0).value_or(nullptr);
+  auto name_ptr = args->at(1).value_or(nullptr);
+  auto body_ptr = args->at(2).value_or(nullptr);
+
+  if (def_ptr && def_ptr->id() == symbol &&
+      static_cast<Symbol *>(def_ptr.get())->name() == "def") {
+
+    if (!name_ptr && def_ptr->id() != symbol) {
+      compiler.log_error("First argument of 'def' has to be a symbol.");
+      return nullptr;
+    }
+
+    if (!body_ptr) {
+      compiler.log_error("'def' needs 3 arguments, two has been given.");
+      return nullptr;
+    }
+
+    return make_unique<Def>(static_cast<Symbol *>(name_ptr.get()),
+                            body_ptr.get());
+  }
+
+  compiler.log_error("Calling 'def' with wrong parameters");
+  return nullptr;
+};
+
 Def::Def(Symbol *symbol_, AExpr *value_) : m_sym(symbol_), m_value(value_) {}
 
 string Def::string_repr() const {