Unified null and false.

doc/Literals.md

@@ -16,7 +16,9 @@ This page explains literals.
 
     boolean: 'true' | 'false' ;
 
-`null` and `false` are falsy. The other values are all truthy.
+`false` is an alias for `null`.
+The only falsy value is `null`. The other values are all truthy.
+`true` is the value that is just truthy.
 
 ## Integer Literals
 

doc/StackUsage.md

@@ -104,7 +104,7 @@
     NUL
         |
         |N
-    BOOLEAN
+    TRUE
         |
         |B
     INTEGER

doc/TermExpressions.md

@@ -10,7 +10,7 @@ See [PrimaryExpressions](PrimaryExpressions.md).
 
     unary: ('+' | '-' | '!' | '~')* primary ;
 
-Negate operator (`!`) returns `true` if the operand is falsy, returns `false` otherwise.
+Negate operator (`!`) returns `true` if the operand is `false` (`null`), returns `false` (`null`) otherwise.
 
 ## Multiplicative Expressions
 
@@ -28,7 +28,7 @@ Negate operator (`!`) returns `true` if the operand is falsy, returns `false` ot
 
     relational: shift (('<' | '>' | '<=' | '>=') shift)* ;
 
-Relational, equality, and identity operators return either `true` or `false`.
+Relational, equality, and identity operators return either `true` or `false` (`null`).
 
 ## Equality Expressions
 
@@ -42,7 +42,7 @@ Relational, equality, and identity operators return either `true` or `false`.
 
     and: identity ('&' identity)* ;
 
-Bitwise operators (`&`, `^`, and `|`) do bitwise operations if both the operands are integers, do boolean operations if both the operands are booleans, throws an exception otherwise.
+Bitwise operators (`&`, `^`, and `|`) do bitwise operations if both the operands are integers, do boolean operations if the left operand is boolean (`true`, `false`, or `null`), throws an exception otherwise.
 
 ## Xor Expressions
 
@@ -56,13 +56,13 @@ Bitwise operators (`&`, `^`, and `|`) do bitwise operations if both the operands
 
     and_also: or ('&&' or)* ;
 
-Evaluates the left operand, returns it if it is falsy, evaluates the right operand and returns it otherwise.
+Evaluates the left operand, returns it if it is `false` (`null`), evaluates the right operand and returns it otherwise.
 
 ## Or Else Expressions
 
     or_else: and_also ('||' and_also)* ;
 
-Evaluates the left operand, returns it if it is truthy, evaluates the right operand and returns it otherwise.
+Evaluates the left operand, returns it if it is not `false` (`null`), evaluates the right operand and returns it otherwise.
 
 ## Conditional Expressions
 

doc/WalkThrough.md

@@ -13,7 +13,7 @@ This document walks through xemmai language.
     "This is a string."
     null
     true
-    false
+    false # => null
 
 ## Variables
 

include/xemmai/ast.h

@@ -72,32 +72,22 @@ struct t_operand
 		e_tag__TEMPORARY
 	};
 
-	static inline const t_pvalue v_null{};
-	static inline const t_pvalue v_true{true};
-	static inline const t_pvalue v_false{false};
-
 	t_tag v_tag;
 	union
 	{
 		intptr_t v_integer;
 		double v_float;
-		const t_pvalue* v_value;
+		t_object* v_value;
 		size_t v_index;
 	};
 
-	t_operand(nullptr_t) : v_tag(e_tag__LITERAL), v_value(&v_null)
-	{
-	}
-	t_operand(bool a_value) : v_tag(e_tag__LITERAL), v_value(a_value ? &v_true : &v_false)
-	{
-	}
 	t_operand(intptr_t a_value) : v_tag(e_tag__INTEGER), v_integer(a_value)
 	{
 	}
 	t_operand(double a_value) : v_tag(e_tag__FLOAT), v_float(a_value)
 	{
 	}
-	t_operand(t_svalue& a_value) : v_tag(e_tag__LITERAL), v_value(reinterpret_cast<const t_pvalue*>(&a_value))
+	t_operand(t_object* a_value) : v_tag(e_tag__LITERAL), v_value(a_value)
 	{
 	}
 	t_operand() : v_tag(e_tag__TEMPORARY)
@@ -418,11 +408,16 @@ struct t_super : t_node
 	virtual t_operand f_emit(t_emit& a_emit, bool a_tail, bool a_operand, bool a_clear);
 };
 
-struct t_null : t_node
+struct t_boolean : t_node
 {
-	using t_node::t_node;
+	bool v_value;
+
+	t_boolean(const t_at& a_at, bool a_value = false) : t_node(a_at), v_value(a_value)
+	{
+	}
 	virtual t_operand f_emit(t_emit& a_emit, bool a_tail, bool a_operand, bool a_clear);
 };
+using t_null = t_boolean;
 
 template<typename T>
 struct t_literal : t_node
@@ -569,11 +564,6 @@ struct XEMMAI__LOCAL t_emit
 		v_code->v_instructions.push_back(reinterpret_cast<void*>(a_operand));
 		return *this;
 	}
-	t_emit& operator<<(bool a_operand)
-	{
-		v_code->v_instructions.push_back(reinterpret_cast<void*>(a_operand ? 1 : 0));
-		return *this;
-	}
 	t_emit& operator<<(double a_operand)
 	{
 		union
@@ -585,14 +575,9 @@ struct XEMMAI__LOCAL t_emit
 		for (size_t i = 0; i < sizeof(double) / sizeof(void*); ++i) v_code->v_instructions.push_back(v1[i]);
 		return *this;
 	}
-	t_emit& operator<<(const t_pvalue& a_operand)
+	t_emit& operator<<(t_object* a_operand)
 	{
-		v_code->v_instructions.push_back(const_cast<t_pvalue*>(&a_operand));
-		return *this;
-	}
-	t_emit& operator<<(t_svalue& a_operand)
-	{
-		v_code->v_instructions.push_back(&a_operand);
+		v_code->v_instructions.push_back(a_operand);
 		return *this;
 	}
 	t_emit& operator<<(t_label& a_label)
@@ -637,11 +622,6 @@ struct XEMMAI__LOCAL t_emit
 	}
 };
 
-template<>
-constexpr t_instruction t_emit::f_instruction_of<bool>()
-{
-	return e_instruction__BOOLEAN;
-}
 template<>
 constexpr t_instruction t_emit::f_instruction_of<intptr_t>()
 {
@@ -663,7 +643,7 @@ t_operand t_literal<T>::f_emit(t_emit& a_emit, bool a_tail, bool a_operand, bool
 	if (a_clear) return {};
 	if (a_tail) {
 		a_emit.f_emit_safe_point(this);
-		a_emit << static_cast<t_instruction>(t_emit::f_instruction_of<T>() + e_instruction__RETURN_BOOLEAN - e_instruction__BOOLEAN) << v_value;
+		a_emit << static_cast<t_instruction>(t_emit::f_instruction_of<T>() + e_instruction__RETURN_NUL - e_instruction__NUL) << v_value;
 	} else {
 		a_emit << t_emit::f_instruction_of<T>() << a_emit.v_stack << v_value;
 	}

include/xemmai/boolean.h

@@ -14,7 +14,7 @@ struct t_type_of<bool> : t_uninstantiatable<t_bears<bool>>
 	{
 		static bool f_as(auto&& a_object)
 		{
-			return a_object && (a_object.f_tag() != e_tag__BOOLEAN || a_object.f_boolean());
+			return a_object;
 		}
 		static bool f_is(t_object* a_object)
 		{
@@ -24,11 +24,7 @@ struct t_type_of<bool> : t_uninstantiatable<t_bears<bool>>
 
 	static t_object* f__string(bool a_self)
 	{
-		return t_string::f_instantiate(a_self ? L"true"sv : L"false"sv);
-	}
-	static intptr_t f__hash(bool a_self)
-	{
-		return a_self ? 1 : 0;
+		return t_string::f_instantiate(a_self ? L"true"sv : L"null"sv);
 	}
 	XEMMAI__LOCAL static void f_define();
 

include/xemmai/code.h

@@ -40,12 +40,12 @@ enum t_instruction
 	e_instruction__CLASS,
 	e_instruction__SUPER,
 	e_instruction__NUL,
-	e_instruction__BOOLEAN,
+	e_instruction__TRU,
 	e_instruction__INTEGER,
 	e_instruction__FLOAT,
 	e_instruction__INSTANCE,
 	e_instruction__RETURN_NUL,
-	e_instruction__RETURN_BOOLEAN,
+	e_instruction__RETURN_TRU,
 	e_instruction__RETURN_INTEGER,
 	e_instruction__RETURN_FLOAT,
 	e_instruction__RETURN_INSTANCE,

include/xemmai/fiber.h

@@ -265,7 +265,7 @@ inline t_pvalue t_value<T_tag>::f_##a_name() const\
 	auto p = static_cast<t_object*>(*this);\
 	switch (reinterpret_cast<uintptr_t>(p)) {\
 	case e_tag__NULL:\
-	case e_tag__BOOLEAN:\
+	case e_tag__TRUE:\
 		f_throw(L"not supported."sv);\
 	case e_tag__INTEGER:\
 		return a_operator(v_integer);\
@@ -287,7 +287,7 @@ inline t_pvalue t_value<T_tag>::f_complement() const
 	case e_tag__INTEGER:
 		return ~v_integer;
 	case e_tag__NULL:
-	case e_tag__BOOLEAN:
+	case e_tag__TRUE:
 	case e_tag__FLOAT:
 		f_throw(L"not supported."sv);
 	default:

include/xemmai/float.h

@@ -42,7 +42,7 @@ struct t_type_of<double> : t_derivable<t_bears<double>, t_derived_primitive<doub
 			if (!std::is_same_v<typename t_fundamental<T>::t_type, double>) return reinterpret_cast<uintptr_t>(a_object) >= e_tag__OBJECT && a_object->f_type()->f_derives<typename t_fundamental<T>::t_type>();
 			switch (reinterpret_cast<uintptr_t>(a_object)) {
 			case e_tag__NULL:
-			case e_tag__BOOLEAN:
+			case e_tag__TRUE:
 				return false;
 			case e_tag__INTEGER:
 			case e_tag__FLOAT:

include/xemmai/global.h

@@ -4,7 +4,6 @@
 #include "engine.h"
 #include "native.h"
 #include "method.h"
-#include "null.h"
 #include "list.h"
 #include "map.h"
 #include "bytes.h"
@@ -39,7 +38,6 @@ class t_global : public t_library
 	t_slot_of<t_type> v_type_advanced_lambda_shared;
 	t_slot_of<t_type> v_type_method;
 	t_slot_of<t_type> v_type_throwable;
-	t_slot_of<t_type> v_type_null;
 	t_slot_of<t_type> v_type_boolean;
 	t_slot_of<t_type> v_type_integer;
 	t_slot_of<t_type> v_type_float;
@@ -216,7 +214,6 @@ XEMMAI__LIBRARY__TYPE_AS(t_global, t_advanced_lambda<t_lambda>, advanced_lambda)
 XEMMAI__LIBRARY__TYPE_AS(t_global, t_advanced_lambda<t_lambda_shared>, advanced_lambda_shared)
 XEMMAI__LIBRARY__TYPE(t_global, method)
 XEMMAI__LIBRARY__TYPE(t_global, throwable)
-XEMMAI__LIBRARY__TYPE_AS(t_global, std::nullptr_t, null)
 XEMMAI__LIBRARY__TYPE_AS(t_global, bool, boolean)
 XEMMAI__LIBRARY__TYPE_AS(t_global, intptr_t, integer)
 XEMMAI__LIBRARY__TYPE_AS(t_global, double, float)
@@ -244,8 +241,7 @@ XEMMAI__PORTABLE__ALWAYS_INLINE inline t_type* t_value<T_tag>::f_type() const
 	auto p = static_cast<t_object*>(*this);
 	switch (reinterpret_cast<uintptr_t>(p)) {
 	case e_tag__NULL:
-		return f_global()->f_type<std::nullptr_t>();
-	case e_tag__BOOLEAN:
+	case e_tag__TRUE:
 		return f_global()->f_type<bool>();
 	case e_tag__INTEGER:
 		return f_global()->f_type<intptr_t>();
@@ -281,9 +277,8 @@ inline t_pvalue t_value<T_tag>::f_##a_name() const\
 	auto p = static_cast<t_object*>(*this);\
 	switch (reinterpret_cast<uintptr_t>(p)) {\
 	case e_tag__NULL:\
-		return t_type_of<std::nullptr_t>::f__##a_name(*this);\
-	case e_tag__BOOLEAN:\
-		return t_type_of<bool>::f__##a_name(v_boolean);\
+	case e_tag__TRUE:\
+		return t_type_of<bool>::f__##a_name(*this);\
 	case e_tag__INTEGER:\
 		return t_type_of<intptr_t>::f__##a_name(v_integer);\
 	case e_tag__FLOAT:\
@@ -315,7 +310,7 @@ inline t_pvalue t_value<T_tag>::f_##a_name(const t_pvalue& a_value) const\
 	auto p = static_cast<t_object*>(*this);\
 	switch (reinterpret_cast<uintptr_t>(p)) {\
 	case e_tag__NULL:\
-	case e_tag__BOOLEAN:\
+	case e_tag__TRUE:\
 		f_throw(L"not supported."sv);\
 	case e_tag__INTEGER:\
 		return t_type_of<intptr_t>::f__##a_name(v_integer, a_value);\
@@ -336,7 +331,7 @@ inline t_pvalue t_value<T_tag>::f_##a_name(const t_pvalue& a_value) const\
 		f_check<intptr_t>(a_value, L"argument0");\
 		return static_cast<uintptr_t>(v_integer) a_operator f_as<intptr_t>(a_value);\
 	case e_tag__NULL:\
-	case e_tag__BOOLEAN:\
+	case e_tag__TRUE:\
 	case e_tag__FLOAT:\
 		f_throw(L"not supported."sv);\
 	default:\
@@ -350,9 +345,8 @@ inline t_pvalue t_value<T_tag>::f_##a_name(const t_pvalue& a_value) const\
 	auto p = static_cast<t_object*>(*this);\
 	switch (reinterpret_cast<uintptr_t>(p)) {\
 	case e_tag__NULL:\
+	case e_tag__TRUE:\
 		return a_operator(p == a_value.v_p);\
-	case e_tag__BOOLEAN:\
-		return a_operator(p == a_value.v_p && v_boolean == a_value.v_boolean);\
 	case e_tag__INTEGER:\
 		return t_type_of<intptr_t>::f__##a_name(v_integer, a_value);\
 	case e_tag__FLOAT:\
@@ -367,13 +361,12 @@ inline t_pvalue t_value<T_tag>::f_##a_name(const t_pvalue& a_value) const\
 {\
 	auto p = static_cast<t_object*>(*this);\
 	switch (reinterpret_cast<uintptr_t>(p)) {\
-	case e_tag__BOOLEAN:\
-		if (a_value.f_tag() != e_tag__BOOLEAN) [[unlikely]] f_throw_type_error<bool>(L"argument0");\
-		return v_boolean a_operator a_value.v_boolean;\
+	case e_tag__NULL:\
+	case e_tag__TRUE:\
+		return static_cast<bool>(static_cast<bool>(p) a_operator f_as<bool>(a_value));\
 	case e_tag__INTEGER:\
 		f_check<intptr_t>(a_value, L"argument0");\
 		return v_integer a_operator f_as<intptr_t>(a_value);\
-	case e_tag__NULL:\
 	case e_tag__FLOAT:\
 		f_throw(L"not supported."sv);\
 	default:\

include/xemmai/integer.h

@@ -38,7 +38,7 @@ struct t_type_of<intptr_t> : t_derivable<t_bears<intptr_t>, t_derived_primitive<
 			case e_tag__INTEGER:
 				return true;
 			case e_tag__NULL:
-			case e_tag__BOOLEAN:
+			case e_tag__TRUE:
 			case e_tag__FLOAT:
 				return false;
 			default:

include/xemmai/module.h

@@ -42,20 +42,19 @@ struct t_module
 struct t_script : t_module::t_body
 {
 	std::wstring v_path;
-	std::deque<t_svalue> v_slots;
+	std::deque<t_slot> v_slots;
 	std::mutex v_mutex;
 
 	t_script(std::wstring_view a_path) : v_path(a_path)
 	{
 	}
 	virtual void f_scan(t_scan a_scan);
-	t_svalue& f_slot(t_object* a_p)
+	t_object* f_slot(t_object* a_p)
 	{
 		v_mutex.lock();
 		auto& p = v_slots.emplace_back();
 		v_mutex.unlock();
-		p = a_p;
-		return p;
+		return p = a_p;
 	}
 };
 

include/xemmai/object.h

@@ -356,7 +356,7 @@ struct t_type::t_cast<T*>
 		switch (reinterpret_cast<uintptr_t>(a_object)) {
 		case e_tag__NULL:
 			return true;
-		case e_tag__BOOLEAN:
+		case e_tag__TRUE:
 		case e_tag__INTEGER:
 		case e_tag__FLOAT:
 			return false;