Refactor as Rust workspace

wasm/src/backend/ast/data.rs

@@ -0,0 +1,413 @@
+use std::ops::Range;
+
+use parity_wasm::elements::BrTableData;
+
+use crate::backend::visitor::data::Visitor;
+
+use super::operation::{BinOp, Load, Store, UnOp};
+
+#[derive(Clone)]
+pub struct Select {
+	pub cond: Box<Expression>,
+	pub a: Box<Expression>,
+	pub b: Box<Expression>,
+}
+
+impl Select {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_select(self);
+
+		self.cond.accept(visitor);
+		self.a.accept(visitor);
+		self.b.accept(visitor);
+	}
+}
+
+#[derive(Clone)]
+pub struct GetLocal {
+	pub var: u32,
+}
+
+impl GetLocal {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_get_local(self);
+	}
+}
+
+#[derive(Clone)]
+pub struct GetGlobal {
+	pub var: u32,
+}
+
+impl GetGlobal {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_get_global(self);
+	}
+}
+
+#[derive(Clone)]
+pub struct AnyLoad {
+	pub op: Load,
+	pub offset: u32,
+	pub pointer: Box<Expression>,
+}
+
+impl AnyLoad {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_any_load(self);
+
+		self.pointer.accept(visitor);
+	}
+}
+
+#[derive(Clone)]
+pub struct MemorySize {
+	pub memory: u8,
+}
+
+impl MemorySize {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_memory_size(self);
+	}
+}
+
+#[derive(Clone)]
+pub struct MemoryGrow {
+	pub memory: u8,
+	pub value: Box<Expression>,
+}
+
+impl MemoryGrow {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_memory_grow(self);
+
+		self.value.accept(visitor);
+	}
+}
+
+#[derive(Clone, Copy)]
+pub enum Value {
+	I32(i32),
+	I64(i64),
+	F32(f32),
+	F64(f64),
+}
+
+impl Value {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_value(self);
+	}
+}
+
+#[derive(Clone)]
+pub struct AnyUnOp {
+	pub op: UnOp,
+	pub rhs: Box<Expression>,
+}
+
+impl AnyUnOp {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_any_unop(self);
+
+		self.rhs.accept(visitor);
+	}
+}
+
+#[derive(Clone)]
+pub struct AnyBinOp {
+	pub op: BinOp,
+	pub lhs: Box<Expression>,
+	pub rhs: Box<Expression>,
+}
+
+impl AnyBinOp {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_any_binop(self);
+
+		self.lhs.accept(visitor);
+		self.rhs.accept(visitor);
+	}
+}
+
+#[derive(Clone)]
+pub enum Expression {
+	Recall(usize),
+	Select(Select),
+	GetLocal(GetLocal),
+	GetGlobal(GetGlobal),
+	AnyLoad(AnyLoad),
+	MemorySize(MemorySize),
+	MemoryGrow(MemoryGrow),
+	Value(Value),
+	AnyUnOp(AnyUnOp),
+	AnyBinOp(AnyBinOp),
+}
+
+impl Expression {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_expression(self);
+
+		match self {
+			Expression::Recall(v) => visitor.visit_recall(*v),
+			Expression::Select(v) => v.accept(visitor),
+			Expression::GetLocal(v) => v.accept(visitor),
+			Expression::GetGlobal(v) => v.accept(visitor),
+			Expression::AnyLoad(v) => v.accept(visitor),
+			Expression::MemorySize(v) => v.accept(visitor),
+			Expression::MemoryGrow(v) => v.accept(visitor),
+			Expression::Value(v) => v.accept(visitor),
+			Expression::AnyUnOp(v) => v.accept(visitor),
+			Expression::AnyBinOp(v) => v.accept(visitor),
+		}
+	}
+
+	pub fn is_recalling(&self, wanted: usize) -> bool {
+		match *self {
+			Expression::Recall(v) => v == wanted,
+			_ => false,
+		}
+	}
+}
+
+pub struct Memorize {
+	pub var: usize,
+	pub value: Expression,
+}
+
+impl Memorize {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_memorize(self);
+
+		self.value.accept(visitor);
+	}
+}
+
+pub struct Forward {
+	pub body: Vec<Statement>,
+}
+
+impl Forward {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_forward(self);
+
+		for v in &self.body {
+			v.accept(visitor);
+		}
+	}
+}
+
+pub struct Backward {
+	pub body: Vec<Statement>,
+}
+
+impl Backward {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_backward(self);
+
+		for v in &self.body {
+			v.accept(visitor);
+		}
+	}
+}
+
+pub struct If {
+	pub cond: Expression,
+	pub truthy: Vec<Statement>,
+	pub falsey: Option<Vec<Statement>>,
+}
+
+impl If {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_if(self);
+
+		self.cond.accept(visitor);
+
+		for v in &self.truthy {
+			v.accept(visitor);
+		}
+
+		if let Some(v) = &self.falsey {
+			for v in v {
+				v.accept(visitor);
+			}
+		}
+	}
+}
+
+pub struct Br {
+	pub target: u32,
+}
+
+impl Br {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_br(self);
+	}
+}
+
+pub struct BrIf {
+	pub cond: Expression,
+	pub target: u32,
+}
+
+impl BrIf {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_br_if(self);
+
+		self.cond.accept(visitor);
+	}
+}
+
+pub struct BrTable {
+	pub cond: Expression,
+	pub data: BrTableData,
+}
+
+impl BrTable {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_br_table(self);
+
+		self.cond.accept(visitor);
+	}
+}
+
+pub struct Return {
+	pub list: Vec<Expression>,
+}
+
+impl Return {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_return(self);
+
+		for v in &self.list {
+			v.accept(visitor);
+		}
+	}
+}
+
+pub struct Call {
+	pub func: u32,
+	pub result: Range<u32>,
+	pub param_list: Vec<Expression>,
+}
+
+impl Call {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_call(self);
+
+		for v in &self.param_list {
+			v.accept(visitor);
+		}
+	}
+}
+
+pub struct CallIndirect {
+	pub table: u8,
+	pub index: Expression,
+	pub result: Range<u32>,
+	pub param_list: Vec<Expression>,
+}
+
+impl CallIndirect {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_call_indirect(self);
+
+		self.index.accept(visitor);
+
+		for v in &self.param_list {
+			v.accept(visitor);
+		}
+	}
+}
+
+pub struct SetLocal {
+	pub var: u32,
+	pub value: Expression,
+}
+
+impl SetLocal {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_set_local(self);
+
+		self.value.accept(visitor);
+	}
+}
+
+pub struct SetGlobal {
+	pub var: u32,
+	pub value: Expression,
+}
+
+impl SetGlobal {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_set_global(self);
+
+		self.value.accept(visitor);
+	}
+}
+
+pub struct AnyStore {
+	pub op: Store,
+	pub offset: u32,
+	pub pointer: Expression,
+	pub value: Expression,
+}
+
+impl AnyStore {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		visitor.visit_any_store(self);
+
+		self.pointer.accept(visitor);
+		self.value.accept(visitor);
+	}
+}
+
+pub enum Statement {
+	Unreachable,
+	Memorize(Memorize),
+	Forward(Forward),
+	Backward(Backward),
+	If(If),
+	Br(Br),
+	BrIf(BrIf),
+	BrTable(BrTable),
+	Return(Return),
+	Call(Call),
+	CallIndirect(CallIndirect),
+	SetLocal(SetLocal),
+	SetGlobal(SetGlobal),
+	AnyStore(AnyStore),
+}
+
+impl Statement {
+	fn accept<V: Visitor>(&self, visitor: &mut V) {
+		match self {
+			Statement::Unreachable => visitor.visit_unreachable(),
+			Statement::Memorize(v) => v.accept(visitor),
+			Statement::Forward(v) => v.accept(visitor),
+			Statement::Backward(v) => v.accept(visitor),
+			Statement::If(v) => v.accept(visitor),
+			Statement::Br(v) => v.accept(visitor),
+			Statement::BrIf(v) => v.accept(visitor),
+			Statement::BrTable(v) => v.accept(visitor),
+			Statement::Return(v) => v.accept(visitor),
+			Statement::Call(v) => v.accept(visitor),
+			Statement::CallIndirect(v) => v.accept(visitor),
+			Statement::SetLocal(v) => v.accept(visitor),
+			Statement::SetGlobal(v) => v.accept(visitor),
+			Statement::AnyStore(v) => v.accept(visitor),
+		}
+	}
+}
+
+pub struct Function {
+	pub num_param: u32,
+	pub num_local: u32,
+	pub num_stack: u32,
+	pub body: Forward,
+}
+
+impl Function {
+	pub fn accept<V: Visitor>(&self, visitor: &mut V) {
+		self.body.accept(visitor);
+	}
+}

wasm/src/backend/ast/mod.rs

@@ -0,0 +1,3 @@
+pub mod data;
+mod operation;
+pub mod transformer;

wasm/src/backend/ast/operation.rs

@@ -0,0 +1,503 @@
+use std::convert::TryFrom;
+
+use parity_wasm::elements::Instruction;
+
+#[allow(non_camel_case_types)]
+#[derive(Clone, Copy)]
+pub enum Load {
+	I32,
+	I64,
+	F32,
+	F64,
+	I32_I8,
+	I32_U8,
+	I32_I16,
+	I32_U16,
+	I64_I8,
+	I64_U8,
+	I64_I16,
+	I64_U16,
+	I64_I32,
+	I64_U32,
+}
+
+impl Load {
+	pub fn as_name(self) -> &'static str {
+		match self {
+			Self::I32 => "i32",
+			Self::I64 => "i64",
+			Self::F32 => "f32",
+			Self::F64 => "f64",
+			Self::I32_I8 => "i32_i8",
+			Self::I32_U8 => "i32_u8",
+			Self::I32_I16 => "i32_i16",
+			Self::I32_U16 => "i32_u16",
+			Self::I64_I8 => "i64_i8",
+			Self::I64_U8 => "i64_u8",
+			Self::I64_I16 => "i64_i16",
+			Self::I64_U16 => "i64_u16",
+			Self::I64_I32 => "i64_i32",
+			Self::I64_U32 => "i64_u32",
+		}
+	}
+}
+
+impl TryFrom<&Instruction> for Load {
+	type Error = ();
+
+	fn try_from(inst: &Instruction) -> Result<Self, Self::Error> {
+		let result = match inst {
+			Instruction::I32Load(_, _) => Self::I32,
+			Instruction::I64Load(_, _) => Self::I64,
+			Instruction::F32Load(_, _) => Self::F32,
+			Instruction::F64Load(_, _) => Self::F64,
+			Instruction::I32Load8S(_, _) => Self::I32_I8,
+			Instruction::I32Load8U(_, _) => Self::I32_U8,
+			Instruction::I32Load16S(_, _) => Self::I32_I16,
+			Instruction::I32Load16U(_, _) => Self::I32_U16,
+			Instruction::I64Load8S(_, _) => Self::I64_I8,
+			Instruction::I64Load8U(_, _) => Self::I64_U8,
+			Instruction::I64Load16S(_, _) => Self::I64_I16,
+			Instruction::I64Load16U(_, _) => Self::I64_U16,
+			Instruction::I64Load32S(_, _) => Self::I64_I32,
+			Instruction::I64Load32U(_, _) => Self::I64_U32,
+			_ => return Err(()),
+		};
+
+		Ok(result)
+	}
+}
+
+#[allow(non_camel_case_types)]
+#[derive(Clone, Copy)]
+pub enum Store {
+	I32,
+	I64,
+	F32,
+	F64,
+	I32_N8,
+	I32_N16,
+	I64_N8,
+	I64_N16,
+	I64_N32,
+}
+
+impl Store {
+	pub fn as_name(self) -> &'static str {
+		match self {
+			Self::I32 => "i32",
+			Self::I64 => "i64",
+			Self::F32 => "f32",
+			Self::F64 => "f64",
+			Self::I32_N8 => "i32_n8",
+			Self::I32_N16 => "i32_n16",
+			Self::I64_N8 => "i64_n8",
+			Self::I64_N16 => "i64_n16",
+			Self::I64_N32 => "i64_n32",
+		}
+	}
+}
+
+impl TryFrom<&Instruction> for Store {
+	type Error = ();
+
+	fn try_from(inst: &Instruction) -> Result<Self, Self::Error> {
+		let result = match inst {
+			Instruction::I32Store(_, _) => Self::I32,
+			Instruction::I64Store(_, _) => Self::I64,
+			Instruction::F32Store(_, _) => Self::F32,
+			Instruction::F64Store(_, _) => Self::F64,
+			Instruction::I32Store8(_, _) => Self::I32_N8,
+			Instruction::I32Store16(_, _) => Self::I32_N16,
+			Instruction::I64Store8(_, _) => Self::I64_N8,
+			Instruction::I64Store16(_, _) => Self::I64_N16,
+			Instruction::I64Store32(_, _) => Self::I64_N32,
+			_ => return Err(()),
+		};
+
+		Ok(result)
+	}
+}
+
+// Order of mnemonics is:
+// operation_result_parameter
+#[allow(non_camel_case_types)]
+#[derive(Clone, Copy)]
+pub enum UnOp {
+	Eqz_I32,
+	Eqz_I64,
+	Clz_I32,
+	Ctz_I32,
+	Popcnt_I32,
+	Clz_I64,
+	Ctz_I64,
+	Popcnt_I64,
+	Abs_FN,
+	Neg_FN,
+	Ceil_FN,
+	Floor_FN,
+	Trunc_FN,
+	Nearest_FN,
+	Sqrt_FN,
+	Wrap_I32_I64,
+	Trunc_I32_F32,
+	Trunc_U32_F32,
+	Trunc_I32_F64,
+	Trunc_U32_F64,
+	Extend_I64_I32,
+	Extend_U64_I32,
+	Trunc_I64_F32,
+	Trunc_U64_F32,
+	Trunc_I64_F64,
+	Trunc_U64_F64,
+	Convert_F32_I32,
+	Convert_F32_U32,
+	Convert_F32_I64,
+	Convert_F32_U64,
+	Demote_F32_F64,
+	Convert_F64_I32,
+	Convert_F64_U32,
+	Convert_F64_I64,
+	Convert_F64_U64,
+	Promote_F64_F32,
+	Reinterpret_I32_F32,
+	Reinterpret_I64_F64,
+	Reinterpret_F32_I32,
+	Reinterpret_F64_I64,
+}
+
+impl UnOp {
+	pub fn as_operator(self) -> Option<&'static str> {
+		let op = match self {
+			Self::Neg_FN => "-",
+			_ => return None,
+		};
+
+		Some(op)
+	}
+
+	pub fn as_name(self) -> (&'static str, &'static str) {
+		match self {
+			Self::Eqz_I32 => ("eqz", "i32"),
+			Self::Eqz_I64 => ("eqz", "i64"),
+			Self::Clz_I32 => ("clz", "i32"),
+			Self::Ctz_I32 => ("ctz", "i32"),
+			Self::Popcnt_I32 => ("popcnt", "i32"),
+			Self::Clz_I64 => ("clz", "i64"),
+			Self::Ctz_I64 => ("ctz", "i64"),
+			Self::Popcnt_I64 => ("popcnt", "i64"),
+			Self::Abs_FN => ("math", "abs"),
+			Self::Neg_FN => ("neg", "num"),
+			Self::Ceil_FN => ("math", "ceil"),
+			Self::Floor_FN => ("math", "floor"),
+			Self::Trunc_FN => ("trunc", "num"),
+			Self::Nearest_FN => ("nearest", "num"),
+			Self::Sqrt_FN => ("math", "sqrt"),
+			Self::Wrap_I32_I64 => ("wrap", "i32_i64"),
+			Self::Trunc_I32_F32 => ("trunc", "i32_f32"),
+			Self::Trunc_U32_F32 => ("trunc", "u32_f32"),
+			Self::Trunc_I32_F64 => ("trunc", "i32_f64"),
+			Self::Trunc_U32_F64 => ("trunc", "u32_f64"),
+			Self::Extend_I64_I32 => ("extend", "i64_i32"),
+			Self::Extend_U64_I32 => ("extend", "u64_i32"),
+			Self::Trunc_I64_F32 => ("trunc", "i64_f32"),
+			Self::Trunc_U64_F32 => ("trunc", "u64_f32"),
+			Self::Trunc_I64_F64 => ("trunc", "i64_f64"),
+			Self::Trunc_U64_F64 => ("trunc", "u64_f64"),
+			Self::Convert_F32_I32 => ("convert", "f32_i32"),
+			Self::Convert_F32_U32 => ("convert", "f32_u32"),
+			Self::Convert_F32_I64 => ("convert", "f32_i64"),
+			Self::Convert_F32_U64 => ("convert", "f32_u64"),
+			Self::Demote_F32_F64 => ("demote", "f32_f64"),
+			Self::Convert_F64_I32 => ("convert", "f64_i32"),
+			Self::Convert_F64_U32 => ("convert", "f64_u32"),
+			Self::Convert_F64_I64 => ("convert", "f64_i64"),
+			Self::Convert_F64_U64 => ("convert", "f64_u64"),
+			Self::Promote_F64_F32 => ("promote", "f64_f32"),
+			Self::Reinterpret_I32_F32 => ("reinterpret", "i32_f32"),
+			Self::Reinterpret_I64_F64 => ("reinterpret", "i64_f64"),
+			Self::Reinterpret_F32_I32 => ("reinterpret", "f32_i32"),
+			Self::Reinterpret_F64_I64 => ("reinterpret", "f64_i64"),
+		}
+	}
+}
+
+impl TryFrom<&Instruction> for UnOp {
+	type Error = ();
+
+	fn try_from(inst: &Instruction) -> Result<Self, Self::Error> {
+		let result = match inst {
+			Instruction::I32Eqz => Self::Eqz_I32,
+			Instruction::I64Eqz => Self::Eqz_I64,
+			Instruction::I32Clz => Self::Clz_I32,
+			Instruction::I32Ctz => Self::Ctz_I32,
+			Instruction::I32Popcnt => Self::Popcnt_I32,
+			Instruction::I64Clz => Self::Clz_I64,
+			Instruction::I64Ctz => Self::Ctz_I64,
+			Instruction::I64Popcnt => Self::Popcnt_I64,
+			Instruction::F32Abs | Instruction::F64Abs => Self::Abs_FN,
+			Instruction::F32Neg | Instruction::F64Neg => Self::Neg_FN,
+			Instruction::F32Ceil | Instruction::F64Ceil => Self::Ceil_FN,
+			Instruction::F32Floor | Instruction::F64Floor => Self::Floor_FN,
+			Instruction::F32Trunc | Instruction::F64Trunc => Self::Trunc_FN,
+			Instruction::F32Nearest | Instruction::F64Nearest => Self::Nearest_FN,
+			Instruction::F32Sqrt | Instruction::F64Sqrt => Self::Sqrt_FN,
+			Instruction::I32WrapI64 => Self::Wrap_I32_I64,
+			Instruction::I32TruncSF32 => Self::Trunc_I32_F32,
+			Instruction::I32TruncUF32 => Self::Trunc_U32_F32,
+			Instruction::I32TruncSF64 => Self::Trunc_I32_F64,
+			Instruction::I32TruncUF64 => Self::Trunc_U32_F64,
+			Instruction::I64ExtendSI32 => Self::Extend_I64_I32,
+			Instruction::I64ExtendUI32 => Self::Extend_U64_I32,
+			Instruction::I64TruncSF32 => Self::Trunc_I64_F32,
+			Instruction::I64TruncUF32 => Self::Trunc_U64_F32,
+			Instruction::I64TruncSF64 => Self::Trunc_I64_F64,
+			Instruction::I64TruncUF64 => Self::Trunc_U64_F64,
+			Instruction::F32ConvertSI32 => Self::Convert_F32_I32,
+			Instruction::F32ConvertUI32 => Self::Convert_F32_U32,
+			Instruction::F32ConvertSI64 => Self::Convert_F32_I64,
+			Instruction::F32ConvertUI64 => Self::Convert_F32_U64,
+			Instruction::F32DemoteF64 => Self::Demote_F32_F64,
+			Instruction::F64ConvertSI32 => Self::Convert_F64_I32,
+			Instruction::F64ConvertUI32 => Self::Convert_F64_U32,
+			Instruction::F64ConvertSI64 => Self::Convert_F64_I64,
+			Instruction::F64ConvertUI64 => Self::Convert_F64_U64,
+			Instruction::F64PromoteF32 => Self::Promote_F64_F32,
+			Instruction::I32ReinterpretF32 => Self::Reinterpret_I32_F32,
+			Instruction::I64ReinterpretF64 => Self::Reinterpret_I64_F64,
+			Instruction::F32ReinterpretI32 => Self::Reinterpret_F32_I32,
+			Instruction::F64ReinterpretI64 => Self::Reinterpret_F64_I64,
+			_ => return Err(()),
+		};
+
+		Ok(result)
+	}
+}
+
+#[allow(non_camel_case_types)]
+#[derive(Clone, Copy)]
+pub enum BinOp {
+	Eq_I32,
+	Ne_I32,
+	LtS_I32,
+	LtU_I32,
+	GtS_I32,
+	GtU_I32,
+	LeS_I32,
+	LeU_I32,
+	GeS_I32,
+	GeU_I32,
+	Eq_I64,
+	Ne_I64,
+	LtS_I64,
+	LtU_I64,
+	GtS_I64,
+	GtU_I64,
+	LeS_I64,
+	LeU_I64,
+	GeS_I64,
+	GeU_I64,
+	Add_I32,
+	Sub_I32,
+	Mul_I32,
+	DivS_I32,
+	DivU_I32,
+	RemS_I32,
+	RemU_I32,
+	And_I32,
+	Or_I32,
+	Xor_I32,
+	Shl_I32,
+	ShrS_I32,
+	ShrU_I32,
+	Rotl_I32,
+	Rotr_I32,
+	Add_I64,
+	Sub_I64,
+	Mul_I64,
+	DivS_I64,
+	DivU_I64,
+	RemS_I64,
+	RemU_I64,
+	And_I64,
+	Or_I64,
+	Xor_I64,
+	Shl_I64,
+	ShrS_I64,
+	ShrU_I64,
+	Rotl_I64,
+	Rotr_I64,
+	Eq_FN,
+	Ne_FN,
+	Lt_FN,
+	Gt_FN,
+	Le_FN,
+	Ge_FN,
+	Add_FN,
+	Sub_FN,
+	Mul_FN,
+	Div_FN,
+	Min_FN,
+	Max_FN,
+	Copysign_FN,
+}
+
+impl BinOp {
+	pub fn as_operator(self) -> Option<&'static str> {
+		let op = match self {
+			Self::Add_FN => "+",
+			Self::Sub_FN => "-",
+			Self::Mul_FN => "*",
+			Self::Div_FN => "/",
+			Self::RemS_I32 | Self::RemU_I32 | Self::RemS_I64 | Self::RemU_I64 => "%",
+			_ => return None,
+		};
+
+		Some(op)
+	}
+
+	pub fn as_name(self) -> (&'static str, &'static str) {
+		match self {
+			Self::Eq_I32 => ("eq", "i32"),
+			Self::Ne_I32 => ("ne", "i32"),
+			Self::LtS_I32 => ("lt", "i32"),
+			Self::LtU_I32 => ("lt", "u32"),
+			Self::GtS_I32 => ("gt", "i32"),
+			Self::GtU_I32 => ("gt", "u32"),
+			Self::LeS_I32 => ("le", "i32"),
+			Self::LeU_I32 => ("le", "u32"),
+			Self::GeS_I32 => ("ge", "i32"),
+			Self::GeU_I32 => ("ge", "u32"),
+			Self::Eq_I64 => ("eq", "i64"),
+			Self::Ne_I64 => ("ne", "i64"),
+			Self::LtS_I64 => ("lt", "i64"),
+			Self::LtU_I64 => ("lt", "u64"),
+			Self::GtS_I64 => ("gt", "i64"),
+			Self::GtU_I64 => ("gt", "u64"),
+			Self::LeS_I64 => ("le", "i64"),
+			Self::LeU_I64 => ("le", "u64"),
+			Self::GeS_I64 => ("ge", "i64"),
+			Self::GeU_I64 => ("ge", "u64"),
+			Self::Add_I32 => ("add", "i32"),
+			Self::Sub_I32 => ("sub", "i32"),
+			Self::Mul_I32 => ("mul", "i32"),
+			Self::DivS_I32 => ("div", "i32"),
+			Self::DivU_I32 => ("div", "u32"),
+			Self::RemS_I32 => ("rem", "i32"),
+			Self::RemU_I32 => ("rem", "u32"),
+			Self::And_I32 => ("band", "i32"),
+			Self::Or_I32 => ("bor", "i32"),
+			Self::Xor_I32 => ("bxor", "i32"),
+			Self::Shl_I32 => ("shl", "i32"),
+			Self::ShrS_I32 => ("shr", "i32"),
+			Self::ShrU_I32 => ("shr", "u32"),
+			Self::Rotl_I32 => ("rotl", "i32"),
+			Self::Rotr_I32 => ("rotr", "i32"),
+			Self::Add_I64 => ("add", "i64"),
+			Self::Sub_I64 => ("sub", "i64"),
+			Self::Mul_I64 => ("mul", "i64"),
+			Self::DivS_I64 => ("div", "i64"),
+			Self::DivU_I64 => ("div", "u64"),
+			Self::RemS_I64 => ("rem", "i64"),
+			Self::RemU_I64 => ("rem", "u64"),
+			Self::And_I64 => ("band", "i64"),
+			Self::Or_I64 => ("bor", "i64"),
+			Self::Xor_I64 => ("bxor", "i64"),
+			Self::Shl_I64 => ("shl", "i64"),
+			Self::ShrS_I64 => ("shr", "i64"),
+			Self::ShrU_I64 => ("shr", "u64"),
+			Self::Rotl_I64 => ("rotl", "i64"),
+			Self::Rotr_I64 => ("rotr", "i64"),
+			Self::Eq_FN => ("eq", "num"),
+			Self::Ne_FN => ("ne", "num"),
+			Self::Lt_FN => ("lt", "num"),
+			Self::Gt_FN => ("gt", "num"),
+			Self::Le_FN => ("le", "num"),
+			Self::Ge_FN => ("ge", "num"),
+			Self::Add_FN => ("add", "num"),
+			Self::Sub_FN => ("sub", "num"),
+			Self::Mul_FN => ("mul", "num"),
+			Self::Div_FN => ("div", "num"),
+			Self::Min_FN => ("math", "min"),
+			Self::Max_FN => ("math", "max"),
+			Self::Copysign_FN => ("copysign", "num"),
+		}
+	}
+}
+
+impl TryFrom<&Instruction> for BinOp {
+	type Error = ();
+
+	fn try_from(inst: &Instruction) -> Result<Self, Self::Error> {
+		let result = match inst {
+			Instruction::I32Eq => Self::Eq_I32,
+			Instruction::I32Ne => Self::Ne_I32,
+			Instruction::I32LtS => Self::LtS_I32,
+			Instruction::I32LtU => Self::LtU_I32,
+			Instruction::I32GtS => Self::GtS_I32,
+			Instruction::I32GtU => Self::GtU_I32,
+			Instruction::I32LeS => Self::LeS_I32,
+			Instruction::I32LeU => Self::LeU_I32,
+			Instruction::I32GeS => Self::GeS_I32,
+			Instruction::I32GeU => Self::GeU_I32,
+			Instruction::I64Eq => Self::Eq_I64,
+			Instruction::I64Ne => Self::Ne_I64,
+			Instruction::I64LtS => Self::LtS_I64,
+			Instruction::I64LtU => Self::LtU_I64,
+			Instruction::I64GtS => Self::GtS_I64,
+			Instruction::I64GtU => Self::GtU_I64,
+			Instruction::I64LeS => Self::LeS_I64,
+			Instruction::I64LeU => Self::LeU_I64,
+			Instruction::I64GeS => Self::GeS_I64,
+			Instruction::I64GeU => Self::GeU_I64,
+			Instruction::I32Add => Self::Add_I32,
+			Instruction::I32Sub => Self::Sub_I32,
+			Instruction::I32Mul => Self::Mul_I32,
+			Instruction::I32DivS => Self::DivS_I32,
+			Instruction::I32DivU => Self::DivU_I32,
+			Instruction::I32RemS => Self::RemS_I32,
+			Instruction::I32RemU => Self::RemU_I32,
+			Instruction::I32And => Self::And_I32,
+			Instruction::I32Or => Self::Or_I32,
+			Instruction::I32Xor => Self::Xor_I32,
+			Instruction::I32Shl => Self::Shl_I32,
+			Instruction::I32ShrS => Self::ShrS_I32,
+			Instruction::I32ShrU => Self::ShrU_I32,
+			Instruction::I32Rotl => Self::Rotl_I32,
+			Instruction::I32Rotr => Self::Rotr_I32,
+			Instruction::I64Add => Self::Add_I64,
+			Instruction::I64Sub => Self::Sub_I64,
+			Instruction::I64Mul => Self::Mul_I64,
+			Instruction::I64DivS => Self::DivS_I64,
+			Instruction::I64DivU => Self::DivU_I64,
+			Instruction::I64RemS => Self::RemS_I64,
+			Instruction::I64RemU => Self::RemU_I64,
+			Instruction::I64And => Self::And_I64,
+			Instruction::I64Or => Self::Or_I64,
+			Instruction::I64Xor => Self::Xor_I64,
+			Instruction::I64Shl => Self::Shl_I64,
+			Instruction::I64ShrS => Self::ShrS_I64,
+			Instruction::I64ShrU => Self::ShrU_I64,
+			Instruction::I64Rotl => Self::Rotl_I64,
+			Instruction::I64Rotr => Self::Rotr_I64,
+			Instruction::F32Eq | Instruction::F64Eq => Self::Eq_FN,
+			Instruction::F32Ne | Instruction::F64Ne => Self::Ne_FN,
+			Instruction::F32Lt | Instruction::F64Lt => Self::Lt_FN,
+			Instruction::F32Gt | Instruction::F64Gt => Self::Gt_FN,
+			Instruction::F32Le | Instruction::F64Le => Self::Le_FN,
+			Instruction::F32Ge | Instruction::F64Ge => Self::Ge_FN,
+			Instruction::F32Add | Instruction::F64Add => Self::Add_FN,
+			Instruction::F32Sub | Instruction::F64Sub => Self::Sub_FN,
+			Instruction::F32Mul | Instruction::F64Mul => Self::Mul_FN,
+			Instruction::F32Div | Instruction::F64Div => Self::Div_FN,
+			Instruction::F32Min | Instruction::F64Min => Self::Min_FN,
+			Instruction::F32Max | Instruction::F64Max => Self::Max_FN,
+			Instruction::F32Copysign | Instruction::F64Copysign => Self::Copysign_FN,
+			_ => {
+				return Err(());
+			}
+		};
+
+		Ok(result)
+	}
+}

wasm/src/backend/ast/transformer.rs

@@ -0,0 +1,414 @@
+use parity_wasm::elements::{BlockType, Instruction, Local, Module};
+
+use crate::backend::translator::arity::{Arity, List as ArityList};
+
+use super::{
+	data::Memorize,
+	operation::{BinOp, UnOp},
+	{
+		data::{
+			AnyBinOp, AnyLoad, AnyStore, AnyUnOp, Backward, Br, BrIf, BrTable, Call, CallIndirect,
+			Expression, Forward, Function, GetGlobal, GetLocal, If, MemoryGrow, MemorySize, Return,
+			Select, SetGlobal, SetLocal, Statement, Value,
+		},
+		operation::{Load, Store},
+	},
+};
+
+pub struct Transformer<'a> {
+	// target state
+	wasm: &'a Module,
+	arity: &'a ArityList,
+	name: usize,
+
+	// translation state
+	pending: Vec<Vec<Expression>>,
+	stack: Vec<Expression>,
+	last_stack: usize,
+}
+
+fn local_sum(list: &[Local]) -> u32 {
+	list.iter().map(Local::count).sum()
+}
+
+fn is_else_stat(inst: &Instruction) -> bool {
+	inst == &Instruction::Else
+}
+
+impl<'a> Transformer<'a> {
+	pub fn new(wasm: &'a Module, arity: &'a ArityList, name: usize) -> Transformer<'a> {
+		Transformer {
+			wasm,
+			arity,
+			name,
+			pending: Vec::new(),
+			stack: Vec::new(),
+			last_stack: 0,
+		}
+	}
+
+	pub fn consume(mut self) -> Function {
+		debug_assert!(self.name != usize::MAX, "Not an indexed value");
+
+		let func = &self.wasm.code_section().unwrap().bodies()[self.name];
+		let body = self.new_forward(&mut func.code().elements());
+
+		Function {
+			num_param: self.arity.in_arity[self.name].num_param,
+			num_local: local_sum(func.locals()),
+			num_stack: u32::try_from(self.last_stack).unwrap(),
+			body,
+		}
+	}
+
+	fn push_recall(&mut self, num: u32) {
+		let len = self.stack.len();
+
+		(len..len + num as usize)
+			.map(Expression::Recall)
+			.for_each(|v| self.stack.push(v));
+	}
+
+	fn push_block_result(&mut self, typ: BlockType) {
+		if matches!(typ, BlockType::NoResult) {
+			return;
+		}
+
+		self.push_recall(1);
+	}
+
+	// If any expressions are still pending at the start of
+	// statement, we leak them into variables.
+	// Since expressions do not have set ordering rules, this is
+	// safe and condenses code.
+	fn gen_leak_pending(&mut self, stat: &mut Vec<Statement>) {
+		self.last_stack = self.last_stack.max(self.stack.len());
+
+		for (i, v) in self
+			.stack
+			.iter_mut()
+			.enumerate()
+			.filter(|v| !v.1.is_recalling(v.0))
+		{
+			let new = Expression::Recall(i);
+			let mem = Memorize {
+				var: i,
+				value: std::mem::replace(v, new),
+			};
+
+			stat.push(Statement::Memorize(mem));
+		}
+	}
+
+	// Pending expressions are put to sleep before entering
+	// a control structure so that they are not lost.
+	fn save_pending(&mut self) {
+		self.pending.push(self.stack.clone());
+	}
+
+	fn load_pending(&mut self) {
+		self.stack = self.pending.pop().unwrap();
+	}
+
+	fn gen_return(&mut self, stat: &mut Vec<Statement>) {
+		let num = self.arity.in_arity[self.name].num_result as usize;
+		let list = self.stack.split_off(self.stack.len() - num);
+
+		self.gen_leak_pending(stat);
+		stat.push(Statement::Return(Return { list }));
+	}
+
+	fn gen_call(&mut self, func: u32, stat: &mut Vec<Statement>) {
+		let arity = self.arity.arity_of(func as usize);
+
+		let param_list = self
+			.stack
+			.split_off(self.stack.len() - arity.num_param as usize);
+
+		let len = u32::try_from(self.stack.len()).unwrap();
+		let result = len..len + arity.num_result;
+
+		self.push_recall(arity.num_result);
+		self.gen_leak_pending(stat);
+		stat.push(Statement::Call(Call {
+			func,
+			result,
+			param_list,
+		}));
+	}
+
+	fn gen_call_indirect(&mut self, typ: u32, table: u8, stat: &mut Vec<Statement>) {
+		let types = self.wasm.type_section().unwrap().types();
+		let arity = Arity::from_index(types, typ);
+
+		let index = self.stack.pop().unwrap();
+		let param_list = self
+			.stack
+			.split_off(self.stack.len() - arity.num_param as usize);
+
+		let len = u32::try_from(self.stack.len()).unwrap();
+		let result = len..len + arity.num_result;
+
+		self.push_recall(arity.num_result);
+		self.gen_leak_pending(stat);
+		stat.push(Statement::CallIndirect(CallIndirect {
+			table,
+			index,
+			result,
+			param_list,
+		}));
+	}
+
+	fn push_load(&mut self, op: Load, offset: u32) {
+		let pointer = Box::new(self.stack.pop().unwrap());
+
+		self.stack.push(Expression::AnyLoad(AnyLoad {
+			op,
+			offset,
+			pointer,
+		}));
+	}
+
+	fn gen_store(&mut self, op: Store, offset: u32, stat: &mut Vec<Statement>) {
+		let value = self.stack.pop().unwrap();
+		let pointer = self.stack.pop().unwrap();
+
+		self.gen_leak_pending(stat);
+		stat.push(Statement::AnyStore(AnyStore {
+			op,
+			offset,
+			pointer,
+			value,
+		}));
+	}
+
+	fn push_constant(&mut self, value: Value) {
+		self.stack.push(Expression::Value(value));
+	}
+
+	fn push_un_op(&mut self, op: UnOp) {
+		let rhs = Box::new(self.stack.pop().unwrap());
+
+		self.stack.push(Expression::AnyUnOp(AnyUnOp { op, rhs }));
+	}
+
+	fn push_bin_op(&mut self, op: BinOp) {
+		let rhs = Box::new(self.stack.pop().unwrap());
+		let lhs = Box::new(self.stack.pop().unwrap());
+
+		self.stack
+			.push(Expression::AnyBinOp(AnyBinOp { op, lhs, rhs }));
+	}
+
+	fn new_body(&mut self, list: &mut &[Instruction]) -> Vec<Statement> {
+		use Instruction as Inst;
+
+		let mut stat = Vec::new();
+
+		loop {
+			let inst = &list[0];
+
+			*list = &list[1..];
+
+			if let Ok(op) = UnOp::try_from(inst) {
+				self.push_un_op(op);
+
+				continue;
+			} else if let Ok(op) = BinOp::try_from(inst) {
+				self.push_bin_op(op);
+
+				continue;
+			}
+
+			match inst {
+				Inst::Nop => {}
+				Inst::Unreachable => {
+					self.gen_leak_pending(&mut stat);
+					stat.push(Statement::Unreachable);
+				}
+				Inst::Block(t) => {
+					self.gen_leak_pending(&mut stat);
+
+					let data = self.new_forward(list);
+
+					self.push_block_result(*t);
+					stat.push(Statement::Forward(data));
+				}
+				Inst::Loop(t) => {
+					self.gen_leak_pending(&mut stat);
+
+					let data = self.new_backward(list);
+
+					self.push_block_result(*t);
+					stat.push(Statement::Backward(data));
+				}
+				Inst::If(t) => {
+					let cond = self.stack.pop().unwrap();
+
+					self.gen_leak_pending(&mut stat);
+
+					let data = self.new_if(cond, list);
+
+					self.push_block_result(*t);
+					stat.push(Statement::If(data));
+				}
+				Inst::Else => {
+					self.gen_leak_pending(&mut stat);
+
+					break;
+				}
+				Inst::End => {
+					if list.is_empty() && !self.stack.is_empty() {
+						self.gen_return(&mut stat);
+					} else {
+						self.gen_leak_pending(&mut stat);
+					}
+
+					break;
+				}
+				Inst::Br(i) => {
+					self.gen_leak_pending(&mut stat);
+					stat.push(Statement::Br(Br { target: *i }));
+				}
+				Inst::BrIf(i) => {
+					let cond = self.stack.pop().unwrap();
+
+					self.gen_leak_pending(&mut stat);
+					stat.push(Statement::BrIf(BrIf { cond, target: *i }));
+				}
+				Inst::BrTable(t) => {
+					let cond = self.stack.pop().unwrap();
+
+					self.gen_leak_pending(&mut stat);
+					stat.push(Statement::BrTable(BrTable {
+						cond,
+						data: *t.clone(),
+					}));
+				}
+				Inst::Return => {
+					self.gen_return(&mut stat);
+				}
+				Inst::Call(i) => {
+					self.gen_call(*i, &mut stat);
+				}
+				Inst::CallIndirect(i, t) => {
+					self.gen_call_indirect(*i, *t, &mut stat);
+				}
+				Inst::Drop => {
+					self.stack.pop().unwrap();
+				}
+				Inst::Select => {
+					let cond = Box::new(self.stack.pop().unwrap());
+					let b = Box::new(self.stack.pop().unwrap());
+					let a = Box::new(self.stack.pop().unwrap());
+
+					self.stack.push(Expression::Select(Select { cond, a, b }));
+				}
+				Inst::GetLocal(i) => {
+					self.stack.push(Expression::GetLocal(GetLocal { var: *i }));
+				}
+				Inst::SetLocal(i) => {
+					let value = self.stack.pop().unwrap();
+
+					self.gen_leak_pending(&mut stat);
+					stat.push(Statement::SetLocal(SetLocal { var: *i, value }));
+				}
+				Inst::TeeLocal(i) => {
+					self.gen_leak_pending(&mut stat);
+
+					let value = self.stack.last().unwrap().clone();
+
+					stat.push(Statement::SetLocal(SetLocal { var: *i, value }));
+				}
+				Inst::GetGlobal(i) => {
+					self.stack
+						.push(Expression::GetGlobal(GetGlobal { var: *i }));
+				}
+				Inst::SetGlobal(i) => {
+					let value = self.stack.pop().unwrap();
+
+					stat.push(Statement::SetGlobal(SetGlobal { var: *i, value }));
+				}
+				Inst::I32Load(_, o) => self.push_load(Load::I32, *o),
+				Inst::I64Load(_, o) => self.push_load(Load::I64, *o),
+				Inst::F32Load(_, o) => self.push_load(Load::F32, *o),
+				Inst::F64Load(_, o) => self.push_load(Load::F64, *o),
+				Inst::I32Load8S(_, o) => self.push_load(Load::I32_I8, *o),
+				Inst::I32Load8U(_, o) => self.push_load(Load::I32_U8, *o),
+				Inst::I32Load16S(_, o) => self.push_load(Load::I32_I16, *o),
+				Inst::I32Load16U(_, o) => self.push_load(Load::I32_U16, *o),
+				Inst::I64Load8S(_, o) => self.push_load(Load::I64_I8, *o),
+				Inst::I64Load8U(_, o) => self.push_load(Load::I64_U8, *o),
+				Inst::I64Load16S(_, o) => self.push_load(Load::I64_I16, *o),
+				Inst::I64Load16U(_, o) => self.push_load(Load::I64_U16, *o),
+				Inst::I64Load32S(_, o) => self.push_load(Load::I64_I32, *o),
+				Inst::I64Load32U(_, o) => self.push_load(Load::I64_U32, *o),
+				Inst::I32Store(_, o) => self.gen_store(Store::I32, *o, &mut stat),
+				Inst::I64Store(_, o) => self.gen_store(Store::I64, *o, &mut stat),
+				Inst::F32Store(_, o) => self.gen_store(Store::F32, *o, &mut stat),
+				Inst::F64Store(_, o) => self.gen_store(Store::F64, *o, &mut stat),
+				Inst::I32Store8(_, o) => self.gen_store(Store::I32_N8, *o, &mut stat),
+				Inst::I32Store16(_, o) => self.gen_store(Store::I32_N16, *o, &mut stat),
+				Inst::I64Store8(_, o) => self.gen_store(Store::I64_N8, *o, &mut stat),
+				Inst::I64Store16(_, o) => self.gen_store(Store::I64_N16, *o, &mut stat),
+				Inst::I64Store32(_, o) => self.gen_store(Store::I64_N32, *o, &mut stat),
+				Inst::CurrentMemory(i) => {
+					self.stack
+						.push(Expression::MemorySize(MemorySize { memory: *i }));
+				}
+				Inst::GrowMemory(i) => {
+					let value = Box::new(self.stack.pop().unwrap());
+
+					// `MemoryGrow` is an expression *but* it has side effects
+					self.stack
+						.push(Expression::MemoryGrow(MemoryGrow { memory: *i, value }));
+
+					self.gen_leak_pending(&mut stat);
+				}
+				Inst::I32Const(v) => self.push_constant(Value::I32(*v)),
+				Inst::I64Const(v) => self.push_constant(Value::I64(*v)),
+				Inst::F32Const(v) => self.push_constant(Value::F32(f32::from_bits(*v))),
+				Inst::F64Const(v) => self.push_constant(Value::F64(f64::from_bits(*v))),
+				_ => unreachable!(),
+			}
+		}
+
+		stat
+	}
+
+	fn new_stored_body(&mut self, list: &mut &[Instruction]) -> Vec<Statement> {
+		self.save_pending();
+
+		let body = self.new_body(list);
+
+		self.load_pending();
+
+		body
+	}
+
+	fn new_if(&mut self, cond: Expression, list: &mut &[Instruction]) -> If {
+		let copied = <&[Instruction]>::clone(list);
+		let truthy = self.new_stored_body(list);
+
+		let end = copied.len() - list.len() - 1;
+		let falsey = is_else_stat(&copied[end]).then(|| self.new_stored_body(list));
+
+		If {
+			cond,
+			truthy,
+			falsey,
+		}
+	}
+
+	fn new_backward(&mut self, list: &mut &[Instruction]) -> Backward {
+		Backward {
+			body: self.new_stored_body(list),
+		}
+	}
+
+	fn new_forward(&mut self, list: &mut &[Instruction]) -> Forward {
+		Forward {
+			body: self.new_stored_body(list),
+		}
+	}
+}

wasm/src/backend/edition/data.rs

@@ -0,0 +1,51 @@
+use std::{
+	fmt::Display,
+	io::{Result, Write},
+};
+
+use super::{luajit::LuaJIT, luau::Luau};
+
+pub struct Infix<T> {
+	rhs: &'static str,
+	inner: T,
+}
+
+impl<T> Infix<T> {
+	pub fn new(rhs: &'static str, inner: T) -> Self {
+		Infix { rhs, inner }
+	}
+}
+
+impl<T> Display for Infix<T>
+where
+	T: Display,
+{
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		self.inner.fmt(f)?;
+		self.rhs.fmt(f)
+	}
+}
+
+pub trait Edition {
+	fn runtime(&self) -> &'static str;
+
+	fn start_block(&self, w: &mut dyn Write) -> Result<()>;
+	fn start_loop(&self, level: usize, w: &mut dyn Write) -> Result<()>;
+	fn start_if(&self, cond: &str, w: &mut dyn Write) -> Result<()>;
+	fn end_block(&self, level: usize, w: &mut dyn Write) -> Result<()>;
+	fn end_loop(&self, w: &mut dyn Write) -> Result<()>;
+	fn end_if(&self, level: usize, w: &mut dyn Write) -> Result<()>;
+
+	fn br_target(&self, level: usize, in_loop: bool, w: &mut dyn Write) -> Result<()>;
+	fn br_to_level(&self, level: usize, up: usize, is_loop: bool, w: &mut dyn Write) -> Result<()>;
+
+	fn i64(&self, i: i64) -> Infix<i64>;
+}
+
+pub fn from_string(name: &str) -> Option<&'static dyn Edition> {
+	match name.to_ascii_lowercase().as_str() {
+		"luau" => Some(&Luau),
+		"luajit" => Some(&LuaJIT),
+		_ => None,
+	}
+}

wasm/src/backend/edition/luajit.rs

@@ -0,0 +1,56 @@
+use std::io::{Result, Write};
+
+use super::data::{Edition, Infix};
+
+pub struct LuaJIT;
+
+impl Edition for LuaJIT {
+	fn runtime(&self) -> &'static str {
+		"'luajit'"
+	}
+
+	fn start_block(&self, w: &mut dyn Write) -> Result<()> {
+		write!(w, "do ")
+	}
+
+	fn start_loop(&self, level: usize, w: &mut dyn Write) -> Result<()> {
+		write!(w, "do ")?;
+		write!(w, "::continue_at_{}::", level)
+	}
+
+	fn start_if(&self, cond: &str, w: &mut dyn Write) -> Result<()> {
+		write!(w, "if {} ~= 0 then ", cond)
+	}
+
+	fn end_block(&self, level: usize, w: &mut dyn Write) -> Result<()> {
+		write!(w, "::continue_at_{}::", level)?;
+		write!(w, "end ")
+	}
+
+	fn end_loop(&self, w: &mut dyn Write) -> Result<()> {
+		write!(w, "end ")
+	}
+
+	fn end_if(&self, level: usize, w: &mut dyn Write) -> Result<()> {
+		write!(w, "::continue_at_{}::", level)?;
+		write!(w, "end ")
+	}
+
+	fn br_target(&self, _level: usize, _in_loop: bool, _w: &mut dyn Write) -> Result<()> {
+		Ok(())
+	}
+
+	fn br_to_level(
+		&self,
+		level: usize,
+		up: usize,
+		_is_loop: bool,
+		w: &mut dyn Write,
+	) -> Result<()> {
+		write!(w, "goto continue_at_{} ", level - up)
+	}
+
+	fn i64(&self, i: i64) -> Infix<i64> {
+		Infix::new("LL", i)
+	}
+}

wasm/src/backend/edition/luau.rs

@@ -0,0 +1,75 @@
+use std::io::{Result, Write};
+
+use super::data::{Edition, Infix};
+
+pub struct Luau;
+
+impl Edition for Luau {
+	fn runtime(&self) -> &'static str {
+		"script.Runtime"
+	}
+
+	fn start_block(&self, w: &mut dyn Write) -> Result<()> {
+		write!(w, "while true do ")
+	}
+
+	fn start_loop(&self, _level: usize, w: &mut dyn Write) -> Result<()> {
+		write!(w, "while true do ")
+	}
+
+	fn start_if(&self, cond: &str, w: &mut dyn Write) -> Result<()> {
+		write!(w, "while true do ")?;
+		write!(w, "if {} ~= 0 then ", cond)
+	}
+
+	fn end_block(&self, _level: usize, w: &mut dyn Write) -> Result<()> {
+		write!(w, "break ")?;
+		write!(w, "end ")
+	}
+
+	fn end_loop(&self, w: &mut dyn Write) -> Result<()> {
+		write!(w, "break ")?;
+		write!(w, "end ")
+	}
+
+	fn end_if(&self, _level: usize, w: &mut dyn Write) -> Result<()> {
+		write!(w, "end ")?;
+		write!(w, "break ")?;
+		write!(w, "end ")
+	}
+
+	fn br_target(&self, level: usize, in_loop: bool, w: &mut dyn Write) -> Result<()> {
+		write!(w, "if desired then ")?;
+		write!(w, "if desired == {} then ", level)?;
+		write!(w, "desired = nil ")?;
+
+		if in_loop {
+			write!(w, "continue ")?;
+		}
+
+		write!(w, "end ")?;
+		write!(w, "break ")?;
+		write!(w, "end ")
+	}
+
+	fn br_to_level(&self, level: usize, up: usize, is_loop: bool, w: &mut dyn Write) -> Result<()> {
+		write!(w, "do ")?;
+
+		if up == 0 {
+			if is_loop {
+				write!(w, "continue ")?;
+			} else {
+				write!(w, "break ")?;
+			}
+		} else {
+			write!(w, "desired = {} ", level - up)?;
+			write!(w, "break ")?;
+		}
+
+		write!(w, "end ")
+	}
+
+	fn i64(&self, i: i64) -> Infix<i64> {
+		Infix::new("", i)
+	}
+}

wasm/src/backend/edition/mod.rs

@@ -0,0 +1,3 @@
+pub mod data;
+pub mod luajit;
+pub mod luau;

wasm/src/backend/mod.rs

@@ -0,0 +1,4 @@
+mod ast;
+pub mod edition;
+pub mod translator;
+mod visitor;

wasm/src/backend/translator/arity.rs

@@ -0,0 +1,81 @@
+use std::convert::TryInto;
+
+use parity_wasm::elements::{External, FunctionType, ImportEntry, Module, Type};
+
+pub struct Arity {
+	pub num_param: u32,
+	pub num_result: u32,
+}
+
+impl Arity {
+	fn from_type(typ: &FunctionType) -> Self {
+		let num_param = typ.params().len().try_into().unwrap();
+		let num_result = typ.results().len().try_into().unwrap();
+
+		Self {
+			num_param,
+			num_result,
+		}
+	}
+
+	pub fn from_index(types: &[Type], index: u32) -> Self {
+		let Type::Function(typ) = &types[index as usize];
+
+		Self::from_type(typ)
+	}
+}
+
+pub struct List {
+	pub ex_arity: Vec<Arity>,
+	pub in_arity: Vec<Arity>,
+}
+
+impl List {
+	pub fn new(parent: &Module) -> Self {
+		Self {
+			ex_arity: Self::new_arity_ex_list(parent),
+			in_arity: Self::new_arity_in_list(parent),
+		}
+	}
+
+	pub fn arity_of(&self, index: usize) -> &Arity {
+		let offset = self.ex_arity.len();
+
+		self.ex_arity
+			.get(index)
+			.or_else(|| self.in_arity.get(index - offset))
+			.unwrap()
+	}
+
+	fn new_arity_ext(types: &[Type], import: &ImportEntry) -> Option<Arity> {
+		if let External::Function(i) = import.external() {
+			Some(Arity::from_index(types, *i))
+		} else {
+			None
+		}
+	}
+
+	fn new_arity_in_list(wasm: &Module) -> Vec<Arity> {
+		let (types, funcs) = match (wasm.type_section(), wasm.function_section()) {
+			(Some(t), Some(f)) => (t.types(), f.entries()),
+			_ => return Vec::new(),
+		};
+
+		funcs
+			.iter()
+			.map(|i| Arity::from_index(types, i.type_ref()))
+			.collect()
+	}
+
+	fn new_arity_ex_list(wasm: &Module) -> Vec<Arity> {
+		let (types, imports) = match (wasm.type_section(), wasm.import_section()) {
+			(Some(t), Some(i)) => (t.types(), i.entries()),
+			_ => return Vec::new(),
+		};
+
+		imports
+			.iter()
+			.filter_map(|i| Self::new_arity_ext(types, i))
+			.collect()
+	}
+}

wasm/src/backend/translator/data.rs

@@ -0,0 +1,306 @@
+use std::{
+	collections::BTreeSet,
+	io::{Result, Write},
+};
+
+use parity_wasm::elements::{
+	External, ImportCountType, Instruction, Internal, Module as WasmModule, ResizableLimits,
+};
+
+use crate::backend::{
+	ast::{data::Function, transformer::Transformer},
+	edition::data::Edition,
+	visitor::localize,
+};
+
+use super::{arity::List as ArityList, writer::Data};
+
+fn aux_internal_index(internal: Internal) -> u32 {
+	match internal {
+		Internal::Function(v) | Internal::Table(v) | Internal::Memory(v) | Internal::Global(v) => v,
+	}
+}
+
+fn new_limit_max(limits: &ResizableLimits) -> String {
+	match limits.maximum() {
+		Some(v) => v.to_string(),
+		None => "math.huge".to_string(),
+	}
+}
+
+fn gen_table_init(limit: &ResizableLimits, w: &mut dyn Write) -> Result<()> {
+	let a = limit.initial();
+	let b = new_limit_max(limit);
+
+	write!(w, "{{ min = {}, max = {}, data = {{}} }}", a, b)
+}
+
+fn gen_memory_init(limit: &ResizableLimits, w: &mut dyn Write) -> Result<()> {
+	let a = limit.initial();
+	let b = new_limit_max(limit);
+
+	write!(w, "rt.memory.new({}, {})", a, b)
+}
+
+fn gen_nil_array(name: &str, len: usize, w: &mut dyn Write) -> Result<()> {
+	if len == 0 {
+		return Ok(());
+	}
+
+	write!(w, "local {} = {{[0] = {}}}", name, "nil, ".repeat(len))
+}
+
+pub fn gen_expression(code: &[Instruction], w: &mut dyn Write) -> Result<()> {
+	assert!(code.len() == 2);
+
+	let inst = code.first().unwrap();
+
+	match *inst {
+		Instruction::I32Const(v) => write!(w, "{} ", v),
+		Instruction::I64Const(v) => write!(w, "{} ", v),
+		Instruction::F32Const(v) => write!(w, "{} ", f32::from_bits(v)),
+		Instruction::F64Const(v) => write!(w, "{} ", f64::from_bits(v)),
+		Instruction::GetGlobal(i) => write!(w, "GLOBAL_LIST[{}].value ", i),
+		_ => unreachable!(),
+	}
+}
+
+pub struct Module<'a> {
+	wasm: &'a WasmModule,
+	arity: ArityList,
+}
+
+impl<'a> Module<'a> {
+	pub fn new(wasm: &'a WasmModule) -> Self {
+		let arity = ArityList::new(wasm);
+
+		Self { wasm, arity }
+	}
+
+	fn gen_import_of<T>(&self, w: &mut dyn Write, lower: &str, cond: T) -> Result<()>
+	where
+		T: Fn(&External) -> bool,
+	{
+		let import = match self.wasm.import_section() {
+			Some(v) => v.entries(),
+			None => return Ok(()),
+		};
+		let upper = lower.to_uppercase();
+
+		for (i, v) in import.iter().filter(|v| cond(v.external())).enumerate() {
+			let field = v.field();
+			let module = v.module();
+
+			write!(w, "{}[{}] = wasm.{}.{}.{} ", upper, i, module, lower, field)?;
+		}
+
+		Ok(())
+	}
+
+	fn gen_export_of<T>(&self, w: &mut dyn Write, lower: &str, cond: T) -> Result<()>
+	where
+		T: Fn(&Internal) -> bool,
+	{
+		let export = match self.wasm.export_section() {
+			Some(v) => v.entries(),
+			None => return Ok(()),
+		};
+		let upper = lower.to_uppercase();
+
+		write!(w, "{} = {{", lower)?;
+
+		for v in export.iter().filter(|v| cond(v.internal())) {
+			let field = v.field();
+			let index = aux_internal_index(*v.internal());
+
+			write!(w, "{} = {}[{}],", field, upper, index)?;
+		}
+
+		write!(w, "}},")
+	}
+
+	fn gen_import_list(&self, w: &mut dyn Write) -> Result<()> {
+		self.gen_import_of(w, "func_list", |v| matches!(v, External::Function(_)))?;
+		self.gen_import_of(w, "table_list", |v| matches!(v, External::Table(_)))?;
+		self.gen_import_of(w, "memory_list", |v| matches!(v, External::Memory(_)))?;
+		self.gen_import_of(w, "global_list", |v| matches!(v, External::Global(_)))
+	}
+
+	fn gen_export_list(&self, w: &mut dyn Write) -> Result<()> {
+		self.gen_export_of(w, "func_list", |v| matches!(v, Internal::Function(_)))?;
+		self.gen_export_of(w, "table_list", |v| matches!(v, Internal::Table(_)))?;
+		self.gen_export_of(w, "memory_list", |v| matches!(v, Internal::Memory(_)))?;
+		self.gen_export_of(w, "global_list", |v| matches!(v, Internal::Global(_)))
+	}
+
+	fn gen_table_list(&self, w: &mut dyn Write) -> Result<()> {
+		let table = match self.wasm.table_section() {
+			Some(v) => v.entries(),
+			None => return Ok(()),
+		};
+		let offset = self.wasm.import_count(ImportCountType::Table);
+
+		for (i, v) in table.iter().enumerate() {
+			let index = i + offset;
+
+			write!(w, "TABLE_LIST[{}] =", index)?;
+			gen_table_init(v.limits(), w)?;
+		}
+
+		Ok(())
+	}
+
+	fn gen_memory_list(&self, w: &mut dyn Write) -> Result<()> {
+		let memory = match self.wasm.memory_section() {
+			Some(v) => v.entries(),
+			None => return Ok(()),
+		};
+		let offset = self.wasm.import_count(ImportCountType::Memory);
+
+		for (i, v) in memory.iter().enumerate() {
+			let index = i + offset;
+
+			write!(w, "MEMORY_LIST[{}] =", index)?;
+			gen_memory_init(v.limits(), w)?;
+		}
+
+		Ok(())
+	}
+
+	fn gen_global_list(&self, w: &mut dyn Write) -> Result<()> {
+		let global = match self.wasm.global_section() {
+			Some(v) => v,
+			None => return Ok(()),
+		};
+		let offset = self.wasm.import_count(ImportCountType::Global);
+
+		for (i, v) in global.entries().iter().enumerate() {
+			let index = i + offset;
+
+			write!(w, "GLOBAL_LIST[{}] = {{ value =", index)?;
+
+			gen_expression(v.init_expr().code(), w)?;
+
+			write!(w, "}}")?;
+		}
+
+		Ok(())
+	}
+
+	fn gen_element_list(&self, w: &mut dyn Write) -> Result<()> {
+		let element = match self.wasm.elements_section() {
+			Some(v) => v.entries(),
+			None => return Ok(()),
+		};
+
+		for v in element {
+			write!(w, "do ")?;
+			write!(w, "local target = TABLE_LIST[{}].data ", v.index())?;
+			write!(w, "local offset =")?;
+
+			gen_expression(v.offset().as_ref().unwrap().code(), w)?;
+
+			write!(w, "local data = {{")?;
+
+			v.members()
+				.iter()
+				.try_for_each(|v| write!(w, "FUNC_LIST[{}],", v))?;
+
+			write!(w, "}}")?;
+
+			write!(w, "table.move(data, 1, #data, offset, target)")?;
+
+			write!(w, "end ")?;
+		}
+
+		Ok(())
+	}
+
+	fn gen_data_list(&self, w: &mut dyn Write) -> Result<()> {
+		let data = match self.wasm.data_section() {
+			Some(v) => v.entries(),
+			None => return Ok(()),
+		};
+
+		for v in data {
+			write!(w, "do ")?;
+			write!(w, "local target = MEMORY_LIST[{}]", v.index())?;
+			write!(w, "local offset =")?;
+
+			gen_expression(v.offset().as_ref().unwrap().code(), w)?;
+
+			write!(w, "local data = \"")?;
+
+			v.value()
+				.iter()
+				.try_for_each(|v| write!(w, "\\x{:02X}", v))?;
+
+			write!(w, "\"")?;
+
+			write!(w, "rt.memory.init(target, offset, data)")?;
+
+			write!(w, "end ")?;
+		}
+
+		Ok(())
+	}
+
+	fn gen_start_point(&self, w: &mut dyn Write) -> Result<()> {
+		write!(w, "local function run_init_code()")?;
+		self.gen_table_list(w)?;
+		self.gen_memory_list(w)?;
+		self.gen_global_list(w)?;
+		self.gen_element_list(w)?;
+		self.gen_data_list(w)?;
+		write!(w, "end ")?;
+
+		write!(w, "return function(wasm)")?;
+		self.gen_import_list(w)?;
+		write!(w, "run_init_code()")?;
+
+		if let Some(start) = self.wasm.start_section() {
+			write!(w, "FUNC_LIST[{}]()", start)?;
+		}
+
+		write!(w, "return {{")?;
+		self.gen_export_list(w)?;
+		write!(w, "}} end ")
+	}
+
+	fn gen_localize(func_list: &[Function], w: &mut dyn Write) -> Result<()> {
+		let mut loc_set = BTreeSet::new();
+
+		for func in func_list {
+			loc_set.extend(localize::visit(func));
+		}
+
+		loc_set
+			.into_iter()
+			.try_for_each(|(a, b)| write!(w, "local {0}_{1} = rt.{0}.{1} ", a, b))
+	}
+
+	pub fn translate(&self, ed: &dyn Edition, w: &mut dyn Write) -> Result<()> {
+		write!(w, "local rt = require({})", ed.runtime())?;
+
+		let func_list: Vec<_> = (0..self.arity.in_arity.len())
+			.map(|i| Transformer::new(self.wasm, &self.arity, i).consume())
+			.collect();
+
+		Self::gen_localize(&func_list, w)?;
+
+		gen_nil_array("FUNC_LIST", self.wasm.functions_space(), w)?;
+		gen_nil_array("TABLE_LIST", self.wasm.table_space(), w)?;
+		gen_nil_array("MEMORY_LIST", self.wasm.memory_space(), w)?;
+		gen_nil_array("GLOBAL_LIST", self.wasm.globals_space(), w)?;
+
+		let offset = self.arity.ex_arity.len();
+
+		for (i, v) in func_list.into_iter().enumerate() {
+			write!(w, "FUNC_LIST[{}] =", i + offset)?;
+
+			v.output(&mut Data::new(v.num_param, ed), w)?;
+		}
+
+		self.gen_start_point(w)
+	}
+}

wasm/src/backend/translator/mod.rs

@@ -0,0 +1,3 @@
+pub mod arity;
+pub mod data;
+mod writer;

wasm/src/backend/translator/writer.rs

@@ -0,0 +1,503 @@
+use std::{
+	io::{Result, Write},
+	ops::Range,
+};
+
+use crate::backend::{
+	ast::data::{
+		AnyBinOp, AnyLoad, AnyStore, AnyUnOp, Backward, Br, BrIf, BrTable, Call, CallIndirect,
+		Expression, Forward, Function, GetGlobal, GetLocal, If, Memorize, MemoryGrow, MemorySize,
+		Return, Select, SetGlobal, SetLocal, Statement, Value,
+	},
+	edition::data::Edition,
+	visitor::memory,
+};
+
+fn write_in_order(prefix: &'static str, len: u32, w: &mut dyn Write) -> Result<()> {
+	if len == 0 {
+		return Ok(());
+	}
+
+	write!(w, "{}_{}", prefix, 0)?;
+	(1..len).try_for_each(|i| write!(w, ", {}_{}", prefix, i))
+}
+
+fn write_br_gadget(rem: usize, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+	match d.label_list.last() {
+		Some(Label::Forward | Label::If) => d.edition.br_target(rem, false, w),
+		Some(Label::Backward) => d.edition.br_target(rem, true, w),
+		None => Ok(()),
+	}
+}
+
+pub fn condense_jump_table(list: &[u32]) -> Vec<(usize, usize, u32)> {
+	let mut result = Vec::new();
+	let mut index = 0;
+
+	while index < list.len() {
+		let start = index;
+
+		loop {
+			index += 1;
+
+			// if end of list or next value is not equal, break
+			if index == list.len() || list[index - 1] != list[index] {
+				break;
+			}
+		}
+
+		result.push((start, index - 1, list[start]));
+	}
+
+	result
+}
+
+#[derive(PartialEq, Eq)]
+enum Label {
+	Forward,
+	Backward,
+	If,
+}
+
+pub struct Data<'a> {
+	label_list: Vec<Label>,
+	num_param: u32,
+	edition: &'a dyn Edition,
+}
+
+impl<'a> Data<'a> {
+	pub fn new(num_param: u32, edition: &'a dyn Edition) -> Self {
+		Self {
+			label_list: Vec::new(),
+			num_param,
+			edition,
+		}
+	}
+}
+
+impl Select {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		write!(w, "(")?;
+		self.cond.output(d, w)?;
+		write!(w, " ~= 0 and ")?;
+		self.a.output(d, w)?;
+		write!(w, " or ")?;
+		self.b.output(d, w)?;
+		write!(w, ")")
+	}
+}
+
+impl GetLocal {
+	fn write_variable(var: u32, d: &Data, w: &mut dyn Write) -> Result<()> {
+		if let Some(rem) = var.checked_sub(d.num_param) {
+			write!(w, "loc_{} ", rem)
+		} else {
+			write!(w, "param_{} ", var)
+		}
+	}
+
+	fn output(&self, d: &Data, w: &mut dyn Write) -> Result<()> {
+		Self::write_variable(self.var, d, w)
+	}
+}
+
+impl GetGlobal {
+	fn output(&self, w: &mut dyn Write) -> Result<()> {
+		write!(w, "GLOBAL_LIST[{}].value ", self.var)
+	}
+}
+
+impl AnyLoad {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		write!(w, "load_{}(memory_at_0, ", self.op.as_name())?;
+		self.pointer.output(d, w)?;
+		write!(w, "+ {})", self.offset)
+	}
+}
+
+impl MemorySize {
+	fn output(&self, w: &mut dyn Write) -> Result<()> {
+		write!(w, "rt.memory.size(memory_at_{})", self.memory)
+	}
+}
+
+impl MemoryGrow {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		write!(w, "rt.memory.grow(memory_at_{}, ", self.memory)?;
+		self.value.output(d, w)?;
+		write!(w, ")")
+	}
+}
+
+impl Value {
+	fn write_f32(f: f32, w: &mut dyn Write) -> Result<()> {
+		let sign = if f.is_sign_negative() { "-" } else { "" };
+
+		if f.is_infinite() {
+			write!(w, "{}math.huge", sign)
+		} else if f.is_nan() {
+			write!(w, "{}0/0", sign)
+		} else {
+			write!(w, "{:e}", f)
+		}
+	}
+
+	fn write_f64(f: f64, w: &mut dyn Write) -> Result<()> {
+		let sign = if f.is_sign_negative() { "-" } else { "" };
+
+		if f.is_infinite() {
+			write!(w, "{}math.huge", sign)
+		} else if f.is_nan() {
+			write!(w, "{}0/0", sign)
+		} else {
+			write!(w, "{:e}", f)
+		}
+	}
+
+	fn output(&self, d: &Data, w: &mut dyn Write) -> Result<()> {
+		match self {
+			Self::I32(i) => write!(w, "{} ", i),
+			Self::I64(i) => write!(w, "{} ", d.edition.i64(*i)),
+			Self::F32(f) => Self::write_f32(*f, w),
+			Self::F64(f) => Self::write_f64(*f, w),
+		}
+	}
+}
+
+impl AnyUnOp {
+	fn write_as_call(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		let (a, b) = self.op.as_name();
+
+		write!(w, "{}_{}(", a, b)?;
+		self.rhs.output(d, w)?;
+		write!(w, ")")
+	}
+
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		if let Some(op) = self.op.as_operator() {
+			write!(w, "{}", op)?;
+			self.rhs.output(d, w)
+		} else {
+			self.write_as_call(d, w)
+		}
+	}
+}
+
+impl AnyBinOp {
+	fn write_as_op(&self, op: &'static str, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		write!(w, "(")?;
+		self.lhs.output(d, w)?;
+		write!(w, "{} ", op)?;
+		self.rhs.output(d, w)?;
+		write!(w, ")")
+	}
+
+	fn write_as_call(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		let (a, b) = self.op.as_name();
+
+		write!(w, "{}_{}(", a, b)?;
+		self.lhs.output(d, w)?;
+		write!(w, ", ")?;
+		self.rhs.output(d, w)?;
+		write!(w, ")")
+	}
+
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		if let Some(op) = self.op.as_operator() {
+			self.write_as_op(op, d, w)
+		} else {
+			self.write_as_call(d, w)
+		}
+	}
+}
+
+impl Expression {
+	fn write_list(list: &[Self], d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		list.iter().enumerate().try_for_each(|(i, v)| {
+			if i != 0 {
+				write!(w, ", ")?;
+			}
+
+			v.output(d, w)
+		})
+	}
+
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		match self {
+			Self::Recall(i) => write!(w, "reg_{} ", i),
+			Self::Select(s) => s.output(d, w),
+			Self::GetLocal(g) => g.output(d, w),
+			Self::GetGlobal(g) => g.output(w),
+			Self::AnyLoad(a) => a.output(d, w),
+			Self::MemorySize(m) => m.output(w),
+			Self::MemoryGrow(m) => m.output(d, w),
+			Self::Value(v) => v.output(d, w),
+			Self::AnyUnOp(a) => a.output(d, w),
+			Self::AnyBinOp(a) => a.output(d, w),
+		}
+	}
+
+	fn to_buffer(&self, d: &mut Data) -> Result<String> {
+		let mut buf = Vec::new();
+
+		self.output(d, &mut buf)?;
+
+		Ok(String::from_utf8(buf).unwrap())
+	}
+}
+
+impl Memorize {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		write!(w, "reg_{} = ", self.var)?;
+		self.value.output(d, w)
+	}
+}
+
+impl Forward {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		let rem = d.label_list.len();
+
+		d.label_list.push(Label::Forward);
+		d.edition.start_block(w)?;
+
+		self.body.iter().try_for_each(|s| s.output(d, w))?;
+
+		d.edition.end_block(rem, w)?;
+		d.label_list.pop().unwrap();
+
+		write_br_gadget(rem, d, w)
+	}
+}
+
+impl Backward {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		let rem = d.label_list.len();
+
+		d.label_list.push(Label::Backward);
+		d.edition.start_loop(rem, w)?;
+
+		self.body.iter().try_for_each(|s| s.output(d, w))?;
+
+		d.edition.end_loop(w)?;
+		d.label_list.pop().unwrap();
+
+		write_br_gadget(rem, d, w)
+	}
+}
+
+impl If {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		let rem = d.label_list.len();
+
+		d.label_list.push(Label::If);
+
+		let var = self.cond.to_buffer(d)?;
+
+		d.edition.start_if(&var, w)?;
+
+		self.truthy.iter().try_for_each(|s| s.output(d, w))?;
+
+		if let Some(v) = &self.falsey {
+			write!(w, "else ")?;
+
+			v.iter().try_for_each(|s| s.output(d, w))?;
+		}
+
+		d.edition.end_if(rem, w)?;
+		d.label_list.pop().unwrap();
+
+		write_br_gadget(rem, d, w)
+	}
+}
+
+impl Br {
+	fn write_at(up: u32, d: &Data, w: &mut dyn Write) -> Result<()> {
+		let up = up as usize;
+		let level = d.label_list.len() - 1;
+		let is_loop = d.label_list[level - up] == Label::Backward;
+
+		d.edition.br_to_level(level, up, is_loop, w)
+	}
+
+	fn output(&self, d: &Data, w: &mut dyn Write) -> Result<()> {
+		Self::write_at(self.target, d, w)
+	}
+}
+
+impl BrIf {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		write!(w, "if ")?;
+		self.cond.output(d, w)?;
+		write!(w, "~= 0 then ")?;
+		Br::write_at(self.target, d, w)?;
+		write!(w, "end ")
+	}
+}
+
+impl BrTable {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		write!(w, "local temp = ")?;
+		self.cond.output(d, w)?;
+		write!(w, " ")?;
+
+		for (start, end, dest) in condense_jump_table(&self.data.table) {
+			if start == end {
+				write!(w, "if temp == {} then ", start)?;
+			} else {
+				write!(w, "if temp >= {} and temp <= {} then ", start, end)?;
+			}
+
+			Br::write_at(dest, d, w)?;
+			write!(w, "else")?;
+		}
+
+		write!(w, " ")?;
+		Br::write_at(self.data.default, d, w)?;
+		write!(w, "end ")
+	}
+}
+
+impl Return {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		write!(w, "do return ")?;
+
+		self.list.iter().enumerate().try_for_each(|(i, v)| {
+			if i > 0 {
+				write!(w, ", ")?;
+			}
+
+			v.output(d, w)
+		})?;
+
+		write!(w, "end ")
+	}
+}
+
+impl Call {
+	fn write_result_list(range: Range<u32>, w: &mut dyn Write) -> Result<()> {
+		if range.is_empty() {
+			return Ok(());
+		}
+
+		range.clone().try_for_each(|i| {
+			if i != range.start {
+				write!(w, ", ")?;
+			}
+
+			write!(w, "reg_{}", i)
+		})?;
+
+		write!(w, " = ")
+	}
+
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		Self::write_result_list(self.result.clone(), w)?;
+
+		write!(w, "FUNC_LIST[{}](", self.func)?;
+
+		Expression::write_list(&self.param_list, d, w)?;
+
+		write!(w, ")")
+	}
+}
+
+impl CallIndirect {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		Call::write_result_list(self.result.clone(), w)?;
+
+		write!(w, "TABLE_LIST[{}].data[", self.table)?;
+
+		self.index.output(d, w)?;
+
+		write!(w, "](")?;
+
+		Expression::write_list(&self.param_list, d, w)?;
+
+		write!(w, ")")
+	}
+}
+
+impl SetLocal {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		GetLocal::write_variable(self.var, d, w)?;
+
+		write!(w, "= ")?;
+		self.value.output(d, w)
+	}
+}
+
+impl SetGlobal {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		write!(w, "GLOBAL_LIST[{}].value = ", self.var)?;
+		self.value.output(d, w)
+	}
+}
+
+impl AnyStore {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		write!(w, "store_{}(memory_at_0, ", self.op.as_name())?;
+		self.pointer.output(d, w)?;
+		write!(w, "+ {}, ", self.offset)?;
+		self.value.output(d, w)?;
+		write!(w, ")")
+	}
+}
+
+impl Statement {
+	fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		match self {
+			Statement::Unreachable => write!(w, "error(\"out of code bounds\")"),
+			Statement::Memorize(v) => v.output(d, w),
+			Statement::Forward(v) => v.output(d, w),
+			Statement::Backward(v) => v.output(d, w),
+			Statement::If(v) => v.output(d, w),
+			Statement::Br(v) => v.output(d, w),
+			Statement::BrIf(v) => v.output(d, w),
+			Statement::BrTable(v) => v.output(d, w),
+			Statement::Return(v) => v.output(d, w),
+			Statement::Call(v) => v.output(d, w),
+			Statement::CallIndirect(v) => v.output(d, w),
+			Statement::SetLocal(v) => v.output(d, w),
+			Statement::SetGlobal(v) => v.output(d, w),
+			Statement::AnyStore(v) => v.output(d, w),
+		}
+	}
+}
+
+impl Function {
+	fn write_variable_list(&self, w: &mut dyn Write) -> Result<()> {
+		if self.num_local != 0 {
+			let list = vec!["0"; self.num_local as usize].join(", ");
+
+			write!(w, "local ")?;
+			write_in_order("loc", self.num_local, w)?;
+			write!(w, " = {} ", list)?;
+		}
+
+		if self.num_stack != 0 {
+			write!(w, "local ")?;
+			write_in_order("reg", self.num_stack, w)?;
+			write!(w, " ")?;
+		}
+
+		Ok(())
+	}
+
+	pub fn output(&self, d: &mut Data, w: &mut dyn Write) -> Result<()> {
+		write!(w, "function(")?;
+
+		write_in_order("param", self.num_param, w)?;
+
+		write!(w, ")")?;
+
+		for v in memory::visit(self) {
+			write!(w, "local memory_at_{0} = MEMORY_LIST[{0}]", v)?;
+		}
+
+		self.write_variable_list(w)?;
+
+		self.body.output(d, w)?;
+
+		write!(w, "end ")
+	}
+}

wasm/src/backend/visitor/data.rs

@@ -0,0 +1,59 @@
+use crate::backend::ast::data::{
+	AnyBinOp, AnyLoad, AnyStore, AnyUnOp, Backward, Br, BrIf, BrTable, Call, CallIndirect,
+	Expression, Forward, GetGlobal, GetLocal, If, Memorize, MemoryGrow, MemorySize, Return, Select,
+	SetGlobal, SetLocal, Statement, Value,
+};
+
+pub trait Visitor {
+	fn visit_recall(&mut self, _: usize) {}
+
+	fn visit_select(&mut self, _: &Select) {}
+
+	fn visit_get_local(&mut self, _: &GetLocal) {}
+
+	fn visit_get_global(&mut self, _: &GetGlobal) {}
+
+	fn visit_any_load(&mut self, _: &AnyLoad) {}
+
+	fn visit_memory_size(&mut self, _: &MemorySize) {}
+
+	fn visit_memory_grow(&mut self, _: &MemoryGrow) {}
+
+	fn visit_value(&mut self, _: &Value) {}
+
+	fn visit_any_unop(&mut self, _: &AnyUnOp) {}
+
+	fn visit_any_binop(&mut self, _: &AnyBinOp) {}
+
+	fn visit_expression(&mut self, _: &Expression) {}
+
+	fn visit_unreachable(&mut self) {}
+
+	fn visit_memorize(&mut self, _: &Memorize) {}
+
+	fn visit_forward(&mut self, _: &Forward) {}
+
+	fn visit_backward(&mut self, _: &Backward) {}
+
+	fn visit_if(&mut self, _: &If) {}
+
+	fn visit_br(&mut self, _: &Br) {}
+
+	fn visit_br_if(&mut self, _: &BrIf) {}
+
+	fn visit_br_table(&mut self, _: &BrTable) {}
+
+	fn visit_return(&mut self, _: &Return) {}
+
+	fn visit_call(&mut self, _: &Call) {}
+
+	fn visit_call_indirect(&mut self, _: &CallIndirect) {}
+
+	fn visit_set_local(&mut self, _: &SetLocal) {}
+
+	fn visit_set_global(&mut self, _: &SetGlobal) {}
+
+	fn visit_any_store(&mut self, _: &AnyStore) {}
+
+	fn visit_statement(&mut self, _: &Statement) {}
+}

wasm/src/backend/visitor/localize.rs

@@ -0,0 +1,53 @@
+use std::collections::BTreeSet;
+
+use crate::backend::ast::data::{AnyBinOp, AnyLoad, AnyStore, AnyUnOp, Function};
+
+use super::data::Visitor;
+
+struct Visit {
+	result: BTreeSet<(&'static str, &'static str)>,
+}
+
+impl Visitor for Visit {
+	fn visit_any_load(&mut self, v: &AnyLoad) {
+		let name = v.op.as_name();
+
+		self.result.insert(("load", name));
+	}
+
+	fn visit_any_store(&mut self, v: &AnyStore) {
+		let name = v.op.as_name();
+
+		self.result.insert(("store", name));
+	}
+
+	fn visit_any_unop(&mut self, v: &AnyUnOp) {
+		if v.op.as_operator().is_some() {
+			return;
+		}
+
+		let name = v.op.as_name();
+
+		self.result.insert(name);
+	}
+
+	fn visit_any_binop(&mut self, v: &AnyBinOp) {
+		if v.op.as_operator().is_some() {
+			return;
+		}
+
+		let name = v.op.as_name();
+
+		self.result.insert(name);
+	}
+}
+
+pub fn visit(func: &Function) -> BTreeSet<(&'static str, &'static str)> {
+	let mut visit = Visit {
+		result: BTreeSet::new(),
+	};
+
+	func.accept(&mut visit);
+
+	visit.result
+}

wasm/src/backend/visitor/memory.rs

@@ -0,0 +1,37 @@
+use std::collections::BTreeSet;
+
+use crate::backend::ast::data::{AnyLoad, AnyStore, Function, MemoryGrow, MemorySize};
+
+use super::data::Visitor;
+
+struct Visit {
+	result: BTreeSet<u8>,
+}
+
+impl Visitor for Visit {
+	fn visit_any_store(&mut self, _: &AnyStore) {
+		self.result.insert(0);
+	}
+
+	fn visit_any_load(&mut self, _: &AnyLoad) {
+		self.result.insert(0);
+	}
+
+	fn visit_memory_size(&mut self, m: &MemorySize) {
+		self.result.insert(m.memory);
+	}
+
+	fn visit_memory_grow(&mut self, m: &MemoryGrow) {
+		self.result.insert(m.memory);
+	}
+}
+
+pub fn visit(func: &Function) -> BTreeSet<u8> {
+	let mut visit = Visit {
+		result: BTreeSet::new(),
+	};
+
+	func.accept(&mut visit);
+
+	visit.result
+}

wasm/src/backend/visitor/mod.rs

@@ -0,0 +1,3 @@
+pub mod data;
+pub mod localize;
+pub mod memory;