some changes

src/lexer.rs

@@ -207,6 +207,18 @@ impl Lexer {
             };
         }
 
+        macro_rules! next_is {
+            ($ch:expr) => {
+                match self.input.get(self.pos + 1) {
+                    Some($ch) => {
+                        self.pos += 1;
+                        true
+                    }
+                    _ => false,
+                }
+            };
+        }
+
         let token = match ch {
             '(' => Some(Token::OpenParan),
             ')' => Some(Token::CloseParan),
@@ -314,24 +326,15 @@ impl Lexer {
                 _ => Symbol::Greater,
             },
             '.' => match self.input.get(self.pos + 1) {
-                Some('.') => match self.input.get(self.pos + 1) {
-                    Some('.') => {
-                        self.pos += 2;
-                        Symbol::TripleDot
-                    }
-                    _ => {
-                        self.pos += 1;
-                        Symbol::DoubleDot
-                    }
+                Some('.') => match next_is!('.') {
+                    true => Symbol::TripleDot,
+                    false => Symbol::DoubleDot,
                 },
                 _ => Symbol::Dot,
             },
-            ':' => match self.input.get(self.pos + 1) {
-                Some(':') => {
-                    self.pos += 1;
-                    Symbol::DoubleColon
-                }
-                _ => Symbol::Colon,
+            ':' => match next_is!(':') {
+                true => Symbol::DoubleColon,
+                false => Symbol::Colon,
             },
             ',' => Symbol::Comma,
             ';' => Symbol::Semicolon,

src/parser.rs

@@ -119,6 +119,20 @@ impl Parser {
                 "bool" => Type::Boolean,
                 _ => return Err(Error::TypeError(format!("unknown type {ident}"))),
             },
+            Token::OpenParan => {
+                let mut tys = vec![];
+                while !self.peek_tok().is_some_and(|tok| tok == &Token::CloseParan) {
+                    tys.push(self.parse_type()?);
+                    
+                    if self.peek_tok() == Some(&Token::Symbol(Symbol::Comma)) {
+                        self.eat(Token::Symbol(Symbol::Comma))?;
+                    } else {
+                        break;
+                    }
+                }
+                self.eat(Token::CloseParan)?;
+                Type::Tuple(tys)
+            },
             _ => todo!(),
         };
         Ok(ty)

test/t7

@@ -0,0 +1,3 @@
+fn main() -> (i32, i32) {
+	(123, 456)
+}