diff --git a/dust-lang/src/chunk.rs b/dust-lang/src/chunk.rs index 294d3f2..e8b25a9 100644 --- a/dust-lang/src/chunk.rs +++ b/dust-lang/src/chunk.rs @@ -62,8 +62,10 @@ impl Chunk { self.instructions.push((instruction, position)); } - pub fn pop_instruction(&mut self) -> Option<(Instruction, Span)> { - self.instructions.pop() + pub fn pop_instruction(&mut self, position: Span) -> Result<(Instruction, Span), ChunkError> { + self.instructions + .pop() + .ok_or(ChunkError::InstructionUnderflow { position }) } pub fn get_constant(&self, index: usize, position: Span) -> Result<&Value, ChunkError> { @@ -207,10 +209,7 @@ impl Display for Chunk { write!( f, "{}", - self.disassembler("Chunk Display") - .styled() - .width(80) - .disassemble() + self.disassembler("Chunk Display").styled().disassemble() ) } } @@ -260,42 +259,65 @@ pub struct ChunkDisassembler<'a> { } impl<'a> ChunkDisassembler<'a> { + const INSTRUCTION_HEADER: [&'static str; 5] = [ + "", + "Instructions", + "------------", + "OFFSET OPERATION INFO POSITION", + "------- -------------- -------------------- --------", + ]; + + const CONSTANT_HEADER: [&'static str; 5] = [ + "", + "Constants", + "---------", + "INDEX KIND VALUE", + "----- ----- -----", + ]; + + const LOCAL_HEADER: [&'static str; 5] = [ + "", + "Locals", + "------", + "INDEX IDENTIFIER DEPTH KIND VALUE", + "----- ---------- ----- ----- -----", + ]; + + /// The default width of the disassembly output. To correctly align the output, this should be + /// set to the width of the longest line that the disassembler is guaranteed to produce. + const DEFAULT_WIDTH: usize = Self::INSTRUCTION_HEADER[3].len() + 1; + pub fn new(name: &'a str, chunk: &'a Chunk) -> Self { Self { name, chunk, - width: 0, + width: Self::DEFAULT_WIDTH, styled: false, } } pub fn disassemble(&self) -> String { - let mut disassembled = String::new(); - let mut push_centered_line = |section: &str| { - let width = self.width; - let is_header = section.contains('\n'); + let chunk_header = self.chunk_header(); + let mut disassembled = String::with_capacity(self.predict_capacity()); - if is_header && self.styled { - disassembled.push('\n'); + println!("capactity: {}", disassembled.capacity()); - for line in section.lines() { - if line.is_empty() { - continue; - } - - let centered = format!("{:^width$}\n", line.bold()); - - disassembled.push_str(¢ered); - } + let center = |line: &str| format!("{line:^width$}\n", width = self.width); + let style = |line: String| { + if self.styled { + line.bold().to_string() } else { - let centered = format!("{section:^width$}\n"); - - disassembled.push_str(¢ered); + line } }; - push_centered_line(&self.name_header()); - push_centered_line(self.instructions_header()); + for line in chunk_header.iter() { + disassembled.push_str(&style(center(line))); + } + + for line in Self::INSTRUCTION_HEADER { + disassembled.push_str(&style(center(line))); + } for (offset, (instruction, position)) in self.chunk.instructions.iter().enumerate() { let position = position.to_string(); @@ -307,17 +329,18 @@ impl<'a> ChunkDisassembler<'a> { format!("{offset:<7} {operation:14} {:20} {position:8}", " ") }; - push_centered_line(&instruction_display); + disassembled.push_str(¢er(&instruction_display)); } - push_centered_line(Self::constant_header()); + for line in Self::CONSTANT_HEADER { + disassembled.push_str(&style(center(line))); + } for (index, value_option) in self.chunk.constants.iter().enumerate() { - let value_kind_display = match value_option { - Some(Value::Raw(_)) => "RAW", - Some(Value::Reference(_)) => "REF", - Some(Value::Mutable(_)) => "MUT", - None => "EMPTY", + let value_kind_display = if let Some(value) = value_option { + value.kind().to_string() + } else { + "empty".to_string() }; let value_display = value_option .as_ref() @@ -325,27 +348,28 @@ impl<'a> ChunkDisassembler<'a> { .unwrap_or_else(|| "EMPTY".to_string()); let constant_display = format!("{index:<5} {value_kind_display:<5} {value_display:<5}"); - push_centered_line(&constant_display); + disassembled.push_str(¢er(&constant_display)); } - push_centered_line(Self::local_header()); + for line in Self::LOCAL_HEADER { + disassembled.push_str(&style(center(line))); + } for ( index, Local { identifier, depth, - value, + value: value_option, }, ) in self.chunk.locals.iter().enumerate() { - let value_kind_display = match value { - Some(Value::Raw(_)) => "RAW", - Some(Value::Reference(_)) => "REF", - Some(Value::Mutable(_)) => "MUT", - None => "EMPTY", + let value_kind_display = if let Some(value) = value_option { + value.kind().to_string() + } else { + "empty".to_string() }; - let value_display = value + let value_display = value_option .as_ref() .map(|value| value.to_string()) .unwrap_or_else(|| "EMPTY".to_string()); @@ -353,9 +377,11 @@ impl<'a> ChunkDisassembler<'a> { let local_display = format!("{index:<5} {identifier_display:<10} {depth:<5} {value_kind_display:<4} {value_display:<5}"); - push_centered_line(&local_display); + disassembled.push_str(¢er(&local_display)); } + println!("length: {}", disassembled.len()); + disassembled } @@ -371,31 +397,38 @@ impl<'a> ChunkDisassembler<'a> { self } - fn name_header(&self) -> String { - let name_length = self.name.len(); - - format!("\n{}\n{}\n", self.name, "=".repeat(name_length)) + fn chunk_header(&self) -> [String; 3] { + [ + self.name.to_string(), + "=".repeat(self.name.len()), + format!( + "{} instructions, {} constants, {} locals", + self.chunk.instructions.len(), + self.chunk.constants.len(), + self.chunk.locals.len() + ), + ] } - fn instructions_header(&self) -> &'static str { - "\nInstructions\n\ - ------------\n\ - OFFSET OPERATION INFO POSITION\n\ - ------- -------------- -------------------- --------\n" - } + /// Predicts the capacity of the disassembled output. This is used to pre-allocate the string + /// buffer to avoid reallocations. + /// + /// The capacity is calculated as follows: + /// - Get the number of static lines, i.e. lines that are always present in the disassembly + /// - Get the number of dynamic lines, i.e. lines that are generated from the chunk + /// - Add 1 to the width to account for the newline character + /// - Multiply the total number of lines by the width of the disassembly output + fn predict_capacity(&self) -> usize { + let chunk_header_line_count = 3; // self.chunk_header().len() is hard-coded to 3 + let static_line_count = chunk_header_line_count + + Self::INSTRUCTION_HEADER.len() + + Self::CONSTANT_HEADER.len() + + Self::LOCAL_HEADER.len(); + let dynamic_line_count = + self.chunk.instructions.len() + self.chunk.constants.len() + self.chunk.locals.len(); + let total_line_count = static_line_count + dynamic_line_count; - fn constant_header() -> &'static str { - "\nConstants\n\ - ---------\n\ - INDEX KIND VALUE\n\ - ----- ----- -----\n" - } - - fn local_header() -> &'static str { - "\nLocals\n\ - ------\n\ - INDEX IDENTIFIER DEPTH KIND VALUE\n\ - ----- ---------- ----- ----- -----\n" + total_line_count * (self.width + 1) } } @@ -416,6 +449,9 @@ pub enum ChunkError { index: usize, position: Span, }, + InstructionUnderflow { + position: Span, + }, LocalIndexOutOfBounds { index: usize, position: Span, @@ -440,6 +476,7 @@ impl AnnotatedError for ChunkError { ChunkError::ConstantAlreadyUsed { .. } => "Constant already used", ChunkError::ConstantOverflow { .. } => "Constant overflow", ChunkError::ConstantIndexOutOfBounds { .. } => "Constant index out of bounds", + ChunkError::InstructionUnderflow { .. } => "Instruction underflow", ChunkError::LocalIndexOutOfBounds { .. } => "Identifier index out of bounds", ChunkError::IdentifierOverflow { .. } => "Identifier overflow", ChunkError::IdentifierNotFound { .. } => "Identifier not found", @@ -455,6 +492,7 @@ impl AnnotatedError for ChunkError { ChunkError::ConstantIndexOutOfBounds { index, .. } => { Some(format!("Constant index: {}", index)) } + ChunkError::InstructionUnderflow { .. } => None, ChunkError::LocalIndexOutOfBounds { index, .. } => { Some(format!("Identifier index: {}", index)) } diff --git a/dust-lang/src/parser/mod.rs b/dust-lang/src/parser/mod.rs index 605143b..2d7344d 100644 --- a/dust-lang/src/parser/mod.rs +++ b/dust-lang/src/parser/mod.rs @@ -255,47 +255,39 @@ impl<'src> Parser<'src> { self.parse(rule.precedence.increment())?; - let previous_instruction = self.chunk.pop_instruction(); + let (previous_instruction, position) = self.chunk.pop_instruction(self.current_position)?; let right_register = match previous_instruction { - Some(( - Instruction { - operation: Operation::LoadConstant, - arguments, - .. - }, - _, - )) => { + Instruction { + operation: Operation::LoadConstant, + arguments, + .. + } => { self.decrement_register()?; arguments[0] } - Some((instruction, position)) => { - self.chunk.push_instruction(instruction, position); + _ => { + self.chunk.push_instruction(previous_instruction, position); self.current_register - 1 } - _ => self.current_register - 1, }; - let previous_instruction = self.chunk.pop_instruction(); + let (previous_instruction, position) = self.chunk.pop_instruction(self.current_position)?; let left_register = match previous_instruction { - Some(( - Instruction { - operation: Operation::LoadConstant, - arguments, - .. - }, - _, - )) => { + Instruction { + operation: Operation::LoadConstant, + arguments, + .. + } => { self.decrement_register()?; arguments[0] } - Some((instruction, position)) => { - self.chunk.push_instruction(instruction, position); + _ => { + self.chunk.push_instruction(previous_instruction, position); self.current_register - 2 } - _ => self.current_register - 2, }; let instruction = match operator { TokenKind::Plus => { @@ -449,17 +441,17 @@ impl<'src> Parser<'src> { self.expect(TokenKind::Equal)?; self.parse_expression()?; - let local_index = self.chunk.declare_local(identifier, position)?; - let previous_instruction = self.chunk.pop_instruction(); + let local_index = self + .chunk + .declare_local(identifier, self.current_position)?; + let (previous_instruction, previous_position) = + self.chunk.pop_instruction(self.current_position)?; - if let Some(( - Instruction { - operation: Operation::GetLocal, - destination, - arguments, - }, - _, - )) = previous_instruction + if let Instruction { + operation: Operation::GetLocal, + destination, + arguments, + } = previous_instruction { self.emit_instruction( Instruction { @@ -469,13 +461,9 @@ impl<'src> Parser<'src> { }, position, ); - } else if let Some((instruction, position)) = previous_instruction { - self.chunk.push_instruction(instruction, position); } else { - return Err(ParseError::ExpectedExpression { - found: self.previous_token.to_owned(), - position: self.previous_position, - }); + self.chunk + .push_instruction(previous_instruction, previous_position); } self.emit_instruction( diff --git a/dust-lang/src/value.rs b/dust-lang/src/value.rs index 3817c48..c4ec211 100644 --- a/dust-lang/src/value.rs +++ b/dust-lang/src/value.rs @@ -1,4 +1,36 @@ //! Dust value representation +//! +//! # Examples +//! +//! Each type of value has a corresponding method for instantiation: +//! +//! ``` +//! # use dust_lang::Value; +//! let boolean = Value::boolean(true); +//! let float = Value::float(3.14); +//! let integer = Value::integer(42); +//! let string = Value::string("Hello, world!"); +//! ``` +//! +//! Values can be combined into more complex values: +//! +//! ``` +//! # use dust_lang::Value; +//! let list = Value::list(vec![ +//! Value::integer(1), +//! Value::integer(2), +//! Value::integer(3), +//! ]); +//! ``` +//! +//! Values have a type, which can be retrieved using the `r#type` method: +//! +//! ``` +//! # use dust_lang::*; +//! let value = Value::integer(42); +//! +//! assert_eq!(value.r#type(), Type::Integer); +//! ``` use std::{ cmp::Ordering, collections::HashMap, @@ -17,35 +49,7 @@ use crate::{EnumType, FunctionType, Identifier, RangeableType, StructType, Type} /// Dust value representation /// -/// Each type of value has a corresponding constructor, here are some simple examples: -/// -/// ``` -/// # use dust_lang::Value; -/// let boolean = Value::boolean(true); -/// let float = Value::float(3.14); -/// let integer = Value::integer(42); -/// let string = Value::string("Hello, world!"); -/// ``` -/// -/// Values can be combined into more complex values: -/// -/// ``` -/// # use dust_lang::Value; -/// let list = Value::list(vec![ -/// Value::integer(1), -/// Value::integer(2), -/// Value::integer(3), -/// ]); -/// ``` -/// -/// Values have a type, which can be retrieved using the `type` method: -/// -/// ``` -/// # use dust_lang::*; -/// let value = Value::integer(42); -/// -/// assert_eq!(value.r#type(), Type::Integer); -/// ``` +/// See the [module-level documentation][self] for more. #[derive(Debug)] pub enum Value { Raw(ValueData), @@ -114,14 +118,6 @@ impl Value { } } - pub fn into_mutable(self) -> Self { - match self { - Value::Raw(data) => Value::Mutable(Arc::new(RwLock::new(data))), - Value::Reference(data) => Value::Mutable(Arc::new(RwLock::new(data.as_ref().clone()))), - Value::Mutable(_) => self, - } - } - pub fn into_raw(self) -> Self { match self { Value::Raw(_) => self, @@ -142,6 +138,14 @@ impl Value { } } + pub fn into_mutable(self) -> Self { + match self { + Value::Raw(data) => Value::Mutable(Arc::new(RwLock::new(data))), + Value::Reference(data) => Value::Mutable(Arc::new(RwLock::new(data.as_ref().clone()))), + Value::Mutable(_) => self, + } + } + pub fn clone_data(&self) -> ValueData { match self { Value::Raw(data) => data.clone(), @@ -734,6 +738,14 @@ impl Value { .ok_or_else(|| ValueError::CannotOr(self.clone(), other.clone())) .map(Value::Raw) } + + pub fn kind(&self) -> ValueKind { + match self { + Value::Raw(_) => ValueKind::Raw, + Value::Reference(_) => ValueKind::Reference, + Value::Mutable(_) => ValueKind::Mutable, + } + } } impl Display for Value { @@ -928,6 +940,23 @@ impl<'de> Deserialize<'de> for Value { } } +#[derive(Clone, Debug)] +pub enum ValueKind { + Raw, + Reference, + Mutable, +} + +impl Display for ValueKind { + fn fmt(&self, f: &mut Formatter) -> fmt::Result { + match self { + ValueKind::Raw => write!(f, "raw"), + ValueKind::Reference => write!(f, "reference"), + ValueKind::Mutable => write!(f, "mutable"), + } + } +} + #[derive(Clone, Debug)] pub enum ValueData { Boolean(bool), diff --git a/dust-shell/src/main.rs b/dust-shell/src/main.rs index 9623fd9..c877bd8 100644 --- a/dust-shell/src/main.rs +++ b/dust-shell/src/main.rs @@ -60,14 +60,7 @@ fn main() { fn parse_and_display_errors(source: &str) { match parse(source) { - Ok(chunk) => println!( - "{}", - chunk - .disassembler("Dust CLI Input") - .styled() - .width(80) - .disassemble() - ), + Ok(chunk) => println!("{}", chunk.disassembler("Dust CLI Input").disassemble()), Err(error) => { eprintln!("{}", error.report()); }