1466 lines
41 KiB
Rust
1466 lines
41 KiB
Rust
//! Lexing tools.
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//!
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//! This module provides two lexing options:
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//! - [`lex`], which lexes the entire input and returns a vector of tokens and their positions
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//! - [`Lexer`], which lexes the input a token at a time
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use crate::{dust_error::AnnotatedError, Span, Token};
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/// Lexes the input and return a vector of tokens and their positions.
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///
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/// # Examples
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/// ```
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/// # use dust_lang::*;
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/// let input = "x = 1 + 2";
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/// let tokens = lex(input).unwrap();
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///
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/// assert_eq!(
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/// tokens,
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/// [
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/// (Token::Identifier("x"), Span(0, 1)),
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/// (Token::Equal, Span(2, 3)),
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/// (Token::Integer("1"), Span(4, 5)),
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/// (Token::Plus, Span(6, 7)),
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/// (Token::Integer("2"), Span(8, 9)),
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/// (Token::Eof, Span(9, 9)),
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/// ]
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/// );
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/// ```
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pub fn lex<'chars, 'src: 'chars>(
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source: &'src str,
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) -> Result<Vec<(Token<'chars>, Span)>, LexError> {
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let mut lexer = Lexer::new(source);
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let mut tokens = Vec::new();
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loop {
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let (token, span) = lexer.next_token()?;
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let is_eof = matches!(token, Token::Eof);
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tokens.push((token, span));
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if is_eof {
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break;
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}
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}
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Ok(tokens)
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}
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/// Low-level tool for lexing a single token at a time.
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///
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/// # Examples
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/// ```
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/// # use dust_lang::*;
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/// let input = "x = 1 + 2";
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/// let mut lexer = Lexer::new(input);
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/// let mut tokens = Vec::new();
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///
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/// loop {
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/// let (token, span) = lexer.next_token().unwrap();
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/// let is_eof = matches!(token, Token::Eof);
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///
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/// tokens.push((token, span));
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///
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/// if is_eof {
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/// break;
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/// }
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/// }
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///
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/// assert_eq!(
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/// tokens,
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/// [
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/// (Token::Identifier("x"), Span(0, 1)),
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/// (Token::Equal, Span(2, 3)),
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/// (Token::Integer("1"), Span(4, 5)),
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/// (Token::Plus, Span(6, 7)),
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/// (Token::Integer("2"), Span(8, 9)),
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/// (Token::Eof, Span(9, 9)),
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/// ]
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/// )
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/// ```
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#[derive(Debug, Clone)]
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pub struct Lexer<'src> {
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source: &'src str,
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position: usize,
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}
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impl<'src> Lexer<'src> {
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/// Create a new lexer for the given input.
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pub fn new(source: &'src str) -> Self {
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Lexer {
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source,
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position: 0,
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}
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}
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/// Produce the next token.
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pub fn next_token(&mut self) -> Result<(Token<'src>, Span), LexError> {
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self.skip_whitespace();
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let (token, span) = if let Some(c) = self.peek_char() {
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match c {
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'0'..='9' => self.lex_numeric()?,
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'-' => {
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let second_char = self.peek_second_char();
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if let Some('=') = second_char {
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self.position += 2;
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(Token::MinusEqual, Span(self.position - 2, self.position))
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} else if let Some('0'..='9') = second_char {
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self.lex_numeric()?
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} else if "-Infinity" == self.peek_chars(9) {
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self.position += 9;
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(
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Token::Float("-Infinity"),
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Span(self.position - 9, self.position),
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)
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} else {
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self.position += 1;
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(Token::Minus, Span(self.position - 1, self.position))
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}
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}
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'a'..='z' | 'A'..='Z' => self.lex_alphanumeric()?,
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'"' => self.lex_string()?,
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'\'' => {
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self.position += 1;
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if let Some(c) = self.peek_char() {
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self.position += 1;
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if let Some('\'') = self.peek_char() {
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self.position += 1;
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(Token::Character(c), Span(self.position - 3, self.position))
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} else {
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return Err(LexError::ExpectedCharacter {
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expected: '\'',
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actual: c,
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position: self.position,
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});
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}
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} else {
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return Err(LexError::UnexpectedEndOfFile {
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position: self.position,
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});
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}
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}
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'+' => {
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if let Some('=') = self.peek_second_char() {
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self.position += 2;
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(Token::PlusEqual, Span(self.position - 2, self.position))
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} else {
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self.position += 1;
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(Token::Plus, Span(self.position - 1, self.position))
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}
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}
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'*' => {
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if let Some('=') = self.peek_second_char() {
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self.position += 2;
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(Token::StarEqual, Span(self.position - 2, self.position))
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} else {
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self.position += 1;
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(Token::Star, Span(self.position - 1, self.position))
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}
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}
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'(' => {
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self.position += 1;
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(
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Token::LeftParenthesis,
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Span(self.position - 1, self.position),
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)
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}
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')' => {
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self.position += 1;
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(
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Token::RightParenthesis,
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Span(self.position - 1, self.position),
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)
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}
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'=' => {
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if let Some('=') = self.peek_second_char() {
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self.position += 2;
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(Token::DoubleEqual, Span(self.position - 2, self.position))
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} else {
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self.position += 1;
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(Token::Equal, Span(self.position - 1, self.position))
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}
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}
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'[' => {
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self.position += 1;
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(
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Token::LeftSquareBrace,
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Span(self.position - 1, self.position),
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)
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}
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']' => {
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self.position += 1;
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(
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Token::RightSquareBrace,
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Span(self.position - 1, self.position),
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)
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}
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',' => {
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self.position += 1;
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(Token::Comma, Span(self.position - 1, self.position))
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}
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'.' => {
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if let Some('.') = self.peek_second_char() {
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self.position += 2;
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(Token::DoubleDot, Span(self.position - 2, self.position))
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} else {
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self.position += 1;
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(Token::Dot, Span(self.position - 1, self.position))
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}
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}
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'>' => {
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if let Some('=') = self.peek_second_char() {
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self.position += 2;
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(Token::GreaterEqual, Span(self.position - 2, self.position))
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} else {
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self.position += 1;
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(Token::Greater, Span(self.position - 1, self.position))
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}
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}
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'<' => {
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if let Some('=') = self.peek_second_char() {
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self.position += 2;
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(Token::LessEqual, Span(self.position - 2, self.position))
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} else {
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self.position += 1;
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(Token::Less, Span(self.position - 1, self.position))
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}
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}
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'{' => {
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self.position += 1;
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(
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Token::LeftCurlyBrace,
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Span(self.position - 1, self.position),
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)
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}
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'}' => {
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self.position += 1;
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(
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Token::RightCurlyBrace,
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Span(self.position - 1, self.position),
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)
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}
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'/' => {
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if let Some('=') = self.peek_second_char() {
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self.position += 2;
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(Token::SlashEqual, Span(self.position - 2, self.position))
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} else {
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self.position += 1;
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(Token::Slash, Span(self.position - 1, self.position))
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}
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}
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'%' => {
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self.position += 1;
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(Token::Percent, Span(self.position - 1, self.position))
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}
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'&' => {
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if let Some('&') = self.peek_second_char() {
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self.position += 2;
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(
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Token::DoubleAmpersand,
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Span(self.position - 2, self.position),
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)
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} else {
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self.position += 1;
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return Err(LexError::UnexpectedCharacter {
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actual: c,
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position: self.position,
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});
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}
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}
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';' => {
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self.position += 1;
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(Token::Semicolon, Span(self.position - 1, self.position))
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}
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'|' => {
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if let Some('|') = self.peek_second_char() {
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self.position += 2;
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(Token::DoublePipe, Span(self.position - 2, self.position))
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} else {
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self.position += 1;
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return Err(LexError::UnexpectedCharacter {
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actual: c,
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position: self.position,
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});
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}
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}
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'!' => {
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self.position += 1;
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if let Some('=') = self.peek_char() {
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self.position += 1;
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(Token::BangEqual, Span(self.position - 2, self.position))
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} else {
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(Token::Bang, Span(self.position - 1, self.position))
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}
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}
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':' => {
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self.position += 1;
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(Token::Colon, Span(self.position - 1, self.position))
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}
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_ => {
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return Err(LexError::UnexpectedCharacter {
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actual: c,
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position: self.position,
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});
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}
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}
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} else {
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(Token::Eof, Span(self.position, self.position))
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};
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Ok((token, span))
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}
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/// Peek at the next token without consuming the source.
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pub fn peek_token(&mut self) -> Result<(Token<'src>, Span), LexError> {
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let token = self.next_token()?;
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self.position -= token.0.len();
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Ok(token)
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}
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/// Progress to the next character.
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fn next_char(&mut self) -> Option<char> {
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if let Some(c) = self.source[self.position..].chars().next() {
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self.position += c.len_utf8();
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Some(c)
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} else {
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None
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}
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}
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/// Skip whitespace characters.
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fn skip_whitespace(&mut self) {
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while let Some(c) = self.peek_char() {
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if c.is_whitespace() {
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self.next_char();
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} else {
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break;
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}
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}
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}
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/// Peek at the next character without consuming it.
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fn peek_char(&self) -> Option<char> {
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self.source[self.position..].chars().next()
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}
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/// Peek at the second-to-next character without consuming it.
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fn peek_second_char(&self) -> Option<char> {
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self.source[self.position..].chars().nth(1)
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}
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/// Peek the next `n` characters without consuming them.
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fn peek_chars(&self, n: usize) -> &'src str {
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let remaining_source = &self.source[self.position..];
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if remaining_source.len() < n {
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remaining_source
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} else {
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&remaining_source[..n]
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}
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}
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/// Lex an integer or float token.
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fn lex_numeric(&mut self) -> Result<(Token<'src>, Span), LexError> {
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let start_pos = self.position;
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let mut is_float = false;
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let peek_char = self.peek_char();
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if let Some('-') = peek_char {
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self.next_char();
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}
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if let Some('0') = peek_char {
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self.next_char();
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if let Some('x') = self.peek_char() {
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self.next_char();
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let mut peek_chars = self.peek_chars(2).chars();
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match (peek_chars.next(), peek_chars.next()) {
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(Some('0'..='9' | 'A'..='f'), Some('0'..='9' | 'A'..='f')) => {
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self.next_char();
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self.next_char();
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let text = &self.source[start_pos..self.position];
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return Ok((Token::Byte(text), Span(start_pos, self.position)));
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}
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(Some('0'..='9' | 'A'..='f'), erroneous) => {
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self.next_char();
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return Err(LexError::ExpectedAsciiHexDigit {
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actual: erroneous,
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position: self.position,
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});
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}
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(erroneous, _) => {
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return Err(LexError::ExpectedAsciiHexDigit {
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actual: erroneous,
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position: self.position,
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});
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}
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}
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}
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}
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while let Some(c) = self.peek_char() {
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if c == '.' {
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if let Some('0'..='9') = self.peek_second_char() {
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if !is_float {
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self.next_char();
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}
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is_float = true;
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self.next_char();
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while let Some(peek_char) = self.peek_char() {
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if peek_char == ' ' {
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break;
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}
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if let '0'..='9' = peek_char {
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self.next_char();
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continue;
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}
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let peek_second_char = self.peek_second_char();
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if let ('e', Some('0'..='9')) = (peek_char, peek_second_char) {
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self.next_char();
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self.next_char();
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continue;
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}
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if let ('e', Some('-')) = (peek_char, peek_second_char) {
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self.next_char();
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self.next_char();
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continue;
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}
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return Err(LexError::ExpectedCharacterMultiple {
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expected: &['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'e', '-'],
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actual: peek_char,
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position: self.position,
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});
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}
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} else {
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break;
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}
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}
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|
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if c.is_ascii_digit() {
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self.next_char();
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} else {
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break;
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}
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}
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let text = &self.source[start_pos..self.position];
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|
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if is_float {
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Ok((Token::Float(text), Span(start_pos, self.position)))
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} else {
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Ok((Token::Integer(text), Span(start_pos, self.position)))
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}
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}
|
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|
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/// Lex an identifier token.
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fn lex_alphanumeric(&mut self) -> Result<(Token<'src>, Span), LexError> {
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let start_pos = self.position;
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|
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while let Some(c) = self.peek_char() {
|
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if c.is_ascii_alphanumeric() || c == '_' {
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self.next_char();
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} else {
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break;
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}
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}
|
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|
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let string = &self.source[start_pos..self.position];
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let token = match string {
|
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"Infinity" => Token::Float("Infinity"),
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"NaN" => Token::Float("NaN"),
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"async" => Token::Async,
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"bool" => Token::Bool,
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"break" => Token::Break,
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"else" => Token::Else,
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"false" => Token::Boolean("false"),
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"float" => Token::FloatKeyword,
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"if" => Token::If,
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"int" => Token::Int,
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"let" => Token::Let,
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"loop" => Token::Loop,
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"map" => Token::Map,
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"mut" => Token::Mut,
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"struct" => Token::Struct,
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"true" => Token::Boolean("true"),
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"while" => Token::While,
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_ => Token::Identifier(string),
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};
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|
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Ok((token, Span(start_pos, self.position)))
|
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}
|
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|
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fn lex_string(&mut self) -> Result<(Token<'src>, Span), LexError> {
|
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let start_pos = self.position;
|
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|
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self.next_char();
|
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|
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while let Some(c) = self.peek_char() {
|
|
if c == '"' {
|
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self.next_char();
|
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break;
|
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} else {
|
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self.next_char();
|
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}
|
|
}
|
|
|
|
let text = &self.source[start_pos + 1..self.position - 1];
|
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|
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Ok((Token::String(text), Span(start_pos, self.position)))
|
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}
|
|
}
|
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|
|
#[derive(Debug, PartialEq, Clone)]
|
|
pub enum LexError {
|
|
ExpectedAsciiHexDigit {
|
|
actual: Option<char>,
|
|
position: usize,
|
|
},
|
|
ExpectedCharacter {
|
|
expected: char,
|
|
actual: char,
|
|
position: usize,
|
|
},
|
|
ExpectedCharacterMultiple {
|
|
expected: &'static [char],
|
|
actual: char,
|
|
position: usize,
|
|
},
|
|
UnexpectedCharacter {
|
|
actual: char,
|
|
position: usize,
|
|
},
|
|
UnexpectedEndOfFile {
|
|
position: usize,
|
|
},
|
|
}
|
|
|
|
impl AnnotatedError for LexError {
|
|
fn title() -> &'static str {
|
|
"Lex Error"
|
|
}
|
|
|
|
fn description(&self) -> &'static str {
|
|
match self {
|
|
Self::ExpectedAsciiHexDigit { .. } => "Expected ASCII hex digit",
|
|
Self::ExpectedCharacter { .. } => "Expected character",
|
|
Self::ExpectedCharacterMultiple { .. } => "Expected one of multiple characters",
|
|
Self::UnexpectedCharacter { .. } => "Unexpected character",
|
|
Self::UnexpectedEndOfFile { .. } => "Unexpected end of file",
|
|
}
|
|
}
|
|
|
|
fn details(&self) -> Option<String> {
|
|
match self {
|
|
Self::ExpectedAsciiHexDigit { actual, .. } => Some(format!(
|
|
"Expected ASCII hex digit (0-9 or A-F), found \"{}\"",
|
|
actual
|
|
.map(|character| character.to_string())
|
|
.unwrap_or("end of input".to_string())
|
|
)),
|
|
Self::ExpectedCharacter {
|
|
expected, actual, ..
|
|
} => Some(format!(
|
|
"Expected character \"{}\", found \"{}\"",
|
|
expected, actual
|
|
)),
|
|
Self::ExpectedCharacterMultiple {
|
|
expected, actual, ..
|
|
} => {
|
|
let mut details = "Expected one of the following characters ".to_string();
|
|
|
|
for (i, c) in expected.iter().enumerate() {
|
|
if i == expected.len() - 1 {
|
|
details.push_str(", or ");
|
|
} else if i > 0 {
|
|
details.push_str(", ");
|
|
}
|
|
details.push(*c);
|
|
}
|
|
|
|
details.push_str(&format!(" but found {}", actual));
|
|
|
|
Some(details)
|
|
}
|
|
Self::UnexpectedCharacter { actual, .. } => {
|
|
Some(format!("Unexpected character \"{}\"", actual))
|
|
}
|
|
Self::UnexpectedEndOfFile { .. } => Some("Unexpected end of file".to_string()),
|
|
}
|
|
}
|
|
|
|
fn position(&self) -> Span {
|
|
match self {
|
|
Self::ExpectedAsciiHexDigit { position, .. } => Span(*position, *position),
|
|
Self::ExpectedCharacter { position, .. } => Span(*position, *position),
|
|
Self::ExpectedCharacterMultiple { position, .. } => Span(*position, *position),
|
|
Self::UnexpectedCharacter { position, .. } => Span(*position, *position),
|
|
Self::UnexpectedEndOfFile { position } => Span(*position, *position),
|
|
}
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use super::*;
|
|
|
|
#[test]
|
|
fn character() {
|
|
let input = "'a'";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Character('a'), Span(0, 3)),
|
|
(Token::Eof, Span(3, 3)),
|
|
])
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn map_expression() {
|
|
let input = "map { x = \"1\", y = 2, z = 3.0 }";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Map, Span(0, 3)),
|
|
(Token::LeftCurlyBrace, Span(4, 5)),
|
|
(Token::Identifier("x"), Span(6, 7)),
|
|
(Token::Equal, Span(8, 9)),
|
|
(Token::String("1"), Span(10, 13)),
|
|
(Token::Comma, Span(13, 14)),
|
|
(Token::Identifier("y"), Span(15, 16)),
|
|
(Token::Equal, Span(17, 18)),
|
|
(Token::Integer("2"), Span(19, 20)),
|
|
(Token::Comma, Span(20, 21)),
|
|
(Token::Identifier("z"), Span(22, 23)),
|
|
(Token::Equal, Span(24, 25)),
|
|
(Token::Float("3.0"), Span(26, 29)),
|
|
(Token::RightCurlyBrace, Span(30, 31)),
|
|
(Token::Eof, Span(31, 31)),
|
|
])
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn let_statement() {
|
|
let input = "let x = 42";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Let, Span(0, 3)),
|
|
(Token::Identifier("x"), Span(4, 5)),
|
|
(Token::Equal, Span(6, 7)),
|
|
(Token::Integer("42"), Span(8, 10)),
|
|
(Token::Eof, Span(10, 10)),
|
|
])
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn unit_struct() {
|
|
let input = "struct Foo";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Struct, Span(0, 6)),
|
|
(Token::Identifier("Foo"), Span(7, 10)),
|
|
(Token::Eof, Span(10, 10)),
|
|
])
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn tuple_struct() {
|
|
let input = "struct Foo(int, float)";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Struct, Span(0, 6)),
|
|
(Token::Identifier("Foo"), Span(7, 10)),
|
|
(Token::LeftParenthesis, Span(10, 11)),
|
|
(Token::Int, Span(11, 14)),
|
|
(Token::Comma, Span(14, 15)),
|
|
(Token::FloatKeyword, Span(16, 21)),
|
|
(Token::RightParenthesis, Span(21, 22)),
|
|
(Token::Eof, Span(22, 22))
|
|
])
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn fields_struct() {
|
|
let input = "struct FooBar { foo: int, bar: float }";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Struct, Span(0, 6)),
|
|
(Token::Identifier("FooBar"), Span(7, 13)),
|
|
(Token::LeftCurlyBrace, Span(14, 15)),
|
|
(Token::Identifier("foo"), Span(16, 19)),
|
|
(Token::Colon, Span(19, 20)),
|
|
(Token::Int, Span(21, 24)),
|
|
(Token::Comma, Span(24, 25)),
|
|
(Token::Identifier("bar"), Span(26, 29)),
|
|
(Token::Colon, Span(29, 30)),
|
|
(Token::FloatKeyword, Span(31, 36)),
|
|
(Token::RightCurlyBrace, Span(37, 38)),
|
|
(Token::Eof, Span(38, 38))
|
|
])
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn list_index() {
|
|
let input = "[1, 2, 3][1]";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::LeftSquareBrace, Span(0, 1)),
|
|
(Token::Integer("1"), Span(1, 2)),
|
|
(Token::Comma, Span(2, 3)),
|
|
(Token::Integer("2"), Span(4, 5)),
|
|
(Token::Comma, Span(5, 6)),
|
|
(Token::Integer("3"), Span(7, 8)),
|
|
(Token::RightSquareBrace, Span(8, 9)),
|
|
(Token::LeftSquareBrace, Span(9, 10)),
|
|
(Token::Integer("1"), Span(10, 11)),
|
|
(Token::RightSquareBrace, Span(11, 12)),
|
|
(Token::Eof, Span(12, 12)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn list() {
|
|
let input = "[1, 2, 3]";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::LeftSquareBrace, Span(0, 1)),
|
|
(Token::Integer("1"), Span(1, 2)),
|
|
(Token::Comma, Span(2, 3)),
|
|
(Token::Integer("2"), Span(4, 5)),
|
|
(Token::Comma, Span(5, 6)),
|
|
(Token::Integer("3"), Span(7, 8)),
|
|
(Token::RightSquareBrace, Span(8, 9)),
|
|
(Token::Eof, Span(9, 9)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn map_field_access() {
|
|
let input = "{a = 1, b = 2, c = 3}.c";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::LeftCurlyBrace, Span(0, 1)),
|
|
(Token::Identifier("a"), Span(1, 2)),
|
|
(Token::Equal, Span(3, 4)),
|
|
(Token::Integer("1"), Span(5, 6)),
|
|
(Token::Comma, Span(6, 7)),
|
|
(Token::Identifier("b"), Span(8, 9)),
|
|
(Token::Equal, Span(10, 11)),
|
|
(Token::Integer("2"), Span(12, 13)),
|
|
(Token::Comma, Span(13, 14)),
|
|
(Token::Identifier("c"), Span(15, 16)),
|
|
(Token::Equal, Span(17, 18)),
|
|
(Token::Integer("3"), Span(19, 20)),
|
|
(Token::RightCurlyBrace, Span(20, 21)),
|
|
(Token::Dot, Span(21, 22)),
|
|
(Token::Identifier("c"), Span(22, 23)),
|
|
(Token::Eof, Span(23, 23)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn range() {
|
|
let input = "0..42";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("0"), Span(0, 1)),
|
|
(Token::DoubleDot, Span(1, 3)),
|
|
(Token::Integer("42"), Span(3, 5)),
|
|
(Token::Eof, Span(5, 5))
|
|
])
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn negate_expression() {
|
|
let input = "x = -42; -x";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Identifier("x"), Span(0, 1)),
|
|
(Token::Equal, Span(2, 3)),
|
|
(Token::Integer("-42"), Span(4, 7)),
|
|
(Token::Semicolon, Span(7, 8)),
|
|
(Token::Minus, Span(9, 10)),
|
|
(Token::Identifier("x"), Span(10, 11)),
|
|
(Token::Eof, Span(11, 11))
|
|
])
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn not_expression() {
|
|
let input = "!true; !false";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Bang, Span(0, 1)),
|
|
(Token::Boolean("true"), Span(1, 5)),
|
|
(Token::Semicolon, Span(5, 6)),
|
|
(Token::Bang, Span(7, 8)),
|
|
(Token::Boolean("false"), Span(8, 13)),
|
|
(Token::Eof, Span(13, 13))
|
|
])
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn if_else() {
|
|
let input = "if x < 10 { x + 1 } else { x }";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::If, Span(0, 2)),
|
|
(Token::Identifier("x"), Span(3, 4)),
|
|
(Token::Less, Span(5, 6)),
|
|
(Token::Integer("10"), Span(7, 9)),
|
|
(Token::LeftCurlyBrace, Span(10, 11)),
|
|
(Token::Identifier("x"), Span(12, 13)),
|
|
(Token::Plus, Span(14, 15)),
|
|
(Token::Integer("1"), Span(16, 17)),
|
|
(Token::RightCurlyBrace, Span(18, 19)),
|
|
(Token::Else, Span(20, 24)),
|
|
(Token::LeftCurlyBrace, Span(25, 26)),
|
|
(Token::Identifier("x"), Span(27, 28)),
|
|
(Token::RightCurlyBrace, Span(29, 30)),
|
|
(Token::Eof, Span(30, 30)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn while_loop() {
|
|
let input = "while x < 10 { x += 1 }";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::While, Span(0, 5)),
|
|
(Token::Identifier("x"), Span(6, 7)),
|
|
(Token::Less, Span(8, 9)),
|
|
(Token::Integer("10"), Span(10, 12)),
|
|
(Token::LeftCurlyBrace, Span(13, 14)),
|
|
(Token::Identifier("x"), Span(15, 16)),
|
|
(Token::PlusEqual, Span(17, 19)),
|
|
(Token::Integer("1"), Span(20, 21)),
|
|
(Token::RightCurlyBrace, Span(22, 23)),
|
|
(Token::Eof, Span(23, 23)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn add_assign() {
|
|
let input = "x += 42";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Identifier("x"), Span(0, 1)),
|
|
(Token::PlusEqual, Span(2, 4)),
|
|
(Token::Integer("42"), Span(5, 7)),
|
|
(Token::Eof, Span(7, 7)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn or() {
|
|
let input = "true || false";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Boolean("true"), Span(0, 4)),
|
|
(Token::DoublePipe, Span(5, 7)),
|
|
(Token::Boolean("false"), Span(8, 13)),
|
|
(Token::Eof, Span(13, 13)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn block() {
|
|
let input = "{ x = 42; y = \"foobar\" }";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::LeftCurlyBrace, Span(0, 1)),
|
|
(Token::Identifier("x"), Span(2, 3)),
|
|
(Token::Equal, Span(4, 5)),
|
|
(Token::Integer("42"), Span(6, 8)),
|
|
(Token::Semicolon, Span(8, 9)),
|
|
(Token::Identifier("y"), Span(10, 11)),
|
|
(Token::Equal, Span(12, 13)),
|
|
(Token::String("foobar"), Span(14, 22)),
|
|
(Token::RightCurlyBrace, Span(23, 24)),
|
|
(Token::Eof, Span(24, 24)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn not_equal() {
|
|
let input = "42 != 42";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("42"), Span(0, 2)),
|
|
(Token::BangEqual, Span(3, 5)),
|
|
(Token::Integer("42"), Span(6, 8)),
|
|
(Token::Eof, Span(8, 8)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn equal() {
|
|
let input = "42 == 42";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("42"), Span(0, 2)),
|
|
(Token::DoubleEqual, Span(3, 5)),
|
|
(Token::Integer("42"), Span(6, 8)),
|
|
(Token::Eof, Span(8, 8)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn modulo() {
|
|
let input = "42 % 2";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("42"), Span(0, 2)),
|
|
(Token::Percent, Span(3, 4)),
|
|
(Token::Integer("2"), Span(5, 6)),
|
|
(Token::Eof, Span(6, 6)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn divide() {
|
|
let input = "42 / 2";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("42"), Span(0, 2)),
|
|
(Token::Slash, Span(3, 4)),
|
|
(Token::Integer("2"), Span(5, 6)),
|
|
(Token::Eof, Span(6, 6)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn greater_than() {
|
|
let input = ">";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![(Token::Greater, Span(0, 1)), (Token::Eof, Span(1, 1))])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn greater_than_or_equal() {
|
|
let input = ">=";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::GreaterEqual, Span(0, 2)),
|
|
(Token::Eof, Span(2, 2))
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn less_than() {
|
|
let input = "<";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![(Token::Less, Span(0, 1)), (Token::Eof, Span(1, 1))])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn less_than_or_equal() {
|
|
let input = "<=";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::LessEqual, Span(0, 2)),
|
|
(Token::Eof, Span(2, 2))
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn infinity() {
|
|
let input = "Infinity";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Float("Infinity"), Span(0, 8)),
|
|
(Token::Eof, Span(8, 8)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn negative_infinity() {
|
|
let input = "-Infinity";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Float("-Infinity"), Span(0, 9)),
|
|
(Token::Eof, Span(9, 9)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn nan() {
|
|
let input = "NaN";
|
|
|
|
assert!(lex(input).is_ok_and(|tokens| tokens[0].0 == Token::Float("NaN")));
|
|
}
|
|
|
|
#[test]
|
|
fn complex_float() {
|
|
let input = "42.42e42";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Float("42.42e42"), Span(0, 8)),
|
|
(Token::Eof, Span(8, 8)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn max_integer() {
|
|
let input = "9223372036854775807";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("9223372036854775807"), Span(0, 19)),
|
|
(Token::Eof, Span(19, 19)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn min_integer() {
|
|
let input = "-9223372036854775808";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("-9223372036854775808"), Span(0, 20)),
|
|
(Token::Eof, Span(20, 20)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn subtract_negative_integers() {
|
|
let input = "-42 - -42";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("-42"), Span(0, 3)),
|
|
(Token::Minus, Span(4, 5)),
|
|
(Token::Integer("-42"), Span(6, 9)),
|
|
(Token::Eof, Span(9, 9)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn negative_integer() {
|
|
let input = "-42";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("-42"), Span(0, 3)),
|
|
(Token::Eof, Span(3, 3))
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn read_line() {
|
|
let input = "read_line()";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Identifier("read_line"), Span(0, 9)),
|
|
(Token::LeftParenthesis, Span(9, 10)),
|
|
(Token::RightParenthesis, Span(10, 11)),
|
|
(Token::Eof, Span(11, 11)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn write_line() {
|
|
let input = "write_line(\"Hello, world!\")";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Identifier("write_line"), Span(0, 10)),
|
|
(Token::LeftParenthesis, Span(10, 11)),
|
|
(Token::String("Hello, world!"), Span(11, 26)),
|
|
(Token::RightParenthesis, Span(26, 27)),
|
|
(Token::Eof, Span(27, 27)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn string_concatenation() {
|
|
let input = "\"Hello, \" + \"world!\"";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::String("Hello, "), Span(0, 9)),
|
|
(Token::Plus, Span(10, 11)),
|
|
(Token::String("world!"), Span(12, 20)),
|
|
(Token::Eof, Span(20, 20)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn string() {
|
|
let input = "\"Hello, world!\"";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::String("Hello, world!"), Span(0, 15)),
|
|
(Token::Eof, Span(15, 15)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn r#true() {
|
|
let input = "true";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Boolean("true"), Span(0, 4)),
|
|
(Token::Eof, Span(4, 4)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn r#false() {
|
|
let input = "false";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Boolean("false"), Span(0, 5)),
|
|
(Token::Eof, Span(5, 5))
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn property_access_function_call() {
|
|
let input = "42.is_even()";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("42"), Span(0, 2)),
|
|
(Token::Dot, Span(2, 3)),
|
|
(Token::Identifier("is_even"), Span(3, 10)),
|
|
(Token::LeftParenthesis, Span(10, 11)),
|
|
(Token::RightParenthesis, Span(11, 12)),
|
|
(Token::Eof, Span(12, 12)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn empty() {
|
|
let input = "";
|
|
|
|
assert_eq!(lex(input), Ok(vec![(Token::Eof, Span(0, 0))]))
|
|
}
|
|
|
|
#[test]
|
|
fn reserved_identifier() {
|
|
let input = "length";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Identifier("length"), Span(0, 6)),
|
|
(Token::Eof, Span(6, 6)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn square_braces() {
|
|
let input = "[]";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::LeftSquareBrace, Span(0, 1)),
|
|
(Token::RightSquareBrace, Span(1, 2)),
|
|
(Token::Eof, Span(2, 2)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn small_float() {
|
|
let input = "1.23";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Float("1.23"), Span(0, 4)),
|
|
(Token::Eof, Span(4, 4)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
#[allow(clippy::excessive_precision)]
|
|
fn big_float() {
|
|
let input = "123456789.123456789";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Float("123456789.123456789"), Span(0, 19)),
|
|
(Token::Eof, Span(19, 19)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn float_with_exponent() {
|
|
let input = "1.23e4";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Float("1.23e4"), Span(0, 6)),
|
|
(Token::Eof, Span(6, 6)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn float_with_negative_exponent() {
|
|
let input = "1.23e-4";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Float("1.23e-4"), Span(0, 7)),
|
|
(Token::Eof, Span(7, 7)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn float_infinity_and_nan() {
|
|
let input = "Infinity -Infinity NaN";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Float("Infinity"), Span(0, 8)),
|
|
(Token::Float("-Infinity"), Span(9, 18)),
|
|
(Token::Float("NaN"), Span(19, 22)),
|
|
(Token::Eof, Span(22, 22)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn add() {
|
|
let input = "1 + 2";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("1"), Span(0, 1)),
|
|
(Token::Plus, Span(2, 3)),
|
|
(Token::Integer("2"), Span(4, 5)),
|
|
(Token::Eof, Span(5, 5)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn multiply() {
|
|
let input = "1 * 2";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("1"), Span(0, 1)),
|
|
(Token::Star, Span(2, 3)),
|
|
(Token::Integer("2"), Span(4, 5)),
|
|
(Token::Eof, Span(5, 5)),
|
|
])
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn add_and_multiply() {
|
|
let input = "1 + 2 * 3";
|
|
|
|
assert_eq!(
|
|
lex(input),
|
|
Ok(vec![
|
|
(Token::Integer("1"), Span(0, 1)),
|
|
(Token::Plus, Span(2, 3)),
|
|
(Token::Integer("2"), Span(4, 5)),
|
|
(Token::Star, Span(6, 7)),
|
|
(Token::Integer("3"), Span(8, 9)),
|
|
(Token::Eof, Span(9, 9)),
|
|
])
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn assignment() {
|
|
let input = "a = 1 + 2 * 3";
|
|
|
|
assert_eq!(
|
|
lex(input,),
|
|
Ok(vec![
|
|
(Token::Identifier("a"), Span(0, 1)),
|
|
(Token::Equal, Span(2, 3)),
|
|
(Token::Integer("1"), Span(4, 5)),
|
|
(Token::Plus, Span(6, 7)),
|
|
(Token::Integer("2"), Span(8, 9)),
|
|
(Token::Star, Span(10, 11)),
|
|
(Token::Integer("3"), Span(12, 13)),
|
|
(Token::Eof, Span(13, 13)),
|
|
])
|
|
);
|
|
}
|
|
}
|