Continue refactor; Condense registers in logic chains

dust-lang/src/compiler/mod.rs

@@ -610,11 +610,12 @@ impl<'src> Compiler<'src> {
         &mut self,
         instruction: &Instruction,
     ) -> Result<(Argument, bool), CompileError> {
-        let argument = instruction.destination_as_argument().ok_or_else(|| {
+        let argument =
-            CompileError::ExpectedExpression {
+            instruction
+                .as_argument()
+                .ok_or_else(|| CompileError::ExpectedExpression {
                     found: self.previous_token.to_owned(),
                     position: self.previous_position,
-            }
                 })?;
         let push_back = matches!(argument, Argument::Register(_));
 
@@ -867,7 +868,20 @@ impl<'src> Compiler<'src> {
             self.get_last_operations(),
             Some([Operation::Test, Operation::Jump, _])
         );
-        let (left_instruction, left_type, left_position) = self.pop_last_instruction()?;
+
+        let (mut left_instruction, left_type, left_position) = self.pop_last_instruction()?;
+
+        if is_logic_chain {
+            let destination = self
+                .instructions
+                .iter()
+                .rev()
+                .nth(2)
+                .map_or(0, |(instruction, _, _)| instruction.a);
+
+            left_instruction.a = destination;
+        }
+
         let jump_index = self.instructions.len().saturating_sub(1);
         let mut jump_distance = if is_logic_chain {
             self.instructions.pop().map_or(0, |(jump, _, _)| {
@@ -886,13 +900,10 @@ impl<'src> Compiler<'src> {
             });
         }
 
-        let (argument, push_back) = self.handle_binary_argument(&left_instruction)?;
+        let (left, _) = self.handle_binary_argument(&left_instruction)?;
-        let is_local = left_instruction.operation() == Operation::GetLocal;
 
-        if push_back || is_local {
         self.instructions
             .push((left_instruction, left_type.clone(), left_position));
-        }
 
         let operator = self.current_token;
         let operator_position = self.current_position;
@@ -908,16 +919,16 @@ impl<'src> Compiler<'src> {
                 })
             }
         };
-        let test = Instruction::from(Test {
+        let test = Instruction::test(left, test_boolean);
-            argument,
-            test_value: test_boolean,
-        });
 
         self.advance()?;
         self.emit_instruction(test, Type::None, operator_position);
         self.emit_instruction(Instruction::jump(1, true), Type::None, operator_position);
         self.parse_sub_expression(&rule.precedence)?;
 
+        let (mut right_instruction, _, _) = self.instructions.last_mut().unwrap();
+        right_instruction.a = left_instruction.a;
+
         if is_logic_chain {
             let expression_length = self.instructions.len() - jump_index - 1;
             jump_distance += expression_length as u8;
@@ -992,7 +1003,7 @@ impl<'src> Compiler<'src> {
             });
 
             self.emit_instruction(set_local, Type::None, start_position);
-            optimize_set_local(self);
+            optimize_set_local(self)?;
 
             return Ok(());
         }
@@ -1092,7 +1103,7 @@ impl<'src> Compiler<'src> {
         self.parse_expression()?;
 
         if let Some((instruction, _, _)) = self.instructions.last() {
-            let argument = match instruction.destination_as_argument() {
+            let argument = match instruction.as_argument() {
                 Some(argument) => argument,
                 None => {
                     return Err(CompileError::ExpectedExpression {
@@ -1323,7 +1334,18 @@ impl<'src> Compiler<'src> {
     }
 
     fn parse_sub_expression(&mut self, precedence: &Precedence) -> Result<(), CompileError> {
-        self.parse(precedence.increment())
+        self.parse(precedence.increment())?;
+
+        let expression_type = self.get_last_instruction_type();
+
+        if expression_type == Type::None || self.instructions.is_empty() {
+            return Err(CompileError::ExpectedExpression {
+                found: self.previous_token.to_owned(),
+                position: self.current_position,
+            });
+        }
+
+        Ok(())
     }
 
     fn parse_return_statement(&mut self) -> Result<(), CompileError> {
@@ -1572,11 +1594,12 @@ impl<'src> Compiler<'src> {
             });
         }
 
-        let function = last_instruction.destination_as_argument().ok_or_else(|| {
+        let function =
-            CompileError::ExpectedExpression {
+            last_instruction
+                .as_argument()
+                .ok_or_else(|| CompileError::ExpectedExpression {
                     found: self.previous_token.to_owned(),
                     position: self.previous_position,
-            }
                 })?;
         let register_type = self.get_register_type(function.index())?;
         let function_return_type = match register_type {

dust-lang/src/compiler/optimize.rs

@@ -1,7 +1,5 @@
 //! Tools used by the compiler to optimize a chunk's bytecode.
 
-use smallvec::SmallVec;
-
 use crate::{instruction::SetLocal, CompileError, Compiler, Instruction, Operation, Span, Type};
 
 fn get_last_operations<const COUNT: usize>(

dust-lang/src/instruction/mod.rs

@@ -40,15 +40,15 @@
 //! write, this ensures that the instruction has the correct flags to represent the arguments.
 //!
 //! ```
-//! # use dust_lang::instruction::{Instruction, Add, u8, Argument};
+//! # use dust_lang::instruction::{Instruction, Add, Argument};
 //! let add_1 = Instruction::add(
-//!     u8::Register(0),
+//!     0,
-//!     Argument::Local(1),
+//!     Argument::Register(1),
 //!     Argument::Constant(2)
 //! );
 //! let add_2 = Instruction::from(Add {
-//!     destination: u8::Register(0),
+//!     destination: 0,
-//!     left: Argument::Local(1),
+//!     left: Argument::Register(1),
 //!     right: Argument::Constant(2),
 //! });
 //!
@@ -57,21 +57,20 @@
 //!
 //! ## Reading Instructions
 //!
-//! To read an instruction, check its `operation` field, then convert the instruction to the struct
+//! To read an instruction, check its operation with [`Instruction::operation`], then convert the
-//! that corresponds to that operation. Like the example above, this removes the burden of dealing
+//! instruction to the struct that corresponds to that operation. Like the example above, this
-//! with the options and handles the process of reading the options and the instruction's fields
+//! removes the burden of dealing with the options directly and automatically casts the A, B, C and
-//! into `u8` or `Argument` enums when appropriate.
+//! D fields as `u8`, `bool` or `Argument` values.
 //!
 //! ```
-//! # use dust_lang::instruction::{Instruction, Add, u8, Argument, Operation};
+//! # use dust_lang::instruction::{Instruction, Add, Argument, Operation};
 //! # let mystery_instruction = Instruction::add(
-//!     u8::Local(1),
+//! #     1,
-//!     Argument::Local(1),
+//! #     Argument::Register(1),
-//!     Argument::Constant(2)
+//! #     Argument::Constant(2)
-//! );
+//! # );
-//!
+//! // Let's read an instruction and see if it performs addition-assignment,
-//! // Let's read an instruction and see if it performs addition-assignment, like in one of the
+//! // like in one of the following examples:
-//! // following examples:
 //! //  - `a += 2`
 //! //  - `a = a + 2`
 //! //  - `a = 2 + a`
@@ -79,7 +78,7 @@
 //! let operation = mystery_instruction.operation();
 //!
 //! match operation {
-//!     Operation::ADD => {
+//!     Operation::Add => {
 //!         let Add { destination, left, right } = Add::from(&mystery_instruction);
 //!         let is_add_assign =
 //!             left == Argument::Register(destination)
@@ -87,10 +86,7 @@
 //!
 //!         assert!(is_add_assign);
 //!     }
-//!     // Handle other operations...
+//!     _ => {} // Handle other operations...
-//!     _ => {
-//!         panic!("Unknown operation code: {operation}");
-//!     }
 //! }
 //! ```
 mod add;
@@ -357,7 +353,7 @@ impl Instruction {
         })
     }
 
-    pub fn destination_as_argument(&self) -> Option<Argument> {
+    pub fn as_argument(&self) -> Option<Argument> {
         match self.operation() {
             Operation::LoadConstant => Some(Argument::Constant(self.b)),
             Operation::LoadBoolean
@@ -592,7 +588,7 @@ impl Instruction {
                 } = Less::from(self);
                 let comparison_symbol = if value { "<" } else { ">=" };
 
-                format!("R{destination} {left} {comparison_symbol} {right}")
+                format!("R{destination} = {left} {comparison_symbol} {right}")
             }
             Operation::LessEqual => {
                 let LessEqual {
@@ -603,7 +599,7 @@ impl Instruction {
                 } = LessEqual::from(self);
                 let comparison_symbol = if value { "<=" } else { ">" };
 
-                format!("R{destination} {left} {comparison_symbol} {right}")
+                format!("R{destination} = {left} {comparison_symbol} {right}")
             }
             Operation::Negate => {
                 let Negate {
@@ -687,7 +683,7 @@ impl Debug for Instruction {
     }
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, PartialOrd, Ord)]
 pub enum Argument {
     Constant(u8),
     Register(u8),
@@ -740,15 +736,15 @@ mod tests {
     use super::*;
 
     #[test]
-    fn instruction_is_8_bytes() {
+    fn instruction_is_4_bytes() {
-        assert_eq!(size_of::<Instruction>(), 8);
+        assert_eq!(size_of::<Instruction>(), 4);
     }
 
     #[test]
     fn instruction_layout() {
-        assert_eq!(offset_of!(Instruction, a), 0);
+        assert_eq!(offset_of!(Instruction, metadata), 0);
-        assert_eq!(offset_of!(Instruction, b), 1);
+        assert_eq!(offset_of!(Instruction, a), 1);
-        assert_eq!(offset_of!(Instruction, c), 2);
+        assert_eq!(offset_of!(Instruction, b), 2);
-        assert_eq!(offset_of!(Instruction, metadata), 3);
+        assert_eq!(offset_of!(Instruction, c), 3);
     }
 }

dust-lang/src/scope.rs

@@ -47,6 +47,6 @@ impl Scope {
 
 impl Display for Scope {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        write!(f, "({}, {})", self.depth, self.block_index)
+        write!(f, "{}.{}", self.depth, self.block_index)
     }
 }

dust-lang/src/value/abstract_value.rs

@@ -24,7 +24,7 @@ impl AbstractValue {
                 let mut resolved_items = Vec::with_capacity(items.len());
 
                 for pointer in items {
-                    let resolved_item = vm.follow_pointer(*pointer)?.to_concrete_owned(vm)?;
+                    let resolved_item = vm.follow_pointer(*pointer)?.into_concrete_owned(vm)?;
 
                     resolved_items.push(resolved_item);
                 }

dust-lang/src/value/mod.rs

@@ -25,10 +25,10 @@ impl Value {
         }
     }
 
-    pub fn to_concrete_owned(&self, vm: &Vm) -> Result<ConcreteValue, VmError> {
+    pub fn into_concrete_owned(self, vm: &Vm) -> Result<ConcreteValue, VmError> {
         match self {
             Value::Abstract(abstract_value) => abstract_value.to_concrete_owned(vm),
-            Value::Concrete(concrete_value) => Ok(concrete_value.clone()),
+            Value::Concrete(concrete_value) => Ok(concrete_value),
         }
     }
 
@@ -64,10 +64,10 @@ impl ValueRef<'_> {
         }
     }
 
-    pub fn to_concrete_owned(&self, vm: &Vm) -> Result<ConcreteValue, VmError> {
+    pub fn into_concrete_owned(self, vm: &Vm) -> Result<ConcreteValue, VmError> {
         match self {
             ValueRef::Abstract(abstract_value) => abstract_value.to_concrete_owned(vm),
-            ValueRef::Concrete(concrete_value) => Ok((*concrete_value).clone()),
+            ValueRef::Concrete(concrete_value) => Ok(concrete_value.clone()),
         }
     }
 

dust-lang/src/vm.rs

@@ -169,7 +169,7 @@ impl<'a> Vm<'a> {
                     let local_register_index = self.get_local_register(local_index)?;
                     let register = Register::Pointer(Pointer::Stack(register_index));
 
-                    self.set_register(local_register_index, register);
+                    self.set_register(local_register_index, register)?;
                 }
                 Operation::Add => {
                     let Add {
@@ -471,7 +471,7 @@ impl<'a> Vm<'a> {
                         self.chunk
                     } else {
                         return Err(VmError::ExpectedFunction {
-                            found: function.to_concrete_owned(self)?,
+                            found: function.into_concrete_owned(self)?,
                             position: self.current_position(),
                         });
                     };
@@ -521,7 +521,7 @@ impl<'a> Vm<'a> {
                     return if let Some(register_index) = self.last_assigned_register {
                         let return_value = self
                             .open_register(register_index)?
-                            .to_concrete_owned(self)?;
+                            .into_concrete_owned(self)?;
 
                         Ok(Some(return_value))
                     } else {