Impl Tuple parsing

compiler/erg_parser/ast.rs

@@ -130,7 +130,7 @@ impl KwArg {
 pub struct Args {
     pos_args: Vec<PosArg>,
     kw_args: Vec<KwArg>,
-    paren: Option<(Token, Token)>,
+    pub paren: Option<(Token, Token)>,
 }
 
 impl NestedDisplay for Args {
@@ -358,6 +358,10 @@ impl Accessor {
         Self::Attr(Attribute::new(obj, name))
     }
 
+    pub fn tuple_attr(obj: Expr, index: Literal) -> Self {
+        Self::TupleAttr(TupleAttribute::new(obj, index))
+    }
+
     pub fn subscr(obj: Expr, index: Expr) -> Self {
         Self::Subscr(Subscript::new(obj, index))
     }
@@ -497,8 +501,10 @@ pub struct NormalTuple {
 }
 
 impl NestedDisplay for NormalTuple {
-    fn fmt_nest(&self, f: &mut fmt::Formatter<'_>, _level: usize) -> fmt::Result {
-        write!(f, "({})", self.elems)
+    fn fmt_nest(&self, f: &mut fmt::Formatter<'_>, level: usize) -> fmt::Result {
+        writeln!(f, "(")?;
+        self.elems.fmt_nest(f, level + 1)?;
+        write!(f, "\n{})", "    ".repeat(level))
     }
 }
 
@@ -507,9 +513,7 @@ impl_locational!(NormalTuple, elems, elems);
 
 impl NormalTuple {
     pub fn new(elems: Args) -> Self {
-        Self {
-            elems,
-        }
+        Self { elems }
     }
 }
 
@@ -765,6 +769,30 @@ impl ConstAttribute {
     }
 }
 
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub struct ConstTupleAttribute {
+    tup: Box<ConstExpr>,
+    index: Literal,
+}
+
+impl NestedDisplay for ConstTupleAttribute {
+    fn fmt_nest(&self, f: &mut fmt::Formatter<'_>, _level: usize) -> fmt::Result {
+        write!(f, "{}.{}", self.tup, self.index)
+    }
+}
+
+impl_display_from_nested!(ConstTupleAttribute);
+impl_locational!(ConstTupleAttribute, tup, index);
+
+impl ConstTupleAttribute {
+    pub fn new(tup: ConstExpr, index: Literal) -> Self {
+        Self {
+            tup: Box::new(tup),
+            index,
+        }
+    }
+}
+
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct ConstSubscript {
     obj: Box<ConstExpr>,
@@ -794,12 +822,13 @@ pub enum ConstAccessor {
     Local(ConstLocal),
     SelfDot(ConstLocal),
     Attr(ConstAttribute),
+    TupleAttr(ConstTupleAttribute),
     Subscr(ConstSubscript),
 }
 
-impl_nested_display_for_enum!(ConstAccessor; Local, SelfDot, Attr, Subscr);
+impl_nested_display_for_enum!(ConstAccessor; Local, SelfDot, Attr, TupleAttr, Subscr);
 impl_display_from_nested!(ConstAccessor);
-impl_locational_for_enum!(ConstAccessor; Local, SelfDot, Attr, Subscr);
+impl_locational_for_enum!(ConstAccessor; Local, SelfDot, Attr, TupleAttr, Subscr);
 
 impl ConstAccessor {
     pub const fn local(symbol: Token) -> Self {

compiler/erg_parser/parse.rs

@@ -659,10 +659,24 @@ impl Parser {
             match self.peek() {
                 Some(t) if t.is(Dot) => {
                     self.skip();
-                    let symbol = self.lpop();
-                    debug_power_assert!(symbol.is(Symbol));
-                    let attr = Local::new(symbol);
-                    acc = Accessor::attr(Expr::Accessor(acc), attr);
+                    let token = self.lpop();
+                    match token.kind {
+                        Symbol => {
+                            let attr = Local::new(token);
+                            acc = Accessor::attr(Expr::Accessor(acc), attr);
+                        }
+                        NatLit => {
+                            let attr = Literal::from(token);
+                            acc = Accessor::tuple_attr(Expr::Accessor(acc), attr);
+                        }
+                        _ => {
+                            self.restore(token);
+                            self.level -= 1;
+                            let err = self.skip_and_throw_syntax_err(caused_by!());
+                            self.errs.push(err);
+                            return Err(());
+                        }
+                    }
                 }
                 Some(t) if t.is(LSqBr) => {
                     self.skip();
@@ -1681,6 +1695,14 @@ impl Parser {
                                 }
                             }
                         }
+                        Some(t) if t.is(Comma) => {
+                            let first_elem = enum_unwrap!(stack.pop(), Some:(ExprOrOp::Expr:(_)));
+                            let tup = self
+                                .try_reduce_tuple(first_elem)
+                                .map_err(|_| self.stack_dec())?;
+                            self.level -= 1;
+                            return Ok(Expr::Tuple(tup));
+                        }
                         _ => {
                             if stack.len() <= 1 {
                                 break;
@@ -1755,9 +1777,24 @@ impl Parser {
                 Ok(Expr::Lambda(lambda))
             }
             Some(t) if t.is(LParen) => {
-                let tuple = self.try_reduce_tuple().map_err(|_| self.stack_dec())?;
+                let lparen = self.lpop();
+                if self.cur_is(RParen) {
+                    let rparen = self.lpop();
+                    let args = Args::new(vec![], vec![], Some((lparen, rparen)));
+                    let unit = Tuple::Normal(NormalTuple::new(args));
+                    self.level -= 1;
+                    return Ok(Expr::Tuple(unit));
+                }
+                let mut expr = self.try_reduce_expr().map_err(|_| self.stack_dec())?;
+                let rparen = self.lpop();
+                match &mut expr {
+                    Expr::Tuple(Tuple::Normal(tup)) => {
+                        tup.elems.paren = Some((lparen, rparen));
+                    }
+                    _ => {}
+                }
                 self.level -= 1;
-                Ok(Expr::Tuple(tuple))
+                Ok(expr)
             }
             Some(t) if t.is(LSqBr) => {
                 let array = self.try_reduce_array().map_err(|_| self.stack_dec())?;
@@ -1852,24 +1889,45 @@ impl Parser {
     }
 
     #[inline]
-    fn try_reduce_tuple(&mut self) -> ParseResult<Tuple> {
+    fn try_reduce_tuple(&mut self, first_elem: Expr) -> ParseResult<Tuple> {
         debug_call_info!(self);
-        self.skip();
-        let inner = self.try_reduce_elems().map_err(|_| self.stack_dec())?;
-        self.skip();
-        let tpl = match inner {
-            ArrayInner::Normal(elems) => {
-                Tuple::Normal(NormalTuple::new(elems))
-                },
-            ArrayInner::Comprehension {
-                elem: _,
-                generators: _,
-                guards: _,
-            } => todo!(),
-            _ => unreachable!(),
-        };
+        let mut args = Args::new(vec![PosArg::new(first_elem)], vec![], None);
+        loop {
+            match self.peek() {
+                Some(t) if t.is(Comma) => {
+                    self.skip();
+                    if self.cur_is(Comma) {
+                        self.level -= 1;
+                        let err = self.skip_and_throw_syntax_err(caused_by!());
+                        self.errs.push(err);
+                        return Err(());
+                    }
+                    match self.try_reduce_arg().map_err(|_| self.stack_dec())? {
+                        PosOrKwArg::Pos(arg) => {
+                            args.push_pos(arg);
+                        }
+                        PosOrKwArg::Kw(_arg) => todo!(),
+                    }
+                }
+                Some(t) if t.is(Newline) => {
+                    while self.cur_is(Newline) {
+                        self.skip();
+                    }
+                    match self.try_reduce_arg().map_err(|_| self.stack_dec())? {
+                        PosOrKwArg::Pos(arg) => {
+                            args.push_pos(arg);
+                        }
+                        PosOrKwArg::Kw(_arg) => todo!(),
+                    }
+                }
+                _ => {
+                    break;
+                }
+            }
+        }
+        let tup = Tuple::Normal(NormalTuple::new(args));
         self.level -= 1;
-        Ok(tpl)
+        Ok(tup)
     }
 
     #[inline]