Lex float types

src/lexer/error.rs

@@ -7,6 +7,7 @@ pub type LexingError = crate::error::ErrorLocationWrapper<LexingErrorKind>;
 pub enum LexingErrorKind {
 	UnmatchedQuote,
 	IntPrimitiveTooBig,
+	InvalidFloat,
 	UnexpectedCharacter(char),
 }
 
@@ -18,6 +19,7 @@ impl fmt::Display for LexingErrorKind {
 			LexingErrorKind::IntPrimitiveTooBig => {
 				write!(f, "Integer too large. Max value is i32_max({})", i32::MAX)
 			}
+			LexingErrorKind::InvalidFloat => write!(f, "Invalid float literal"),
 		}
 	}
 }

src/lexer/lexer_iter.rs

@@ -40,6 +40,22 @@ impl<'a> LexerIter<'a> {
 		self.inner.as_str()
 	}
 
+	pub fn as_str_while<F: FnMut(char) -> bool>(&mut self, mut predicate: F) -> &'a str {
+		let str = self.inner.as_str();
+		let mut end_indice = 0;
+		for (i, c) in str.char_indices() {
+			end_indice = i;
+			if !predicate(c) {
+				break;
+			}
+		}
+		unsafe {
+			self.inner = str.get_unchecked(end_indice..).chars();
+			let res = str.get_unchecked(0..end_indice);
+			res
+		}
+	}
+
 	pub fn next_if(&mut self, func: impl FnOnce(char) -> bool) -> Option<char> {
 		if func(self.peek()?) {
 			self.next()

src/lexer/mod.rs

@@ -1,6 +1,7 @@
 mod error;
 mod lexer_iter;
 pub mod token;
+
 use lexer_iter::LexerIter;
 
 pub use error::LexingError;
@@ -29,14 +30,16 @@ impl<'a, 'b> Lexer<'a, 'b> {
 
 		while self.source_iter.peek().is_some() {
 			match self.scan_token() {
-				Ok(Some(token)) => if let Ok(ref mut v) = res { 
-					v.push(token)
+				Ok(Some(token)) => {
+					if let Ok(ref mut v) = res {
+						v.push(token)
+					}
 				}
 				Ok(None) => (),
 				Err(e) => match res {
 					Ok(_) => res = Err(vec![e]),
-					Err(ref mut v) => v.push(e)
-				}
+					Err(ref mut v) => v.push(e),
+				},
 			}
 		}
 
@@ -73,75 +76,42 @@ impl<'a, 'b> Lexer<'a, 'b> {
 	}
 
 	fn scan_token(&mut self) -> Result<Option<Token<'b>>, LexingError> {
-		Ok(Some(match self.source_iter.next().unwrap() {
-			'(' => self.get_token(token::TokenType::LeftParen),
-			')' => self.get_token(token::TokenType::RightParen),
-			'{' => self.get_token(token::TokenType::LeftBrace),
-			'}' => self.get_token(token::TokenType::RightBrace),
-			',' => self.get_token(token::TokenType::Comma),
-			'.' => self.get_token(token::TokenType::Dot),
-			'-' => self.get_token(token::TokenType::Minus),
-			'+' => self.get_token(token::TokenType::Plus),
-			';' => self.get_token(token::TokenType::Semicolon),
-			'*' => self.get_token(token::TokenType::Star),
-			'/' => self.get_token(token::TokenType::Slash),
-			'!' => self.get_token_if_next_eq_or(
-				'=',
-				token::TokenType::BangEqual,
-				token::TokenType::Bang,
-			),
-			'=' => self.get_token_if_next_eq_or(
-				'=',
-				token::TokenType::EqualEqual,
-				token::TokenType::Equal,
-			),
-			'<' => self.get_token_if_next_eq_or(
-				'=',
-				token::TokenType::LessEqual,
-				token::TokenType::Less,
-			),
-			'>' => self.get_token_if_next_eq_or(
-				'=',
-				token::TokenType::GreaterEqual,
-				token::TokenType::Greater,
-			),
-			'"' => {
-				let mut string = String::new();
-				let unmatched_char_error = Err(self.get_error(LexingErrorKind::UnmatchedQuote));
-				loop {
-					let next_char = self.source_iter.next();
-					match next_char {
-						Some('"') => break,
-						Some('\\') => match self.source_iter.next() {
-							Some(c) => string.push(c),
-							None => return unmatched_char_error,
-						},
-						Some(c) => string.push(c),
-						None => return unmatched_char_error,
+		Ok(Some(match self.source_iter.peek().unwrap() {
+			'0'..='9' => {
+				let mut found_period = false;
+				let num_str = self.source_iter.as_str_while(|c| {
+					if c == '.' {
+						// Already found a period finish parsing the float
+						if found_period {
+							return false;
+						}
+						found_period = true;
 					}
-				}
-				self.get_token(token::TokenType::String(string))
-			}
-			c @ '0'..='9' => {
-				let mut num: i32 = c.to_digit(10).unwrap() as i32;
-				while let Some(c) = self.source_iter.next_if(|c| c.is_digit(10)) {
-					let int_primitive_too_big_err =
-						|| self.get_error(LexingErrorKind::IntPrimitiveTooBig);
-					num = num.checked_mul(10).ok_or_else(int_primitive_too_big_err)?;
-					num = num
-						.checked_add(c.to_digit(10).unwrap() as i32)
-						.ok_or_else(int_primitive_too_big_err)?;
-				}
-				self.get_token(token::TokenType::Int(num))
-			}
-			c @ 'a'..='z' | c @ 'A'..='Z' => {
-				let mut identifier = String::new();
-				identifier.push(c);
-				while let Some(c) = self.source_iter.next_if(|c| c.is_alphanumeric()) {
-					identifier.push(c);
-				}
+					c.is_digit(10) || c == '.'
+				});
+				let res = if found_period {
+					num_str
+						.parse::<f32>()
+						.map(|v| self.get_token(token::TokenType::Float(v)))
+						.map_err(|_| LexingErrorKind::InvalidFloat)
+				} else {
+					num_str
+						.parse::<i32>()
+						.map(|v| self.get_token(token::TokenType::Int(v)))
+						.map_err(|_| LexingErrorKind::IntPrimitiveTooBig)
+				};
+				return res.map(|v| Some(v)).map_err(|e| self.get_error(e))
+				/*
 
-				self.get_token(match identifier.as_str() {
+					Err(IntErrorKind::PosOverflow) | Err(IntErrorKind::NegOverflow) => return Err(self.get_error(LexingErrorKind::IntPrimitiveTooBig)),
+					_ => unreachable!(),
+				}
+				*/
+			}
+			'a'..='z' | 'A'..='Z' => {
+				let identifier = self.source_iter.as_str_while(|c| c.is_alphanumeric());
+
+				self.get_token(match identifier {
 					"and" => token::TokenType::And,
 					"else" => token::TokenType::Else,
 					"false" => token::TokenType::False,
@@ -155,12 +125,62 @@ impl<'a, 'b> Lexer<'a, 'b> {
 					"let" => token::TokenType::Let,
 					"While" => token::TokenType::While,
 					"or" => token::TokenType::Or,
-					_ => token::TokenType::Identifier(identifier),
+					_ => token::TokenType::Identifier(identifier.to_string()),
 				})
 			}
-			// Ignore whitespace
-			' ' | '\r' | '\t' | '\n' => return Ok(None),
-			c => return Err(self.get_error(LexingErrorKind::UnexpectedCharacter(c))),
+			_ => match self.source_iter.next().unwrap() {
+				'(' => self.get_token(token::TokenType::LeftParen),
+				')' => self.get_token(token::TokenType::RightParen),
+				'{' => self.get_token(token::TokenType::LeftBrace),
+				'}' => self.get_token(token::TokenType::RightBrace),
+				',' => self.get_token(token::TokenType::Comma),
+				'.' => self.get_token(token::TokenType::Dot),
+				'-' => self.get_token(token::TokenType::Minus),
+				'+' => self.get_token(token::TokenType::Plus),
+				';' => self.get_token(token::TokenType::Semicolon),
+				'*' => self.get_token(token::TokenType::Star),
+				'/' => self.get_token(token::TokenType::Slash),
+				'!' => self.get_token_if_next_eq_or(
+					'=',
+					token::TokenType::BangEqual,
+					token::TokenType::Bang,
+				),
+				'=' => self.get_token_if_next_eq_or(
+					'=',
+					token::TokenType::EqualEqual,
+					token::TokenType::Equal,
+				),
+				'<' => self.get_token_if_next_eq_or(
+					'=',
+					token::TokenType::LessEqual,
+					token::TokenType::Less,
+				),
+				'>' => self.get_token_if_next_eq_or(
+					'=',
+					token::TokenType::GreaterEqual,
+					token::TokenType::Greater,
+				),
+				'"' => {
+					let mut string = String::new();
+					let unmatched_char_error = Err(self.get_error(LexingErrorKind::UnmatchedQuote));
+					loop {
+						let next_char = self.source_iter.next();
+						match next_char {
+							Some('"') => break,
+							Some('\\') => match self.source_iter.next() {
+								Some(c) => string.push(c),
+								None => return unmatched_char_error,
+							},
+							Some(c) => string.push(c),
+							None => return unmatched_char_error,
+						}
+					}
+					self.get_token(token::TokenType::String(string))
+				}
+				// Ignore whitespace
+				' ' | '\r' | '\t' | '\n' => return Ok(None),
+				c => return Err(self.get_error(LexingErrorKind::UnexpectedCharacter(c))),
+			},
 		}))
 	}
 }

test.lox

@@ -1,5 +1,6 @@
-1 == 1;
-1 == 2;
+12 == 1;
 print 1;
+print 1.90 == 1.90;
+print 1.90;
 print 2;
 nil;