2107 lines
67 KiB
Rust
2107 lines
67 KiB
Rust
//! Parsing tools and errors
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//!
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//! This module provides two lexing options:
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//! - [`parse`], which parsers the entire input and returns a chunk
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//! - [`Parser`], which parsers the input a token at a time while assembling a chunk
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use std::{
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fmt::{self, Display, Formatter},
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mem::replace,
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num::{ParseFloatError, ParseIntError},
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vec,
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};
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use colored::Colorize;
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use serde::{Deserialize, Serialize};
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use crate::{
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AnnotatedError, Chunk, DustError, FunctionType, Instruction, LexError, Lexer, Local,
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NativeFunction, Operation, Scope, Span, Token, TokenKind, TokenOwned, Type, Value,
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};
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/// Parses the input and returns a chunk.
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///
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/// # Example
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///
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/// ```
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/// # use dust_lang::parse;
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/// let source = "40 + 2 == 42";
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/// let chunk = parse(source).unwrap();
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///
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/// assert_eq!(chunk.len(), 6);
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/// ```
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pub fn parse(source: &str) -> Result<Chunk, DustError> {
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let lexer = Lexer::new(source);
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let mut parser = Parser::new(lexer).map_err(|error| DustError::Parse { error, source })?;
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parser
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.parse_top_level()
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.map_err(|error| DustError::Parse { error, source })?;
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Ok(parser.finish())
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}
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/// Low-level tool for parsing the input a token at a time while assembling a chunk.
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///
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/// See the [`parse`] function an example of how to create and use a Parser.
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#[derive(Debug, Clone, Eq, PartialEq, PartialOrd, Ord, Serialize)]
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struct Parser<'src> {
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lexer: Lexer<'src>,
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chunk: Chunk,
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current_is_expression: bool,
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minimum_register: u8,
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current_token: Token<'src>,
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current_position: Span,
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previous_token: Token<'src>,
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previous_position: Span,
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}
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impl<'src> Parser<'src> {
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pub fn new(mut lexer: Lexer<'src>) -> Result<Self, ParseError> {
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let (current_token, current_position) = lexer.next_token()?;
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log::info!(
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"Begin chunk with {} at {}",
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current_token.to_string().bold(),
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current_position.to_string()
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);
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Ok(Parser {
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lexer,
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chunk: Chunk::new(None),
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current_is_expression: false,
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minimum_register: 0,
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current_token,
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current_position,
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previous_token: Token::Eof,
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previous_position: Span(0, 0),
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})
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}
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pub fn finish(self) -> Chunk {
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log::info!("End chunk");
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self.chunk
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}
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fn is_eof(&self) -> bool {
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matches!(self.current_token, Token::Eof)
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}
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fn next_register(&mut self) -> u8 {
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self.chunk
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.instructions()
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.iter()
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.rev()
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.find_map(|(instruction, _)| {
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if instruction.yields_value() {
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Some(instruction.a() + 1)
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} else {
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None
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}
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})
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.unwrap_or(self.minimum_register)
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}
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fn advance(&mut self) -> Result<(), ParseError> {
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if self.is_eof() {
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return Ok(());
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}
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let (new_token, position) = self.lexer.next_token()?;
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log::info!(
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"Parsing {} at {}",
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new_token.to_string().bold(),
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position.to_string()
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);
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self.previous_token = replace(&mut self.current_token, new_token);
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self.previous_position = replace(&mut self.current_position, position);
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Ok(())
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}
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fn get_local(&self, index: u8) -> Result<&Local, ParseError> {
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let index = index as usize;
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self.chunk
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.locals()
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.get(index)
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.ok_or(ParseError::LocalIndexOutOfBounds {
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index,
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position: self.current_position,
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})
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}
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fn get_local_index(&self, identifier_text: &str) -> Result<u8, ParseError> {
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self.chunk
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.locals()
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.iter()
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.enumerate()
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.rev()
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.find_map(|(index, local)| {
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let identifier = self
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.chunk
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.constants()
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.get(local.identifier_index as usize)?
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.as_string()?;
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if identifier == identifier_text {
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Some(index as u8)
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} else {
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None
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}
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})
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.ok_or(ParseError::UndeclaredVariable {
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identifier: identifier_text.to_string(),
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position: self.current_position,
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})
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}
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pub fn declare_local(
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&mut self,
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identifier: &str,
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r#type: Option<Type>,
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is_mutable: bool,
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scope: Scope,
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register_index: u8,
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) -> (u8, u8) {
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log::debug!("Declare local {identifier}");
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let identifier = Value::string(identifier);
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let identifier_index = self.chunk.push_or_get_constant(identifier);
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self.chunk.locals_mut().push(Local::new(
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identifier_index,
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r#type,
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is_mutable,
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scope,
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register_index,
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));
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(self.chunk.locals().len() as u8 - 1, identifier_index)
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}
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fn allow(&mut self, allowed: Token) -> Result<bool, ParseError> {
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if self.current_token == allowed {
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self.advance()?;
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Ok(true)
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} else {
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Ok(false)
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}
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}
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fn expect(&mut self, expected: Token) -> Result<(), ParseError> {
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if self.current_token == expected {
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self.advance()
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} else {
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Err(ParseError::ExpectedToken {
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expected: expected.kind(),
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found: self.current_token.to_owned(),
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position: self.current_position,
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})
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}
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}
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fn emit_instruction(&mut self, instruction: Instruction, position: Span) {
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log::debug!(
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"Emitting {} at {}",
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instruction.operation().to_string().bold(),
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position.to_string()
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);
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self.chunk.instructions_mut().push((instruction, position));
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}
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fn optimize_statement(&mut self) {
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if matches!(
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self.get_last_instructions(),
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Some([
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Operation::LoadBoolean | Operation::LoadConstant,
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Operation::LoadBoolean | Operation::LoadConstant,
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Operation::Jump,
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Operation::Equal | Operation::Less | Operation::LessEqual
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],)
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) {
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log::trace!("Optimizing boolean comparison");
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let mut instructions = self
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.chunk
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.instructions_mut()
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.iter_mut()
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.rev()
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.map(|(instruction, _)| instruction);
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let second_loader = instructions.next().unwrap();
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let first_loader = instructions.next().unwrap();
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first_loader.set_c_to_boolean(true);
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let mut second_loader_new = Instruction::with_operation(second_loader.operation());
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second_loader_new.set_a(first_loader.a());
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second_loader_new.set_b(second_loader.b());
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second_loader_new.set_c(second_loader.c());
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second_loader_new.set_b_to_boolean(second_loader.b_is_constant());
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second_loader_new.set_c_to_boolean(second_loader.c_is_constant());
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*second_loader = second_loader_new;
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}
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}
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fn pop_last_instruction(&mut self) -> Result<(Instruction, Span), ParseError> {
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self.chunk
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.instructions_mut()
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.pop()
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.ok_or_else(|| ParseError::ExpectedExpression {
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found: self.previous_token.to_owned(),
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position: self.previous_position,
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})
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}
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fn get_last_value_operation(&self) -> Option<Operation> {
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self.chunk
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.instructions()
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.iter()
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.last()
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.map(|(instruction, _)| instruction.operation())
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}
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fn get_last_instructions<const COUNT: usize>(&self) -> Option<[Operation; COUNT]> {
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let mut operations = [Operation::Return; COUNT];
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for (index, (instruction, _)) in self
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.chunk
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.instructions()
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.iter()
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.rev()
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.take(COUNT)
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.enumerate()
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{
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operations[index] = instruction.operation();
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}
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Some(operations)
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}
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fn get_last_jump_mut(&mut self) -> Option<&mut Instruction> {
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self.chunk
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.instructions_mut()
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.iter_mut()
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.find_map(|(instruction, _)| {
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if let Operation::Jump = instruction.operation() {
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Some(instruction)
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} else {
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None
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}
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})
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}
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fn get_last_jumpable_mut(&mut self) -> Option<&mut Instruction> {
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self.chunk
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.instructions_mut()
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.iter_mut()
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.find_map(|(instruction, _)| {
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if let Operation::LoadBoolean | Operation::LoadConstant = instruction.operation() {
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Some(instruction)
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} else {
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None
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}
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})
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}
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fn emit_constant(&mut self, value: Value, position: Span) -> Result<(), ParseError> {
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let constant_index = self.chunk.push_or_get_constant(value);
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let register = self.next_register();
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self.emit_instruction(
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Instruction::load_constant(register, constant_index, false),
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position,
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);
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Ok(())
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}
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fn parse_boolean(&mut self, _: Allowed) -> Result<(), ParseError> {
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let position = self.current_position;
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if let Token::Boolean(text) = self.current_token {
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self.advance()?;
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let boolean = text.parse::<bool>().unwrap();
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let register = self.next_register();
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self.emit_instruction(
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Instruction::load_boolean(register, boolean, false),
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position,
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);
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self.current_is_expression = true;
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Ok(())
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} else {
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Err(ParseError::ExpectedToken {
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expected: TokenKind::Boolean,
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found: self.current_token.to_owned(),
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position,
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})
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}
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}
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fn parse_byte(&mut self, _: Allowed) -> Result<(), ParseError> {
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let position = self.current_position;
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if let Token::Byte(text) = self.current_token {
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self.advance()?;
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let byte = u8::from_str_radix(&text[2..], 16)
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.map_err(|error| ParseError::ParseIntError { error, position })?;
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let value = Value::byte(byte);
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self.emit_constant(value, position)?;
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self.current_is_expression = true;
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Ok(())
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} else {
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Err(ParseError::ExpectedToken {
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expected: TokenKind::Byte,
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found: self.current_token.to_owned(),
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position,
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})
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}
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}
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fn parse_character(&mut self, _: Allowed) -> Result<(), ParseError> {
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let position = self.current_position;
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if let Token::Character(character) = self.current_token {
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self.advance()?;
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let value = Value::character(character);
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self.emit_constant(value, position)?;
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self.current_is_expression = true;
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Ok(())
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} else {
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Err(ParseError::ExpectedToken {
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expected: TokenKind::Character,
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found: self.current_token.to_owned(),
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position,
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})
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}
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}
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fn parse_float(&mut self, _: Allowed) -> Result<(), ParseError> {
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let position = self.current_position;
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if let Token::Float(text) = self.current_token {
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self.advance()?;
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let float = text
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.parse::<f64>()
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.map_err(|error| ParseError::ParseFloatError {
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error,
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position: self.previous_position,
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})?;
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let value = Value::float(float);
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self.emit_constant(value, position)?;
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self.current_is_expression = true;
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Ok(())
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} else {
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Err(ParseError::ExpectedToken {
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expected: TokenKind::Float,
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found: self.current_token.to_owned(),
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position,
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})
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}
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}
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fn parse_integer(&mut self, _: Allowed) -> Result<(), ParseError> {
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let position = self.current_position;
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if let Token::Integer(text) = self.current_token {
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self.advance()?;
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let integer = text
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.parse::<i64>()
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.map_err(|error| ParseError::ParseIntError {
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error,
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position: self.previous_position,
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})?;
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let value = Value::integer(integer);
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self.emit_constant(value, position)?;
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self.current_is_expression = true;
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Ok(())
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} else {
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Err(ParseError::ExpectedToken {
|
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expected: TokenKind::Integer,
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found: self.current_token.to_owned(),
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position,
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})
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}
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}
|
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|
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fn parse_string(&mut self, _: Allowed) -> Result<(), ParseError> {
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let position = self.current_position;
|
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|
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if let Token::String(text) = self.current_token {
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self.advance()?;
|
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let value = Value::string(text);
|
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self.emit_constant(value, position)?;
|
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self.current_is_expression = true;
|
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Ok(())
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} else {
|
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Err(ParseError::ExpectedToken {
|
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expected: TokenKind::String,
|
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found: self.current_token.to_owned(),
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position,
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})
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}
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}
|
|
|
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fn parse_grouped(&mut self, _: Allowed) -> Result<(), ParseError> {
|
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self.allow(Token::LeftParenthesis)?;
|
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self.parse_expression()?;
|
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self.expect(Token::RightParenthesis)?;
|
|
|
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self.current_is_expression = true;
|
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|
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Ok(())
|
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}
|
|
|
|
fn parse_unary(&mut self, _: Allowed) -> Result<(), ParseError> {
|
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let operator = self.current_token;
|
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let operator_position = self.current_position;
|
|
|
|
self.advance()?;
|
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self.parse_expression()?;
|
|
|
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let (previous_instruction, previous_position) = self.pop_last_instruction()?;
|
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let (push_back, is_constant, argument) = {
|
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match previous_instruction.operation() {
|
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Operation::GetLocal => (false, false, previous_instruction.a()),
|
|
Operation::LoadConstant => (false, true, previous_instruction.a()),
|
|
Operation::LoadBoolean => (true, false, previous_instruction.a()),
|
|
Operation::Close => {
|
|
return Err(ParseError::ExpectedExpression {
|
|
found: self.previous_token.to_owned(),
|
|
position: self.previous_position,
|
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});
|
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}
|
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_ => (true, false, previous_instruction.a()),
|
|
}
|
|
};
|
|
|
|
if push_back {
|
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self.emit_instruction(previous_instruction, previous_position);
|
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}
|
|
|
|
let register = self.next_register();
|
|
let mut instruction = match operator.kind() {
|
|
TokenKind::Bang => Instruction::not(register, argument),
|
|
TokenKind::Minus => Instruction::negate(register, argument),
|
|
_ => {
|
|
return Err(ParseError::ExpectedTokenMultiple {
|
|
expected: &[TokenKind::Bang, TokenKind::Minus],
|
|
found: operator.to_owned(),
|
|
position: operator_position,
|
|
})
|
|
}
|
|
};
|
|
|
|
if is_constant {
|
|
instruction.set_b_is_constant();
|
|
}
|
|
|
|
self.emit_instruction(instruction, operator_position);
|
|
|
|
self.current_is_expression = true;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn handle_binary_argument(
|
|
&mut self,
|
|
instruction: &Instruction,
|
|
) -> Result<(bool, bool, bool, u8), ParseError> {
|
|
let mut push_back = false;
|
|
let mut is_constant = false;
|
|
let mut is_mutable_local = false;
|
|
let argument = match instruction.operation() {
|
|
Operation::GetLocal => {
|
|
let local_index = instruction.b();
|
|
let local = self.get_local(local_index)?;
|
|
is_mutable_local = local.is_mutable;
|
|
|
|
local.register_index
|
|
}
|
|
Operation::LoadConstant => {
|
|
is_constant = true;
|
|
|
|
instruction.b()
|
|
}
|
|
Operation::Close => {
|
|
return Err(ParseError::ExpectedExpression {
|
|
found: self.previous_token.to_owned(),
|
|
position: self.previous_position,
|
|
});
|
|
}
|
|
_ => {
|
|
push_back = true;
|
|
|
|
if instruction.yields_value() {
|
|
instruction.a()
|
|
} else {
|
|
self.next_register()
|
|
}
|
|
}
|
|
};
|
|
|
|
Ok((push_back, is_constant, is_mutable_local, argument))
|
|
}
|
|
|
|
fn parse_math_binary(&mut self) -> Result<(), ParseError> {
|
|
let (left_instruction, left_position) =
|
|
self.chunk
|
|
.instructions_mut()
|
|
.pop()
|
|
.ok_or_else(|| ParseError::ExpectedExpression {
|
|
found: self.previous_token.to_owned(),
|
|
position: self.previous_position,
|
|
})?;
|
|
let (push_back_left, left_is_constant, left_is_mutable_local, left) =
|
|
self.handle_binary_argument(&left_instruction)?;
|
|
|
|
if push_back_left {
|
|
self.emit_instruction(left_instruction, left_position);
|
|
}
|
|
|
|
let operator = self.current_token;
|
|
let operator_position = self.current_position;
|
|
let rule = ParseRule::from(&operator);
|
|
|
|
if let Token::PlusEqual | Token::MinusEqual | Token::StarEqual | Token::SlashEqual =
|
|
operator
|
|
{
|
|
if !left_is_mutable_local {
|
|
return Err(ParseError::ExpectedMutableVariable {
|
|
found: self.previous_token.to_owned(),
|
|
position: left_position,
|
|
});
|
|
}
|
|
}
|
|
|
|
self.advance()?;
|
|
self.parse_sub_expression(&rule.precedence)?;
|
|
|
|
let (right_instruction, right_position) = self.pop_last_instruction()?;
|
|
let (push_back_right, right_is_constant, _, right) =
|
|
self.handle_binary_argument(&right_instruction)?;
|
|
|
|
if push_back_right {
|
|
self.emit_instruction(right_instruction, right_position);
|
|
}
|
|
|
|
let register = if left_is_mutable_local {
|
|
left
|
|
} else {
|
|
self.next_register()
|
|
};
|
|
|
|
let mut new_instruction = match operator {
|
|
Token::Plus => Instruction::add(register, left, right),
|
|
Token::PlusEqual => Instruction::add(register, left, right),
|
|
Token::Minus => Instruction::subtract(register, left, right),
|
|
Token::MinusEqual => Instruction::subtract(register, left, right),
|
|
Token::Star => Instruction::multiply(register, left, right),
|
|
Token::StarEqual => Instruction::multiply(register, left, right),
|
|
Token::Slash => Instruction::divide(register, left, right),
|
|
Token::SlashEqual => Instruction::divide(register, left, right),
|
|
Token::Percent => Instruction::modulo(register, left, right),
|
|
Token::PercentEqual => Instruction::modulo(register, left, right),
|
|
_ => {
|
|
return Err(ParseError::ExpectedTokenMultiple {
|
|
expected: &[
|
|
TokenKind::Plus,
|
|
TokenKind::PlusEqual,
|
|
TokenKind::Minus,
|
|
TokenKind::MinusEqual,
|
|
TokenKind::Star,
|
|
TokenKind::StarEqual,
|
|
TokenKind::Slash,
|
|
TokenKind::SlashEqual,
|
|
TokenKind::Percent,
|
|
TokenKind::PercentEqual,
|
|
],
|
|
found: operator.to_owned(),
|
|
position: operator_position,
|
|
})
|
|
}
|
|
};
|
|
|
|
if left_is_constant {
|
|
new_instruction.set_b_is_constant();
|
|
}
|
|
|
|
if right_is_constant {
|
|
new_instruction.set_c_is_constant();
|
|
}
|
|
|
|
self.emit_instruction(new_instruction, operator_position);
|
|
|
|
if let Token::PlusEqual
|
|
| Token::MinusEqual
|
|
| Token::StarEqual
|
|
| Token::SlashEqual
|
|
| Token::PercentEqual = operator
|
|
{
|
|
self.current_is_expression = false;
|
|
} else {
|
|
self.current_is_expression = true;
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_comparison_binary(&mut self) -> Result<(), ParseError> {
|
|
if let Some(Operation::Equal | Operation::Less | Operation::LessEqual) =
|
|
self.get_last_value_operation()
|
|
{
|
|
return Err(ParseError::CannotChainComparison {
|
|
position: self.current_position,
|
|
});
|
|
}
|
|
|
|
let (left_instruction, left_position) =
|
|
self.chunk
|
|
.instructions_mut()
|
|
.pop()
|
|
.ok_or_else(|| ParseError::ExpectedExpression {
|
|
found: self.previous_token.to_owned(),
|
|
position: self.previous_position,
|
|
})?;
|
|
let (push_back_left, left_is_constant, _, left) =
|
|
self.handle_binary_argument(&left_instruction)?;
|
|
|
|
let operator = self.current_token;
|
|
let operator_position = self.current_position;
|
|
let rule = ParseRule::from(&operator);
|
|
|
|
self.advance()?;
|
|
self.parse_sub_expression(&rule.precedence)?;
|
|
|
|
let (right_instruction, right_position) =
|
|
self.chunk
|
|
.instructions_mut()
|
|
.pop()
|
|
.ok_or_else(|| ParseError::ExpectedExpression {
|
|
found: self.previous_token.to_owned(),
|
|
position: self.previous_position,
|
|
})?;
|
|
let (push_back_right, right_is_constant, _, right) =
|
|
self.handle_binary_argument(&right_instruction)?;
|
|
|
|
let mut instruction = match operator {
|
|
Token::DoubleEqual => Instruction::equal(true, left, right),
|
|
Token::BangEqual => Instruction::equal(false, left, right),
|
|
Token::Less => Instruction::less(true, left, right),
|
|
Token::LessEqual => Instruction::less_equal(true, left, right),
|
|
Token::Greater => Instruction::less_equal(false, left, right),
|
|
Token::GreaterEqual => Instruction::less(false, left, right),
|
|
_ => {
|
|
return Err(ParseError::ExpectedTokenMultiple {
|
|
expected: &[
|
|
TokenKind::DoubleEqual,
|
|
TokenKind::BangEqual,
|
|
TokenKind::Less,
|
|
TokenKind::LessEqual,
|
|
TokenKind::Greater,
|
|
TokenKind::GreaterEqual,
|
|
],
|
|
found: operator.to_owned(),
|
|
position: operator_position,
|
|
})
|
|
}
|
|
};
|
|
|
|
if left_is_constant {
|
|
instruction.set_b_is_constant();
|
|
}
|
|
|
|
if right_is_constant {
|
|
instruction.set_c_is_constant();
|
|
}
|
|
|
|
if push_back_left {
|
|
self.emit_instruction(left_instruction, left_position);
|
|
}
|
|
|
|
if push_back_right {
|
|
self.emit_instruction(right_instruction, right_position);
|
|
}
|
|
|
|
let register = self.next_register();
|
|
|
|
self.emit_instruction(instruction, operator_position);
|
|
|
|
self.emit_instruction(Instruction::jump(1, true), operator_position);
|
|
self.emit_instruction(
|
|
Instruction::load_boolean(register, true, true),
|
|
operator_position,
|
|
);
|
|
self.emit_instruction(
|
|
Instruction::load_boolean(register, false, false),
|
|
operator_position,
|
|
);
|
|
|
|
self.current_is_expression = true;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_logical_binary(&mut self) -> Result<(), ParseError> {
|
|
let start_length = self.chunk.len();
|
|
let (left_instruction, left_position) = self.pop_last_instruction()?;
|
|
let operator = self.current_token;
|
|
let operator_position = self.current_position;
|
|
let rule = ParseRule::from(&operator);
|
|
|
|
let test_instruction = match operator {
|
|
Token::DoubleAmpersand => Instruction::test(left_instruction.a(), false),
|
|
Token::DoublePipe => Instruction::test(left_instruction.a(), true),
|
|
_ => {
|
|
return Err(ParseError::ExpectedTokenMultiple {
|
|
expected: &[TokenKind::DoubleAmpersand, TokenKind::DoublePipe],
|
|
found: operator.to_owned(),
|
|
position: operator_position,
|
|
})
|
|
}
|
|
};
|
|
|
|
self.advance()?;
|
|
self.emit_instruction(left_instruction, left_position);
|
|
self.emit_instruction(test_instruction, operator_position);
|
|
|
|
let jump_distance = (self.chunk.len() - start_length) as u8;
|
|
|
|
self.emit_instruction(Instruction::jump(jump_distance, true), operator_position);
|
|
self.parse_sub_expression(&rule.precedence)?;
|
|
|
|
self.current_is_expression = true;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_variable(&mut self, allowed: Allowed) -> Result<(), ParseError> {
|
|
let start_position = self.current_position;
|
|
let identifier = if let Token::Identifier(text) = self.current_token {
|
|
self.advance()?;
|
|
|
|
text
|
|
} else {
|
|
return Err(ParseError::ExpectedToken {
|
|
expected: TokenKind::Identifier,
|
|
found: self.current_token.to_owned(),
|
|
position: start_position,
|
|
});
|
|
};
|
|
let local_index = if let Ok(local_index) = self.get_local_index(identifier) {
|
|
local_index
|
|
} else if let Some(native_function) = NativeFunction::from_str(identifier) {
|
|
return self.parse_native_call(native_function);
|
|
} else if Some(identifier) == self.chunk.name().map(|string| string.as_str()) {
|
|
let register = self.next_register();
|
|
let scope = self.chunk.current_scope();
|
|
|
|
self.emit_instruction(Instruction::load_self(register), start_position);
|
|
self.declare_local(identifier, None, false, scope, register);
|
|
|
|
self.current_is_expression = true;
|
|
|
|
return Ok(());
|
|
} else {
|
|
return Err(ParseError::UndeclaredVariable {
|
|
identifier: identifier.to_string(),
|
|
position: start_position,
|
|
});
|
|
};
|
|
|
|
let (is_mutable, local_scope) = {
|
|
let local = self.get_local(local_index)?;
|
|
|
|
(local.is_mutable, local.scope)
|
|
};
|
|
let current_scope = self.chunk.current_scope();
|
|
|
|
if !current_scope.contains(&local_scope) {
|
|
return Err(ParseError::VariableOutOfScope {
|
|
identifier: self.chunk.get_identifier(local_index).unwrap(),
|
|
position: start_position,
|
|
variable_scope: local_scope,
|
|
access_scope: current_scope,
|
|
});
|
|
}
|
|
|
|
if self.allow(Token::Equal)? {
|
|
if !allowed.assignment {
|
|
return Err(ParseError::InvalidAssignmentTarget {
|
|
found: self.current_token.to_owned(),
|
|
position: self.current_position,
|
|
});
|
|
}
|
|
|
|
if !is_mutable {
|
|
return Err(ParseError::CannotMutateImmutableVariable {
|
|
identifier: self.chunk.get_identifier(local_index).unwrap(),
|
|
position: start_position,
|
|
});
|
|
}
|
|
|
|
self.parse_expression()?;
|
|
|
|
let (mut previous_instruction, previous_position) =
|
|
self.chunk.instructions_mut().pop().ok_or_else(|| {
|
|
ParseError::ExpectedExpression {
|
|
found: self.previous_token.to_owned(),
|
|
position: self.previous_position,
|
|
}
|
|
})?;
|
|
|
|
if previous_instruction.operation().is_math() {
|
|
let register_index = self.get_local(local_index)?.register_index;
|
|
|
|
log::trace!("Condensing SET_LOCAL to binary math expression");
|
|
|
|
previous_instruction.set_a(register_index);
|
|
self.emit_instruction(previous_instruction, self.current_position);
|
|
|
|
return Ok(());
|
|
}
|
|
|
|
let register = self.next_register();
|
|
|
|
self.emit_instruction(previous_instruction, previous_position);
|
|
self.emit_instruction(
|
|
Instruction::set_local(register, local_index),
|
|
start_position,
|
|
);
|
|
self.optimize_statement();
|
|
|
|
self.current_is_expression = false;
|
|
} else {
|
|
let register = self.next_register();
|
|
|
|
self.emit_instruction(
|
|
Instruction::get_local(register, local_index),
|
|
self.previous_position,
|
|
);
|
|
|
|
self.current_is_expression = true;
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_type_from(&mut self, token: Token, position: Span) -> Result<Type, ParseError> {
|
|
match token {
|
|
Token::Bool => Ok(Type::Boolean),
|
|
Token::FloatKeyword => Ok(Type::Float),
|
|
Token::Int => Ok(Type::Integer),
|
|
Token::Str => Ok(Type::String { length: None }),
|
|
_ => Err(ParseError::ExpectedTokenMultiple {
|
|
expected: &[
|
|
TokenKind::Bool,
|
|
TokenKind::FloatKeyword,
|
|
TokenKind::Int,
|
|
TokenKind::Str,
|
|
],
|
|
found: self.current_token.to_owned(),
|
|
position,
|
|
}),
|
|
}
|
|
}
|
|
|
|
fn parse_block(&mut self, allowed: Allowed) -> Result<(), ParseError> {
|
|
self.advance()?;
|
|
self.chunk.begin_scope();
|
|
|
|
while !self.allow(Token::RightCurlyBrace)? && !self.is_eof() {
|
|
self.parse(Precedence::None, allowed)?;
|
|
}
|
|
|
|
self.chunk.end_scope();
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_list(&mut self, _: Allowed) -> Result<(), ParseError> {
|
|
let start = self.current_position.0;
|
|
|
|
self.advance()?;
|
|
|
|
let start_register = self.next_register();
|
|
|
|
while !self.allow(Token::RightSquareBrace)? && !self.is_eof() {
|
|
let expected_register = self.next_register();
|
|
|
|
self.parse_expression()?;
|
|
|
|
let actual_register = self.next_register() - 1;
|
|
|
|
if expected_register < actual_register {
|
|
self.emit_instruction(
|
|
Instruction::close(expected_register, actual_register),
|
|
self.current_position,
|
|
);
|
|
}
|
|
|
|
self.allow(Token::Comma)?;
|
|
}
|
|
|
|
let to_register = self.next_register();
|
|
let end = self.current_position.1;
|
|
|
|
self.emit_instruction(
|
|
Instruction::load_list(to_register, start_register),
|
|
Span(start, end),
|
|
);
|
|
|
|
self.current_is_expression = true;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_if(&mut self, allowed: Allowed) -> Result<(), ParseError> {
|
|
self.advance()?;
|
|
self.parse_expression()?;
|
|
|
|
if matches!(
|
|
self.get_last_instructions(),
|
|
Some([
|
|
Operation::LoadBoolean,
|
|
Operation::LoadBoolean,
|
|
Operation::Jump,
|
|
Operation::Equal | Operation::Less | Operation::LessEqual
|
|
],)
|
|
) {
|
|
self.chunk.instructions_mut().pop();
|
|
self.chunk.instructions_mut().pop();
|
|
}
|
|
|
|
let block_allowed = Allowed {
|
|
assignment: allowed.assignment,
|
|
explicit_return: allowed.explicit_return,
|
|
};
|
|
|
|
if let Token::LeftCurlyBrace = self.current_token {
|
|
let block_start = self.chunk.len();
|
|
|
|
self.parse_block(block_allowed)?;
|
|
|
|
let block_end = self.chunk.len();
|
|
let jump_distance = (block_end - block_start) as u8;
|
|
|
|
if let Some(jump) = self.get_last_jump_mut() {
|
|
jump.set_b(jump_distance);
|
|
}
|
|
} else {
|
|
return Err(ParseError::ExpectedToken {
|
|
expected: TokenKind::LeftCurlyBrace,
|
|
found: self.current_token.to_owned(),
|
|
position: self.current_position,
|
|
});
|
|
}
|
|
|
|
let if_block_is_expression = self
|
|
.chunk
|
|
.instructions()
|
|
.iter()
|
|
.rev()
|
|
.find_map(|(instruction, _)| {
|
|
if !matches!(instruction.operation(), Operation::Jump | Operation::Move) {
|
|
Some(instruction.yields_value())
|
|
} else {
|
|
None
|
|
}
|
|
})
|
|
.unwrap_or(false);
|
|
|
|
if let Token::Else = self.current_token {
|
|
let else_start = self.chunk.len();
|
|
let if_last_register = self.next_register().saturating_sub(1);
|
|
|
|
self.parse_else(allowed, block_allowed)?;
|
|
self.optimize_statement();
|
|
|
|
let else_last_register = self.next_register().saturating_sub(1);
|
|
let else_end = self.chunk.len();
|
|
let jump_distance = (else_end - else_start) as u8;
|
|
|
|
if if_last_register < else_last_register {
|
|
self.emit_instruction(
|
|
Instruction::r#move(else_last_register, if_last_register),
|
|
self.current_position,
|
|
);
|
|
}
|
|
|
|
self.current_is_expression = if_block_is_expression && self.current_is_expression;
|
|
|
|
if jump_distance == 1 {
|
|
if let Some(skippable) = self.get_last_jumpable_mut() {
|
|
skippable.set_c_to_boolean(true);
|
|
} else {
|
|
self.chunk.instructions_mut().insert(
|
|
else_start,
|
|
(
|
|
Instruction::jump(jump_distance, true),
|
|
self.current_position,
|
|
),
|
|
);
|
|
}
|
|
} else {
|
|
self.chunk.instructions_mut().insert(
|
|
else_start,
|
|
(
|
|
Instruction::jump(jump_distance, true),
|
|
self.current_position,
|
|
),
|
|
);
|
|
}
|
|
} else {
|
|
self.current_is_expression = false;
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_else(&mut self, allowed: Allowed, block_allowed: Allowed) -> Result<(), ParseError> {
|
|
self.advance()?;
|
|
|
|
let if_block_end = self.chunk.len();
|
|
|
|
if let Token::If = self.current_token {
|
|
self.parse_if(allowed)?;
|
|
} else if let Token::LeftCurlyBrace = self.current_token {
|
|
self.parse_block(block_allowed)?;
|
|
|
|
let else_end = self.chunk.len();
|
|
|
|
if else_end - if_block_end > 1 {
|
|
let jump_distance = (else_end - if_block_end) as u8;
|
|
|
|
self.chunk.instructions_mut().insert(
|
|
if_block_end,
|
|
(
|
|
Instruction::jump(jump_distance, true),
|
|
self.current_position,
|
|
),
|
|
);
|
|
}
|
|
} else {
|
|
return Err(ParseError::ExpectedTokenMultiple {
|
|
expected: &[TokenKind::If, TokenKind::LeftCurlyBrace],
|
|
found: self.current_token.to_owned(),
|
|
position: self.current_position,
|
|
});
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_while(&mut self, allowed: Allowed) -> Result<(), ParseError> {
|
|
self.advance()?;
|
|
|
|
let expression_start = self.chunk.len() as u8;
|
|
|
|
self.parse_expression()?;
|
|
|
|
if matches!(
|
|
self.get_last_instructions(),
|
|
Some([
|
|
Operation::LoadBoolean,
|
|
Operation::LoadBoolean,
|
|
Operation::Jump,
|
|
Operation::Equal | Operation::Less | Operation::LessEqual
|
|
],)
|
|
) {
|
|
self.chunk.instructions_mut().pop();
|
|
self.chunk.instructions_mut().pop();
|
|
self.chunk.instructions_mut().pop();
|
|
}
|
|
|
|
let block_start = self.chunk.len();
|
|
|
|
self.parse_block(Allowed {
|
|
assignment: true,
|
|
explicit_return: allowed.explicit_return,
|
|
})?;
|
|
|
|
let block_end = self.chunk.len() as u8;
|
|
|
|
self.chunk.instructions_mut().insert(
|
|
block_start,
|
|
(
|
|
Instruction::jump(block_end - block_start as u8 + 1, true),
|
|
self.current_position,
|
|
),
|
|
);
|
|
|
|
let jump_back_distance = block_end - expression_start + 1;
|
|
let jump_back = Instruction::jump(jump_back_distance, false);
|
|
|
|
self.emit_instruction(jump_back, self.current_position);
|
|
self.optimize_statement();
|
|
|
|
self.current_is_expression = false;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_native_call(&mut self, function: NativeFunction) -> Result<(), ParseError> {
|
|
let start = self.previous_position.0;
|
|
let start_register = self.next_register();
|
|
|
|
self.expect(Token::LeftParenthesis)?;
|
|
|
|
while !self.allow(Token::RightParenthesis)? {
|
|
let expected_register = self.next_register();
|
|
|
|
self.parse_expression()?;
|
|
|
|
let actual_register = self.next_register() - 1;
|
|
|
|
if expected_register < actual_register {
|
|
self.emit_instruction(
|
|
Instruction::close(expected_register, actual_register),
|
|
self.current_position,
|
|
);
|
|
}
|
|
|
|
self.allow(Token::Comma)?;
|
|
}
|
|
|
|
let end = self.previous_position.1;
|
|
let to_register = self.next_register();
|
|
let argument_count = to_register - start_register;
|
|
self.current_is_expression = function.r#type().return_type.is_some();
|
|
|
|
self.emit_instruction(
|
|
Instruction::call_native(to_register, function, argument_count),
|
|
Span(start, end),
|
|
);
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_top_level(&mut self) -> Result<(), ParseError> {
|
|
loop {
|
|
self.parse(
|
|
Precedence::None,
|
|
Allowed {
|
|
assignment: true,
|
|
explicit_return: false,
|
|
},
|
|
)?;
|
|
|
|
if self.is_eof() || self.allow(Token::RightCurlyBrace)? {
|
|
self.parse_implicit_return()?;
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_expression(&mut self) -> Result<(), ParseError> {
|
|
self.parse(
|
|
Precedence::None,
|
|
Allowed {
|
|
assignment: false,
|
|
explicit_return: false,
|
|
},
|
|
)?;
|
|
|
|
if !self.current_is_expression || self.chunk.is_empty() {
|
|
return Err(ParseError::ExpectedExpression {
|
|
found: self.previous_token.to_owned(),
|
|
position: self.current_position,
|
|
});
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_sub_expression(&mut self, precedence: &Precedence) -> Result<(), ParseError> {
|
|
self.parse(
|
|
precedence.increment(),
|
|
Allowed {
|
|
assignment: false,
|
|
explicit_return: false,
|
|
},
|
|
)
|
|
}
|
|
|
|
fn parse_return(&mut self, allowed: Allowed) -> Result<(), ParseError> {
|
|
if !allowed.explicit_return {
|
|
return Err(ParseError::UnexpectedReturn {
|
|
position: self.current_position,
|
|
});
|
|
}
|
|
|
|
let start = self.current_position.0;
|
|
|
|
self.advance()?;
|
|
|
|
let has_return_value = if matches!(
|
|
self.current_token,
|
|
Token::Semicolon | Token::RightCurlyBrace
|
|
) {
|
|
false
|
|
} else {
|
|
self.parse_expression()?;
|
|
|
|
true
|
|
};
|
|
let end = self.current_position.1;
|
|
|
|
self.emit_instruction(Instruction::r#return(has_return_value), Span(start, end));
|
|
self.optimize_statement();
|
|
|
|
self.current_is_expression = false;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_implicit_return(&mut self) -> Result<(), ParseError> {
|
|
let has_semicolon = self.allow(Token::Semicolon)?;
|
|
|
|
if has_semicolon {
|
|
self.emit_instruction(Instruction::r#return(false), self.current_position);
|
|
} else {
|
|
self.emit_instruction(
|
|
Instruction::r#return(self.current_is_expression),
|
|
self.current_position,
|
|
);
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_let_statement(&mut self, allowed: Allowed) -> Result<(), ParseError> {
|
|
if !allowed.assignment {
|
|
return Err(ParseError::ExpectedExpression {
|
|
found: self.current_token.to_owned(),
|
|
position: self.current_position,
|
|
});
|
|
}
|
|
|
|
self.advance()?;
|
|
|
|
let scope = self.chunk.current_scope();
|
|
let is_mutable = self.allow(Token::Mut)?;
|
|
let position = self.current_position;
|
|
let identifier = if let Token::Identifier(text) = self.current_token {
|
|
self.advance()?;
|
|
|
|
text
|
|
} else {
|
|
return Err(ParseError::ExpectedToken {
|
|
expected: TokenKind::Identifier,
|
|
found: self.current_token.to_owned(),
|
|
position,
|
|
});
|
|
};
|
|
let r#type = if self.allow(Token::Colon)? {
|
|
let r#type = self.parse_type_from(self.current_token, self.current_position)?;
|
|
|
|
self.advance()?;
|
|
|
|
Some(r#type)
|
|
} else {
|
|
None
|
|
};
|
|
let register = self.next_register();
|
|
|
|
self.expect(Token::Equal)?;
|
|
self.parse_expression()?;
|
|
|
|
let (local_index, _) = self.declare_local(identifier, r#type, is_mutable, scope, register);
|
|
let register = self.next_register().saturating_sub(1);
|
|
|
|
self.emit_instruction(
|
|
Instruction::define_local(register, local_index, is_mutable),
|
|
position,
|
|
);
|
|
self.optimize_statement();
|
|
|
|
self.current_is_expression = false;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_function(&mut self, _: Allowed) -> Result<(), ParseError> {
|
|
let function_start = self.current_position.0;
|
|
let mut function_parser = Parser::new(self.lexer)?;
|
|
let identifier = if let Token::Identifier(text) = function_parser.current_token {
|
|
let position = function_parser.current_position;
|
|
|
|
function_parser.advance()?;
|
|
function_parser.chunk.set_name(text.to_string());
|
|
|
|
Some((text, position))
|
|
} else {
|
|
None
|
|
};
|
|
|
|
function_parser.expect(Token::LeftParenthesis)?;
|
|
|
|
let mut value_parameters: Option<Vec<(u8, Type)>> = None;
|
|
|
|
while function_parser.current_token != Token::RightParenthesis {
|
|
let is_mutable = function_parser.allow(Token::Mut)?;
|
|
let parameter = if let Token::Identifier(text) = function_parser.current_token {
|
|
function_parser.advance()?;
|
|
|
|
text
|
|
} else {
|
|
return Err(ParseError::ExpectedToken {
|
|
expected: TokenKind::Identifier,
|
|
found: function_parser.current_token.to_owned(),
|
|
position: function_parser.current_position,
|
|
});
|
|
};
|
|
|
|
function_parser.expect(Token::Colon)?;
|
|
|
|
let r#type = function_parser.parse_type_from(
|
|
function_parser.current_token,
|
|
function_parser.current_position,
|
|
)?;
|
|
|
|
function_parser.advance()?;
|
|
|
|
let register = value_parameters
|
|
.as_ref()
|
|
.map(|values| values.len() as u8)
|
|
.unwrap_or(0);
|
|
let scope = function_parser.chunk.current_scope();
|
|
let (_, identifier_index) = function_parser.declare_local(
|
|
parameter,
|
|
Some(r#type.clone()),
|
|
is_mutable,
|
|
scope,
|
|
register,
|
|
);
|
|
|
|
if let Some(value_parameters) = value_parameters.as_mut() {
|
|
value_parameters.push((identifier_index, r#type));
|
|
} else {
|
|
value_parameters = Some(vec![(identifier_index, r#type)]);
|
|
};
|
|
|
|
function_parser.minimum_register += 1;
|
|
|
|
function_parser.allow(Token::Comma)?;
|
|
}
|
|
|
|
function_parser.advance()?;
|
|
|
|
let return_type = if function_parser.allow(Token::ArrowThin)? {
|
|
let r#type = function_parser.parse_type_from(
|
|
function_parser.current_token,
|
|
function_parser.current_position,
|
|
)?;
|
|
|
|
function_parser.advance()?;
|
|
|
|
Some(Box::new(r#type))
|
|
} else {
|
|
None
|
|
};
|
|
|
|
function_parser.expect(Token::LeftCurlyBrace)?;
|
|
function_parser.parse_top_level()?;
|
|
|
|
self.previous_token = function_parser.previous_token;
|
|
self.previous_position = function_parser.previous_position;
|
|
self.current_token = function_parser.current_token;
|
|
self.current_position = function_parser.current_position;
|
|
|
|
let function_type = FunctionType {
|
|
type_parameters: None,
|
|
value_parameters,
|
|
return_type,
|
|
};
|
|
let function = Value::function(function_parser.finish(), function_type.clone());
|
|
let function_end = self.current_position.1;
|
|
|
|
self.lexer.skip_to(function_end);
|
|
|
|
if let Some((identifier, identifier_position)) = identifier {
|
|
let register = self.next_register();
|
|
let scope = self.chunk.current_scope();
|
|
let (local_index, _) = self.declare_local(
|
|
identifier,
|
|
Some(Type::Function(function_type)),
|
|
false,
|
|
scope,
|
|
register,
|
|
);
|
|
|
|
self.emit_constant(function, Span(function_start, function_end))?;
|
|
self.emit_instruction(
|
|
Instruction::define_local(register, local_index, false),
|
|
identifier_position,
|
|
);
|
|
self.optimize_statement();
|
|
|
|
self.current_is_expression = false;
|
|
} else {
|
|
self.emit_constant(function, Span(function_start, function_end))?;
|
|
self.optimize_statement();
|
|
|
|
self.current_is_expression = true;
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_call(&mut self) -> Result<(), ParseError> {
|
|
let (last_instruction, _) =
|
|
self.chunk
|
|
.instructions()
|
|
.last()
|
|
.ok_or_else(|| ParseError::ExpectedExpression {
|
|
found: self.previous_token.to_owned(),
|
|
position: self.previous_position,
|
|
})?;
|
|
|
|
if !last_instruction.yields_value() {
|
|
return Err(ParseError::ExpectedExpression {
|
|
found: self.previous_token.to_owned(),
|
|
position: self.previous_position,
|
|
});
|
|
}
|
|
|
|
let function_register = last_instruction.a();
|
|
let start = self.current_position.0;
|
|
|
|
self.advance()?;
|
|
|
|
while !self.allow(Token::RightParenthesis)? {
|
|
let expected_register = self.next_register();
|
|
|
|
self.parse_expression()?;
|
|
|
|
let actual_register = self.next_register() - 1;
|
|
|
|
if expected_register < actual_register {
|
|
self.emit_instruction(
|
|
Instruction::close(expected_register, actual_register),
|
|
self.current_position,
|
|
);
|
|
}
|
|
|
|
self.allow(Token::Comma)?;
|
|
}
|
|
|
|
let end = self.current_position.1;
|
|
let to_register = self.next_register();
|
|
let argument_count = to_register - function_register - 1;
|
|
|
|
self.emit_instruction(
|
|
Instruction::call(to_register, function_register, argument_count),
|
|
Span(start, end),
|
|
);
|
|
|
|
self.current_is_expression = true;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn parse_semicolon(&mut self, _: Allowed) -> Result<(), ParseError> {
|
|
self.advance()?;
|
|
|
|
self.current_is_expression = false;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn expect_expression(&mut self, _: Allowed) -> Result<(), ParseError> {
|
|
Err(ParseError::ExpectedExpression {
|
|
found: self.current_token.to_owned(),
|
|
position: self.current_position,
|
|
})
|
|
}
|
|
|
|
fn parse(&mut self, precedence: Precedence, allowed: Allowed) -> Result<(), ParseError> {
|
|
if let Some(prefix_parser) = ParseRule::from(&self.current_token).prefix {
|
|
log::debug!(
|
|
"{} is prefix with precedence {precedence}",
|
|
self.current_token.to_string().bold(),
|
|
);
|
|
|
|
prefix_parser(self, allowed)?;
|
|
}
|
|
|
|
let mut infix_rule = ParseRule::from(&self.current_token);
|
|
|
|
while precedence <= infix_rule.precedence {
|
|
if let Some(infix_parser) = infix_rule.infix {
|
|
log::debug!(
|
|
"{} is infix with precedence {precedence}",
|
|
self.current_token.to_string().bold(),
|
|
);
|
|
|
|
if !allowed.assignment && self.current_token == Token::Equal {
|
|
return Err(ParseError::InvalidAssignmentTarget {
|
|
found: self.current_token.to_owned(),
|
|
position: self.current_position,
|
|
});
|
|
}
|
|
|
|
infix_parser(self)?;
|
|
} else {
|
|
break;
|
|
}
|
|
|
|
infix_rule = ParseRule::from(&self.current_token);
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
|
|
pub enum Precedence {
|
|
None,
|
|
Assignment,
|
|
Conditional,
|
|
LogicalOr,
|
|
LogicalAnd,
|
|
Equality,
|
|
Comparison,
|
|
Term,
|
|
Factor,
|
|
Unary,
|
|
Call,
|
|
Primary,
|
|
}
|
|
|
|
impl Precedence {
|
|
fn increment(&self) -> Self {
|
|
match self {
|
|
Precedence::None => Precedence::Assignment,
|
|
Precedence::Assignment => Precedence::Conditional,
|
|
Precedence::Conditional => Precedence::LogicalOr,
|
|
Precedence::LogicalOr => Precedence::LogicalAnd,
|
|
Precedence::LogicalAnd => Precedence::Equality,
|
|
Precedence::Equality => Precedence::Comparison,
|
|
Precedence::Comparison => Precedence::Term,
|
|
Precedence::Term => Precedence::Factor,
|
|
Precedence::Factor => Precedence::Unary,
|
|
Precedence::Unary => Precedence::Call,
|
|
Precedence::Call => Precedence::Primary,
|
|
Precedence::Primary => Precedence::Primary,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl Display for Precedence {
|
|
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
|
|
write!(f, "{:?}", self)
|
|
}
|
|
}
|
|
|
|
#[derive(Debug, Clone, Copy, Eq, PartialEq, PartialOrd, Ord, Serialize, Deserialize)]
|
|
pub enum Context {
|
|
None,
|
|
Assignment,
|
|
}
|
|
|
|
#[derive(Debug, Clone, Copy)]
|
|
struct Allowed {
|
|
pub assignment: bool,
|
|
pub explicit_return: bool,
|
|
}
|
|
|
|
type PrefixFunction<'a> = fn(&mut Parser<'a>, Allowed) -> Result<(), ParseError>;
|
|
type InfixFunction<'a> = fn(&mut Parser<'a>) -> Result<(), ParseError>;
|
|
|
|
#[derive(Debug, Clone, Copy)]
|
|
struct ParseRule<'a> {
|
|
pub prefix: Option<PrefixFunction<'a>>,
|
|
pub infix: Option<InfixFunction<'a>>,
|
|
pub precedence: Precedence,
|
|
}
|
|
|
|
impl From<&Token<'_>> for ParseRule<'_> {
|
|
fn from(token: &Token) -> Self {
|
|
match token {
|
|
Token::ArrowThin => ParseRule {
|
|
prefix: Some(Parser::expect_expression),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Async => todo!(),
|
|
Token::Bang => ParseRule {
|
|
prefix: Some(Parser::parse_unary),
|
|
infix: None,
|
|
precedence: Precedence::Unary,
|
|
},
|
|
Token::BangEqual => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_comparison_binary),
|
|
precedence: Precedence::Equality,
|
|
},
|
|
Token::Bool => ParseRule {
|
|
prefix: Some(Parser::expect_expression),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Boolean(_) => ParseRule {
|
|
prefix: Some(Parser::parse_boolean),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Break => todo!(),
|
|
Token::Byte(_) => ParseRule {
|
|
prefix: Some(Parser::parse_byte),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Character(_) => ParseRule {
|
|
prefix: Some(Parser::parse_character),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Colon => ParseRule {
|
|
prefix: Some(Parser::expect_expression),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Comma => ParseRule {
|
|
prefix: None,
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Dot => ParseRule {
|
|
prefix: Some(Parser::expect_expression),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::DoubleAmpersand => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_logical_binary),
|
|
precedence: Precedence::LogicalAnd,
|
|
},
|
|
Token::DoubleEqual => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_comparison_binary),
|
|
precedence: Precedence::Equality,
|
|
},
|
|
Token::DoublePipe => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_logical_binary),
|
|
precedence: Precedence::LogicalOr,
|
|
},
|
|
Token::DoubleDot => ParseRule {
|
|
prefix: Some(Parser::expect_expression),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Eof => ParseRule {
|
|
prefix: None,
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Equal => ParseRule {
|
|
prefix: None,
|
|
infix: None,
|
|
precedence: Precedence::Assignment,
|
|
},
|
|
Token::Else => ParseRule {
|
|
prefix: None,
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Float(_) => ParseRule {
|
|
prefix: Some(Parser::parse_float),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::FloatKeyword => ParseRule {
|
|
prefix: Some(Parser::expect_expression),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Fn => ParseRule {
|
|
prefix: Some(Parser::parse_function),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Greater => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_comparison_binary),
|
|
precedence: Precedence::Comparison,
|
|
},
|
|
Token::GreaterEqual => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_comparison_binary),
|
|
precedence: Precedence::Comparison,
|
|
},
|
|
Token::Identifier(_) => ParseRule {
|
|
prefix: Some(Parser::parse_variable),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::If => ParseRule {
|
|
prefix: Some(Parser::parse_if),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Int => ParseRule {
|
|
prefix: Some(Parser::expect_expression),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Integer(_) => ParseRule {
|
|
prefix: Some(Parser::parse_integer),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::LeftCurlyBrace => ParseRule {
|
|
prefix: Some(Parser::parse_block),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::LeftParenthesis => ParseRule {
|
|
prefix: Some(Parser::parse_grouped),
|
|
infix: Some(Parser::parse_call),
|
|
precedence: Precedence::Call,
|
|
},
|
|
Token::LeftSquareBrace => ParseRule {
|
|
prefix: Some(Parser::parse_list),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Less => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_comparison_binary),
|
|
precedence: Precedence::Comparison,
|
|
},
|
|
Token::LessEqual => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_comparison_binary),
|
|
precedence: Precedence::Comparison,
|
|
},
|
|
Token::Let => ParseRule {
|
|
prefix: Some(Parser::parse_let_statement),
|
|
infix: None,
|
|
precedence: Precedence::Assignment,
|
|
},
|
|
Token::Loop => todo!(),
|
|
Token::Map => todo!(),
|
|
Token::Minus => ParseRule {
|
|
prefix: Some(Parser::parse_unary),
|
|
infix: Some(Parser::parse_math_binary),
|
|
precedence: Precedence::Term,
|
|
},
|
|
Token::MinusEqual => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_math_binary),
|
|
precedence: Precedence::Assignment,
|
|
},
|
|
Token::Mut => ParseRule {
|
|
prefix: None,
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Percent => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_math_binary),
|
|
precedence: Precedence::Factor,
|
|
},
|
|
Token::PercentEqual => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_math_binary),
|
|
precedence: Precedence::Assignment,
|
|
},
|
|
Token::Plus => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_math_binary),
|
|
precedence: Precedence::Term,
|
|
},
|
|
Token::PlusEqual => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_math_binary),
|
|
precedence: Precedence::Assignment,
|
|
},
|
|
Token::Return => ParseRule {
|
|
prefix: Some(Parser::parse_return),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::RightCurlyBrace => ParseRule {
|
|
prefix: None,
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::RightParenthesis => ParseRule {
|
|
prefix: None,
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::RightSquareBrace => ParseRule {
|
|
prefix: None,
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Semicolon => ParseRule {
|
|
prefix: Some(Parser::parse_semicolon),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Slash => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_math_binary),
|
|
precedence: Precedence::Factor,
|
|
},
|
|
Token::SlashEqual => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_math_binary),
|
|
precedence: Precedence::Assignment,
|
|
},
|
|
Token::Star => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_math_binary),
|
|
precedence: Precedence::Factor,
|
|
},
|
|
Token::StarEqual => ParseRule {
|
|
prefix: None,
|
|
infix: Some(Parser::parse_math_binary),
|
|
precedence: Precedence::Assignment,
|
|
},
|
|
Token::Str => ParseRule {
|
|
prefix: Some(Parser::expect_expression),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::String(_) => ParseRule {
|
|
prefix: Some(Parser::parse_string),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
Token::Struct => todo!(),
|
|
Token::While => ParseRule {
|
|
prefix: Some(Parser::parse_while),
|
|
infix: None,
|
|
precedence: Precedence::None,
|
|
},
|
|
}
|
|
}
|
|
}
|
|
|
|
#[derive(Debug, PartialEq)]
|
|
pub enum ParseError {
|
|
// Token errors
|
|
ExpectedToken {
|
|
expected: TokenKind,
|
|
found: TokenOwned,
|
|
position: Span,
|
|
},
|
|
ExpectedTokenMultiple {
|
|
expected: &'static [TokenKind],
|
|
found: TokenOwned,
|
|
position: Span,
|
|
},
|
|
|
|
// Expression errors
|
|
CannotChainComparison {
|
|
position: Span,
|
|
},
|
|
ExpectedExpression {
|
|
found: TokenOwned,
|
|
position: Span,
|
|
},
|
|
|
|
// Variable errors
|
|
CannotMutateImmutableVariable {
|
|
identifier: String,
|
|
position: Span,
|
|
},
|
|
ExpectedMutableVariable {
|
|
found: TokenOwned,
|
|
position: Span,
|
|
},
|
|
UndeclaredVariable {
|
|
identifier: String,
|
|
position: Span,
|
|
},
|
|
VariableOutOfScope {
|
|
identifier: String,
|
|
variable_scope: Scope,
|
|
access_scope: Scope,
|
|
position: Span,
|
|
},
|
|
|
|
// Statement errors
|
|
InvalidAssignmentTarget {
|
|
found: TokenOwned,
|
|
position: Span,
|
|
},
|
|
UnexpectedReturn {
|
|
position: Span,
|
|
},
|
|
|
|
// Chunk errors
|
|
LocalIndexOutOfBounds {
|
|
index: usize,
|
|
position: Span,
|
|
},
|
|
RegisterOverflow {
|
|
position: Span,
|
|
},
|
|
RegisterUnderflow {
|
|
position: Span,
|
|
},
|
|
|
|
// Wrappers around foreign errors
|
|
Lex(LexError),
|
|
ParseFloatError {
|
|
error: ParseFloatError,
|
|
position: Span,
|
|
},
|
|
ParseIntError {
|
|
error: ParseIntError,
|
|
position: Span,
|
|
},
|
|
}
|
|
|
|
impl AnnotatedError for ParseError {
|
|
fn title() -> &'static str {
|
|
"Parse Error"
|
|
}
|
|
|
|
fn description(&self) -> &'static str {
|
|
match self {
|
|
Self::CannotChainComparison { .. } => "Cannot chain comparison",
|
|
Self::CannotMutateImmutableVariable { .. } => "Cannot mutate immutable variable",
|
|
Self::ExpectedExpression { .. } => "Expected an expression",
|
|
Self::ExpectedMutableVariable { .. } => "Expected a mutable variable",
|
|
Self::ExpectedToken { .. } => "Expected a specific token",
|
|
Self::ExpectedTokenMultiple { .. } => "Expected one of multiple tokens",
|
|
Self::InvalidAssignmentTarget { .. } => "Invalid assignment target",
|
|
Self::Lex(error) => error.description(),
|
|
Self::LocalIndexOutOfBounds { .. } => "Local index out of bounds",
|
|
Self::ParseFloatError { .. } => "Failed to parse float",
|
|
Self::ParseIntError { .. } => "Failed to parse integer",
|
|
Self::RegisterOverflow { .. } => "Register overflow",
|
|
Self::RegisterUnderflow { .. } => "Register underflow",
|
|
Self::UndeclaredVariable { .. } => "Undeclared variable",
|
|
Self::UnexpectedReturn { .. } => "Unexpected return",
|
|
Self::VariableOutOfScope { .. } => "Variable out of scope",
|
|
}
|
|
}
|
|
|
|
fn details(&self) -> Option<String> {
|
|
match self {
|
|
Self::CannotChainComparison { .. } => {
|
|
Some("Cannot chain comparison operations".to_string())
|
|
}
|
|
Self::CannotMutateImmutableVariable { identifier, .. } => {
|
|
Some(format!("Cannot mutate immutable variable {identifier}"))
|
|
}
|
|
Self::ExpectedExpression { found, .. } => Some(format!("Found {found}")),
|
|
Self::ExpectedToken {
|
|
expected, found, ..
|
|
} => Some(format!("Expected {expected} but found {found}")),
|
|
Self::ExpectedTokenMultiple {
|
|
expected, found, ..
|
|
} => {
|
|
let mut details = String::from("Expected");
|
|
|
|
for (index, token) in expected.iter().enumerate() {
|
|
details.push_str(&format!(" {token}"));
|
|
|
|
if index < expected.len() - 2 {
|
|
details.push_str(", ");
|
|
}
|
|
|
|
if index == expected.len() - 2 {
|
|
details.push_str(" or");
|
|
}
|
|
}
|
|
|
|
details.push_str(&format!(" but found {found}"));
|
|
|
|
Some(details)
|
|
}
|
|
Self::ExpectedMutableVariable { found, .. } => {
|
|
Some(format!("Expected mutable variable, found {found}"))
|
|
}
|
|
Self::InvalidAssignmentTarget { found, .. } => {
|
|
Some(format!("Invalid assignment target, found {found}"))
|
|
}
|
|
Self::Lex(error) => error.details(),
|
|
Self::LocalIndexOutOfBounds { index, .. } => {
|
|
Some(format!("Local index {index} out of bounds"))
|
|
}
|
|
Self::ParseFloatError { error, .. } => Some(error.to_string()),
|
|
Self::ParseIntError { error, .. } => Some(error.to_string()),
|
|
Self::RegisterOverflow { .. } => None,
|
|
Self::RegisterUnderflow { .. } => None,
|
|
Self::UndeclaredVariable { identifier, .. } => {
|
|
Some(format!("Undeclared variable {identifier}"))
|
|
}
|
|
Self::UnexpectedReturn { .. } => None,
|
|
Self::VariableOutOfScope { identifier, .. } => {
|
|
Some(format!("Variable {identifier} is out of scope"))
|
|
}
|
|
}
|
|
}
|
|
|
|
fn position(&self) -> Span {
|
|
match self {
|
|
Self::CannotChainComparison { position } => *position,
|
|
Self::CannotMutateImmutableVariable { position, .. } => *position,
|
|
Self::ExpectedExpression { position, .. } => *position,
|
|
Self::ExpectedMutableVariable { position, .. } => *position,
|
|
Self::ExpectedToken { position, .. } => *position,
|
|
Self::ExpectedTokenMultiple { position, .. } => *position,
|
|
Self::InvalidAssignmentTarget { position, .. } => *position,
|
|
Self::Lex(error) => error.position(),
|
|
Self::LocalIndexOutOfBounds { position, .. } => *position,
|
|
Self::ParseFloatError { position, .. } => *position,
|
|
Self::ParseIntError { position, .. } => *position,
|
|
Self::RegisterOverflow { position } => *position,
|
|
Self::RegisterUnderflow { position } => *position,
|
|
Self::UndeclaredVariable { position, .. } => *position,
|
|
Self::UnexpectedReturn { position } => *position,
|
|
Self::VariableOutOfScope { position, .. } => *position,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl From<LexError> for ParseError {
|
|
fn from(error: LexError) -> Self {
|
|
Self::Lex(error)
|
|
}
|
|
}
|