ADD: function literal.

doc/grammar.bnf

@@ -5,5 +5,9 @@ EXPR ::=
 | ident
 | VARDECL
 | FUNCALL
+| LAMBDA
 VARDECL ::= opar decl ident EXPR cpar
-FUNCALL ::= opar ident EXPR* cpar
+FUNCALL ::= opar EXPR EXPR* cpar
+LAMBDA ::= opar lambda opar PARAMS cpar BODY cpar
+PARAMS ::= ident*
+BODY ::= EXPR*

examples/fun.gri

@@ -0,0 +1,10 @@
+;; declare lambda
+($ a (-> (x) (* x 2)))
+(assert-eq? 14 (a 7))
+
+;; high order function
+($ b (-> (x y) (x (x y))))
+(assert-eq? 12 (b a 3))
+
+;; calling function literal
+(assert-eq? 7 ( (-> (x y) (+ x y 1)) 2 4 ))

lib/core.cpp

@@ -195,12 +195,14 @@ extern "C" void lib_bool(grino::Loader& loader)
     return grino::Value::make_bool(args[0]->loc(), !args[0]->as_bool());
   });
 
-  loader.add_static("and", [](auto& compiler, auto node, auto& program){
+  loader.add_static("and", [](auto& compiler, auto node,
+                              auto& program,
+                              auto& sym){
     std::vector<size_t> to_false;
 
     for (size_t i=1; i<node->size(); i++)
       {
-        compiler.compile(node->child(i).lock(), program);
+        compiler.compile(node->child(i).lock(), program, sym);
         to_false.push_back(program.size());
         program.push_instr(grino::OPCODE_BRF, 0 /* to false */);
       }
@@ -223,12 +225,13 @@ extern "C" void lib_bool(grino::Loader& loader)
     program.set_param(to_end, program.size());
   });
 
-  loader.add_static("or", [](auto& compiler, auto node, auto& program){
+  loader.add_static("or", [](auto& compiler, auto node,
+                             auto& program, auto& sym){
     std::vector<size_t> to_true;
 
     for (size_t i=1; i<node->size(); i++)
       {
-        compiler.compile(node->child(i).lock(), program);
+        compiler.compile(node->child(i).lock(), program, sym);
         program.push_instr(grino::OPCODE_NOT);
         to_true.push_back(program.size());
         program.push_instr(grino::OPCODE_BRF, 0 /* to true */);

src/Compiler.cpp

@@ -6,10 +6,10 @@
 
 namespace grino
 {
-  /*explicit*/ Compiler::Compiler(Logger& logger, SymTable& sym)
+  /*explicit*/ Compiler::Compiler(Logger& logger)
     : m_logger { logger }
-    , m_sym { sym }
   {
+    enter_scope();
   }
 
   /*virtual*/ Compiler::~Compiler()
@@ -17,18 +17,31 @@ namespace grino
   }
 
   void Compiler::compile(std::shared_ptr<Node> node,
-                         Program& program)
+                         Program& program,
+                         SymTable& sym)
   {
     switch (node->type())
       {
       case NODE_MODULE: {
         for (size_t i=0; i<node->size(); i++)
           {
-            compile(node->child(i).lock(), program);
+            compile(node->child(i).lock(), program, sym);
             program.push_instr(OPCODE_POP);
           }
       } break;
 
+      case NODE_BODY: {
+        for (size_t i=0; i<node->size(); i++)
+          {
+            compile(node->child(i).lock(), program, sym);
+
+            if (i < node->size() - 1)
+              {
+                program.push_instr(OPCODE_POP);
+              }
+          }
+      } break;
+
       case NODE_FUNCALL: {
         std::string ident = node->child(0).lock()->repr();
 
@@ -36,13 +49,13 @@ namespace grino
             itr != std::end(m_statics))
           {
             auto fun = itr->second;
-            fun->call(*this, node, program);
+            fun->call(*this, node, program, sym);
           }
         else
           {
             for (size_t i=0; i<node->size(); i++)
               {
-                compile(node->child(i).lock(), program);
+                compile(node->child(i).lock(), program, sym);
               }
 
             program.push_instr(OPCODE_CALL, node->size() - 1);
@@ -50,6 +63,32 @@ namespace grino
 
       } break;
 
+      case NODE_LAMBDA: {
+        auto params = node->child(0).lock();
+
+        enter_scope();
+
+        for (size_t i=0; i<params->size(); i++)
+          {
+            auto param = params->child(i).lock();
+            std::string ident = param->repr();
+            sym.declare(param->loc(), ident, get_local_address(),
+                        m_scope.size());
+          }
+
+        auto prog = std::make_shared<Program>();
+        auto body = node->child(1).lock();
+        compile(body, *prog, sym);
+
+        prog->push_instr(OPCODE_RET);
+
+        leave_scope();
+        sym.purge(m_scope.size());
+
+        program.push_value(Value::make_program(node->loc(), prog));
+        program.push_instr(OPCODE_MK_FUN);
+      } break;
+
       case NODE_BOOL: {
         std::string repr = node->repr();
         auto value = Value::make_bool(node->loc(), repr == "true");
@@ -71,15 +110,15 @@ namespace grino
         auto expr = node->child(1).lock();
         size_t address = get_local_address();
 
-        compile(expr, program);
+        compile(expr, program, sym);
 
-        m_sym.declare(node->loc(), ident, address);
+        sym.declare(node->loc(), ident, address, m_scope.size());
         program.push_instr(OPCODE_STORE_LOCAL, address);
       } break;
 
       case NODE_IDENT: {
         std::string ident = node->repr();
-        auto entry = m_sym.find(ident);
+        auto entry = sym.find(ident, m_scope.size());
 
         if (entry == std::nullopt)
           {
@@ -114,8 +153,18 @@ namespace grino
 
   size_t Compiler::get_local_address()
   {
-    static size_t addr = 0;
-    addr++;
-    return addr - 1;
+    m_scope.back() += 1;
+    return m_scope.back() - 1;
+  }
+
+  void Compiler::enter_scope()
+  {
+    m_scope.push_back(0);
+  }
+
+  void Compiler::leave_scope()
+  {
+    assert(m_scope.empty() == false);
+    m_scope.pop_back();
   }
 }

src/Compiler.hpp

@@ -17,22 +17,26 @@ namespace grino
   class Compiler
   {
   public:
-    explicit Compiler(Logger& logger, SymTable& sym);
+    explicit Compiler(Logger& logger);
     virtual ~Compiler();
 
     void compile(std::shared_ptr<Node> node,
-                 Program& program);
+                 Program& program,
+                 SymTable& sym);
 
     void add_static_func(std::string const& name,
                          std::shared_ptr<StaticFunction> fun);
 
   private:
     Logger& m_logger;
-    SymTable& m_sym;
     std::unordered_map<std::string,
                        std::shared_ptr<StaticFunction>> m_statics;
 
+    std::vector<size_t> m_scope;
+
     size_t get_local_address();
+    void enter_scope();
+    void leave_scope();
   };
 }
 

src/Function.cpp

@@ -1,5 +1,6 @@
 #include "Function.hpp"
 #include "Value.hpp"
+#include "Program.hpp"
 
 namespace grino
 {
@@ -8,10 +9,25 @@ namespace grino
   {
   }
 
+  /*explicit*/ Function::Function(std::shared_ptr<Program> prog)
+    : m_prog { prog }
+  {
+  }
+
   /*virtual*/ Function::~Function()
   {
   }
 
+  bool Function::is_native() const
+  {
+    return m_native != nullptr;
+  }
+
+  std::shared_ptr<Program> Function::program() const
+  {
+    return m_prog;
+  }
+
   value_t Function::call(args_t args)
   {
     assert(m_native);

src/Function.hpp

@@ -6,6 +6,7 @@
 namespace grino
 {
   class Value;
+  class Program;
 
   using value_t = std::shared_ptr<Value>;
   using args_t = std::vector<value_t>;
@@ -15,12 +16,16 @@ namespace grino
   {
   public:
     explicit Function(native_t native);
+    explicit Function(std::shared_ptr<Program> prog);
     virtual ~Function();
 
+    bool is_native() const;
+    std::shared_ptr<Program> program() const;
     value_t call(args_t args);
 
   private:
     native_t m_native;
+    std::shared_ptr<Program> m_prog;
   };
 }
 

src/Lexer.cpp

@@ -11,6 +11,7 @@ namespace grino
     add_text(NODE_CPAR, ")", false);
     add_text(NODE_DECL, "$", false);
 
+    add_keyword(NODE_LAMBDA, "->", false);
     add_keyword(NODE_BOOL, "true", true);
     add_keyword(NODE_BOOL, "false", true);
 

src/Loader.cpp

@@ -43,7 +43,7 @@ namespace grino
     grino::Loc loc {"???", 0};
 
     m_vm.set_heap(addr, grino::Value::make_native_function(loc, native));
-    m_sym_table.declare_object(loc, name, addr);
+    m_sym_table.declare_object(loc, name, addr, 0);
   }
 
   void Loader::add_static(std::string const& name, static_fun_t fun)

src/Node.hpp

@@ -13,7 +13,10 @@
     G(NODE_IDENT),                              \
     G(NODE_OPAR),                               \
     G(NODE_CPAR),                               \
-    G(NODE_DECL),
+    G(NODE_DECL),                               \
+    G(NODE_LAMBDA),                             \
+    G(NODE_PARAMS),                             \
+    G(NODE_BODY),
 
 namespace grino
 {

src/Parser.cpp

@@ -1,4 +1,5 @@
 #include "Parser.hpp"
+#include "src/Node.hpp"
 #include "src/mutils.hpp"
 
 namespace grino
@@ -117,16 +118,21 @@ namespace grino
 
   std::shared_ptr<Node> Parser::parse_expr()
   {
-    if (type_is({NODE_OPAR, NODE_IDENT}))
-      {
-        return parse_funcall();
-      }
-
     if (type_is({NODE_OPAR, NODE_DECL}))
       {
         return parse_vardecl();
       }
 
+    if (type_is({NODE_OPAR, NODE_LAMBDA}))
+      {
+        return parse_lambda();
+      }
+
+    if (type_is(NODE_OPAR))
+      {
+        return parse_funcall();
+      }
+
     if (type_is(NODE_IDENT)
         || type_is(NODE_BOOL)
         || type_is(NODE_INT))
@@ -163,7 +169,7 @@ namespace grino
     consume(NODE_OPAR);
 
     auto node = make_node(NODE_FUNCALL);
-    node->add_child(consume(NODE_IDENT));
+    node->add_child(parse_expr());
 
     while (!type_is(NODE_CPAR))
       {
@@ -174,4 +180,44 @@ namespace grino
 
     return node;
   }
+
+  std::shared_ptr<Node> Parser::parse_lambda()
+  {
+    consume(NODE_OPAR);
+    auto node = consume(NODE_LAMBDA);
+
+    consume(NODE_OPAR);
+    node->add_child(parse_params());
+    consume(NODE_CPAR);
+
+    node->add_child(parse_body());
+    consume(NODE_CPAR);
+
+    return node;
+  }
+
+  std::shared_ptr<Node> Parser::parse_params()
+  {
+    auto node = make_node(NODE_PARAMS);
+
+    while (!type_is(NODE_CPAR))
+      {
+        node->add_child(consume(NODE_IDENT));
+      }
+
+    return node;
+  }
+
+  std::shared_ptr<Node> Parser::parse_body()
+  {
+    auto node = make_node(NODE_BODY);
+
+    while (!type_is(NODE_CPAR))
+      {
+        node->add_child(parse_expr());
+      }
+
+    return node;
+  }
+
 }

src/Parser.hpp

@@ -36,6 +36,9 @@ namespace grino
     std::shared_ptr<Node> parse_expr();
     std::shared_ptr<Node> parse_vardecl();
     std::shared_ptr<Node> parse_funcall();
+    std::shared_ptr<Node> parse_lambda();
+    std::shared_ptr<Node> parse_params();
+    std::shared_ptr<Node> parse_body();
   };
 }
 

src/Program.cpp

@@ -54,6 +54,12 @@ namespace grino
     return m_constants[index];
   }
 
+  void Program::push_value(std::shared_ptr<Value> value)
+  {
+    size_t addr = push_constant(value);
+    push_instr(OPCODE_LOAD_CONST, addr);
+  }
+
   std::string Program::string() const
   {
     std::stringstream ss;

src/Program.hpp

@@ -31,6 +31,8 @@ namespace grino
     size_t push_constant(std::shared_ptr<Value> value);
     std::shared_ptr<Value> constant(size_t index) const;
 
+    void push_value(std::shared_ptr<Value> value);
+
     std::string string() const;
 
   private:

src/StaticFunction.cpp

@@ -14,8 +14,9 @@ namespace grino
 
   void StaticFunction::call(Compiler& compiler,
                             node_t node,
-                            prog_t prog)
+                            prog_t prog,
+                            SymTable& sym)
   {
-    m_fun(compiler, node, prog);
+    m_fun(compiler, node, prog,sym);
   }
 }

src/StaticFunction.hpp

@@ -5,13 +5,15 @@
 #include "Function.hpp"
 #include "Node.hpp"
 #include "Program.hpp"
+#include "SymTable.hpp"
 
 namespace grino
 {
   class Compiler;
   using node_t = std::shared_ptr<Node>;
   using prog_t = Program&;
-  using static_fun_t = std::function<void (Compiler&, node_t, prog_t)>;
+  using sym_t = SymTable&;
+  using static_fun_t = std::function<void (Compiler&, node_t, prog_t, sym_t)>;
 
   class StaticFunction
   {
@@ -19,7 +21,7 @@ namespace grino
     explicit StaticFunction(static_fun_t fun);
     virtual ~StaticFunction();
 
-    void call(Compiler& compiler, node_t node, prog_t prog);
+    void call(Compiler& compiler, node_t node, prog_t prog, sym_t sym);
 
   private:
     static_fun_t m_fun;

src/SymTable.cpp

@@ -11,9 +11,11 @@ namespace grino
   {
   }
 
-  void SymTable::declare(Loc const& loc, std::string const& name, size_t addr)
+  void SymTable::declare(Loc const& loc, std::string const& name, size_t addr,
+                         size_t scope)
   {
-    if (find(name))
+    if (auto e = find(name, scope);
+        e && e->scope == scope)
       {
         m_logger.log<symbolic_error>(LOG_ERROR, loc, "'"
                                      + name
@@ -24,29 +26,46 @@ namespace grino
     entry.addr = addr;
     entry.name = name;
     entry.is_object = false;
+    entry.scope = scope;
 
     m_entries.push_back(entry);
   }
 
   void SymTable::declare_object(Loc const& loc,
                                 std::string const& name,
-                                size_t addr)
+                                size_t addr,
+                                size_t scope)
   {
-    declare(loc, name, addr);
+    declare(loc, name, addr, scope);
     m_entries.back().is_object = true;
   }
 
-  std::optional<SymEntry> SymTable::find(std::string const& name)
+  std::optional<SymEntry> SymTable::find(std::string const& name, size_t scope)
   {
+    std::optional<SymEntry> entry;
+
     for (size_t i=0; i<m_entries.size(); i++)
       {
-        if (m_entries[i].name == name)
+        if (m_entries[i].name == name
+            && m_entries[i].scope <= scope
+            && (!entry || m_entries[i].scope > entry->scope))
           {
-            return m_entries[i];
+            entry = m_entries[i];
           }
       }
 
-    return std::nullopt;
+    return entry;
+  }
+
+  void SymTable::purge(size_t scope)
+  {
+    auto itr = std::remove_if(std::begin(m_entries),
+                              std::end(m_entries),
+                              [scope](auto const& entry){
+                                return entry.scope > scope;
+                              });
+
+    m_entries.erase(itr, std::end(m_entries));
   }
 
   std::string SymTable::string() const

src/SymTable.hpp

@@ -10,6 +10,7 @@ namespace grino
     std::string name;
     bool is_object; /* object are on the heap instead of the stack */
     size_t addr; /* address on the heap if object, local address otherwise */
+    size_t scope;
   };
 
   GRINO_ERROR(symbolic_error);
@@ -20,10 +21,15 @@ namespace grino
     explicit SymTable(Logger& logger);
     virtual ~SymTable();
 
-    void declare(Loc const& loc, std::string const& name, size_t addr);
-    void declare_object(Loc const& loc, std::string const& name, size_t addr);
+    void declare(Loc const& loc, std::string const& name, size_t addr,
+                 size_t scope);
 
-    std::optional<SymEntry> find(std::string const& name);
+    void declare_object(Loc const& loc, std::string const& name, size_t addr,
+                        size_t scope);
+
+    std::optional<SymEntry> find(std::string const& name, size_t scope);
+
+    void purge(size_t scope);
 
     std::string string() const;
 

src/VM.cpp

@@ -1,33 +1,52 @@
 #include "VM.hpp"
 #include "src/opcodes.hpp"
+#include <optional>
 
 namespace grino
 {
-  /*explicit*/ VM::VM(Logger& logger)
+  /*explicit*/ VM::VM(Logger& logger, Program& program)
     : m_logger { logger }
   {
-    m_frames.push_back(Frame {});
+    Frame frame;
+    frame.pc = m_pc;
+    frame.sp = m_sp;
+    frame.program = &program;
+    m_frames.push_back(frame);
   }
 
   /*virtual*/ VM::~VM()
   {
   }
 
-  void VM::run(Program& program)
+  void VM::run()
   {
     m_bp = 0;
     m_sp = 0;
     m_pc = 0;
 
-    while (m_pc < program.size())
+    while (m_pc < program().size())
       {
-        Instr instr = program.get(m_pc);
+        Instr instr = program().get(m_pc);
 
         switch (instr.opcode)
           {
+          case OPCODE_MK_FUN: {
+            auto prog_val = program().constant(pop());
+            auto prog = prog_val->as_program();
+            auto fun_val = Value::make_function(prog_val->loc(), prog);
+            size_t addr = m_heap.size();
+            set_heap(addr, fun_val);
+
+            auto ref = Value::make_ref(prog_val->loc(), addr);
+            push(program().push_constant(ref));
+
+            m_pc++;
+
+          } break;
+
           case OPCODE_NOT: {
-            auto val = program.constant(pop());
-            push(program.push_constant(Value::make_bool(val->loc(),
+            auto val = program().constant(pop());
+            push(program().push_constant(Value::make_bool(val->loc(),
                                                         !val->as_bool())));
             m_pc++;
           } break;
@@ -37,7 +56,7 @@ namespace grino
           } break;
 
           case OPCODE_BRF: {
-            auto val = program.constant(pop())->as_bool();
+            auto val = program().constant(pop())->as_bool();
             size_t addr = *instr.param;
 
             if (!val)
@@ -62,21 +81,39 @@ namespace grino
 
           case OPCODE_STORE_LOCAL: {
             size_t addr = *instr.param;
-            auto value = program.constant(top());
+            auto value = program().constant(top());
             set_local(addr, value);
             m_pc++;
           } break;
 
           case OPCODE_LOAD_LOCAL: {
             size_t addr = *instr.param;
-            push(program.push_constant(local(addr)));
+            push(program().push_constant(local(addr)));
             m_pc++;
           } break;
 
           case OPCODE_LOAD_OBJ: {
             size_t addr = *instr.param;
             auto ref = Value::make_ref(Loc {"???", 0}, addr);
-            push(program.push_constant(ref));
+            push(program().push_constant(ref));
+            m_pc++;
+          } break;
+
+          case OPCODE_RET: {
+            m_pc = m_frames.back().pc;
+            size_t old_sp = m_frames.back().sp;
+
+            auto ret_val = program().constant(m_stack[m_sp - 1]);
+
+            m_frames.pop_back();
+
+            while (m_sp > old_sp)
+              {
+                pop();
+              }
+
+            push(program().push_constant(ret_val));
+
             m_pc++;
           } break;
 
@@ -87,18 +124,33 @@ namespace grino
 
             for (size_t i=0; i<N; i++)
               {
-                args.insert(std::begin(args), program.constant(pop()));
+                args.insert(std::begin(args), program().constant(pop()));
               }
 
-            size_t ref = program.constant(pop())->as_ref();
+            size_t ref = program().constant(pop())->as_ref();
             auto fun = heap(ref)->as_function();
 
-            auto ret = fun->call(args);
+            if (fun->is_native())
+              {
+                auto ret = fun->call(args);
+                push(program().push_constant(ret));
+                m_pc++;
+              }
+            else
+              {
+                Frame frame;
+                frame.pc = m_pc;
+                frame.sp = m_sp;
+                frame.program = fun->program().get();
+                m_frames.push_back(frame);
 
-            push(program.push_constant(ret));
-
-            m_pc++;
+                for (size_t i=0; i<args.size(); i++)
+                  {
+                    set_local(i, args[i]);
+                  }
 
+                m_pc = 0;
+              }
           } break;
 
           default:
@@ -110,6 +162,7 @@ namespace grino
       }
   }
 
+
   std::string VM::string() const
   {
     std::stringstream ss;
@@ -173,4 +226,10 @@ namespace grino
     size_t addr = m_stack[m_sp - 1];
     return addr;
   }
+
+  Program& VM::program() const
+  {
+    assert(m_frames.back().program);
+    return *m_frames.back().program;
+  }
 }

src/VM.hpp

@@ -12,18 +12,21 @@ namespace grino
   GRINO_ERROR(execution_error);
 
   struct Frame {
+    size_t pc;
+    size_t sp;
+    Program* program;
     std::unordered_map<size_t, std::shared_ptr<Value>> locals;
   };
 
   class VM
   {
   public:
-    explicit VM(Logger& logger);
+    explicit VM(Logger& logger, Program& program);
     virtual ~VM();
 
     size_t heap_size() const { return m_heap.size(); }
 
-    void run(Program& program);
+    void run();
 
     std::string string() const;
 
@@ -36,8 +39,10 @@ namespace grino
                   std::shared_ptr<Value> value);
   private:
     Logger& m_logger;
+
     std::array<size_t, STACK_SIZE> m_stack;
     std::unordered_map<size_t, std::shared_ptr<Value>> m_heap;
+
     std::vector<Frame> m_frames;
 
     size_t m_sp; /* stack pointer */
@@ -48,6 +53,7 @@ namespace grino
     size_t pop();
     size_t top();
 
+    Program& program() const;
 
   };
 }

src/Value.cpp

@@ -1,4 +1,5 @@
 #include "Value.hpp"
+#include "Program.hpp"
 
 namespace grino
 {
@@ -35,6 +36,16 @@ namespace grino
     return value;
   }
 
+  /*static*/ std::shared_ptr<Value>
+  Value::make_function(Loc const& loc,
+                       std::shared_ptr<Program> val)
+  {
+    auto value = std::make_shared<Value>(loc);
+    value->m_type = TYPE_FUNCTION;
+    value->m_function_val = std::make_shared<Function>(val);
+    return value;
+  }
+
   /*static*/ std::shared_ptr<Value> Value::make_ref(Loc const& loc, size_t val)
   {
     auto value = std::make_shared<Value>(loc);
@@ -43,6 +54,21 @@ namespace grino
     return value;
   }
 
+  /*static*/
+  std::shared_ptr<Value> Value::make_program(Loc const& loc,
+                                             std::shared_ptr<Program> val)
+  {
+    auto value = std::make_shared<Value>(loc);
+    value->m_type = TYPE_PROGRAM;
+    value->m_program_val = val;
+    return value;
+  }
+
+  std::shared_ptr<Program> Value::as_program() const
+  {
+    return m_program_val;
+  }
+
   std::string Value::string() const
   {
     switch (m_type)
@@ -52,6 +78,7 @@ namespace grino
       case TYPE_BOOL: return *m_bool_val ? "true" : "false";
       case TYPE_FUNCTION: return "<function>";
       case TYPE_REF: return "&" + std::to_string(*m_ref_val);
+      case TYPE_PROGRAM: return "<program>";
       default:
         std::cerr << "cannot stringify value "
                   << TypeTypeStr[m_type] << std::endl;
@@ -69,6 +96,7 @@ namespace grino
       case TYPE_BOOL: return *m_bool_val == *other.m_bool_val;
       case TYPE_INT: return *m_int_val == *other.m_int_val;
       case TYPE_REF: return *m_ref_val == *other.m_ref_val;
+      case TYPE_PROGRAM: return false;
 
       default:
         std::cerr << "cannot compare equality with value "

src/Value.hpp

@@ -8,6 +8,8 @@
 
 namespace grino
 {
+  class Program;
+
   class Value
   {
   public:
@@ -16,9 +18,14 @@ namespace grino
     static std::shared_ptr<Value> make_int(Loc const& loc, int val);
     static std::shared_ptr<Value> make_native_function(Loc const& loc,
                                                        native_t val);
+    static std::shared_ptr<Value> make_function(Loc const& loc,
+                                                std::shared_ptr<Program> val);
     static std::shared_ptr<Value> make_ref(Loc const& loc,
                                            size_t val);
 
+    static std::shared_ptr<Value> make_program(Loc const& loc,
+                                               std::shared_ptr<Program> val);
+
     explicit Value(Loc const& loc);
     virtual ~Value() = default;
 
@@ -28,6 +35,7 @@ namespace grino
     int as_int() const { return *m_int_val; }
     std::shared_ptr<Function> as_function() const { return m_function_val; }
     size_t as_ref() const { return *m_ref_val; }
+    std::shared_ptr<Program> as_program() const;
 
     std::string string() const;
     bool equals(Value const& other) const;
@@ -38,6 +46,7 @@ namespace grino
     std::optional<bool> m_bool_val;
     std::optional<int> m_int_val;
     std::shared_ptr<Function> m_function_val;
+    std::shared_ptr<Program> m_program_val;
     std::optional<size_t> m_ref_val;
   };
 }

src/main.cpp

@@ -36,14 +36,14 @@ void run(char** argv, bool debug_mode)
     }
 
   grino::SymTable sym_table {logger};
-  grino::VM vm {logger};
-  grino::Compiler compiler {logger, sym_table};
+  grino::Program program;
+  grino::VM vm {logger, program};
+  grino::Compiler compiler {logger};
 
   grino::Loader loader {vm, compiler, sym_table};
   loader.load_libraries();
 
-  grino::Program program;
-  compiler.compile(ast, program);
+  compiler.compile(ast, program, sym_table);
 
   if (debug_mode)
     {
@@ -51,7 +51,7 @@ void run(char** argv, bool debug_mode)
       std::cout << program.string() << std::endl;
     }
 
-  vm.run(program);
+  vm.run();
 
   if (debug_mode)
     {

src/opcodes.hpp

@@ -15,7 +15,8 @@
     G(OPCODE_BRF),                              \
     G(OPCODE_BR),                               \
     G(OPCODE_NOT),                              \
-    G(OPCODE_RET),
+    G(OPCODE_RET),                              \
+    G(OPCODE_MK_FUN),
 
 namespace grino
 {

src/types.hpp

@@ -8,7 +8,9 @@
     G(TYPE_BOOL),                               \
     G(TYPE_INT),                                \
     G(TYPE_FUNCTION),                           \
-    G(TYPE_REF)
+    G(TYPE_REF),                                \
+    G(TYPE_PROGRAM)
+
 
 namespace grino
 {

tests/Lexer.cpp

@@ -90,3 +90,12 @@ TEST_CASE_METHOD(LexerTest, "Lexer_int")
   test_next(lexer, "INT[-7]");
   test_end(lexer);
 }
+
+TEST_CASE_METHOD(LexerTest, "Lexer_lambda")
+{
+  grino::Lexer lexer {m_logger, "tests/lexer"};
+
+  lexer.scan(" -> ");
+  test_next(lexer, "LAMBDA");
+  test_end(lexer);
+}

tests/Parser.cpp

@@ -54,3 +54,23 @@ TEST_CASE_METHOD(ParserTest, "Parser_integer")
   test_parse("MODULE(FUNCALL(IDENT[hello],INT[2],INT[34]))",
              "(hello 2 34)");
 }
+
+TEST_CASE_METHOD(ParserTest, "Parser_lambda")
+{
+  test_parse("MODULE(LAMBDA(PARAMS,BODY))",
+             "(-> ())");
+
+  test_parse("MODULE(LAMBDA(PARAMS(IDENT[x]),BODY))",
+             "(-> (x))");
+
+  test_parse("MODULE(LAMBDA(PARAMS(IDENT[x],IDENT[y]),BODY(IDENT[y])))",
+             "(-> (x y) y)");
+
+  test_parse("MODULE(FUNCALL(LAMBDA(PARAMS("
+             "IDENT[x]"
+             "),BODY("
+             "IDENT[x]"
+             ")),INT[4]))",
+             "( (-> (x) x ) 4 )");
+
+}