diff --git a/compiler/erg_compiler/context/instantiate.rs b/compiler/erg_compiler/context/instantiate.rs
index c75e56d0..5132226e 100644
--- a/compiler/erg_compiler/context/instantiate.rs
+++ b/compiler/erg_compiler/context/instantiate.rs
@@ -617,7 +617,11 @@ impl Context {
                 self.instantiate_typespec(lhs, opt_decl_t, tv_ctx, mode)?,
                 self.instantiate_typespec(rhs, opt_decl_t, tv_ctx, mode)?,
             )),
-            TypeSpec::Array { .. } => todo!(),
+            TypeSpec::Array(arr) => {
+                let elem_t = self.instantiate_typespec(&arr.ty, opt_decl_t, tv_ctx, mode)?;
+                let len = self.instantiate_const_expr(&arr.len);
+                Ok(array(elem_t, len))
+            }
             // FIXME: unwrap
             TypeSpec::Tuple(tys) => Ok(tuple(
                 tys.iter()
diff --git a/compiler/erg_parser/ast.rs b/compiler/erg_parser/ast.rs
index 4c215b1a..5f63aa50 100644
--- a/compiler/erg_parser/ast.rs
+++ b/compiler/erg_parser/ast.rs
@@ -1586,6 +1586,15 @@ impl fmt::Display for ArrayTypeSpec {
 
 impl_locational!(ArrayTypeSpec, ty, len);
 
+impl ArrayTypeSpec {
+    pub fn new(ty: TypeSpec, len: ConstExpr) -> Self {
+        Self {
+            ty: Box::new(ty),
+            len,
+        }
+    }
+}
+
 /// * Array: `[Int; 3]`, `[Int, Ratio, Complex]`, etc.
 /// * Dict: `[Str: Str]`, etc.
 /// * And (Intersection type): Add and Sub and Mul (== Num), etc.
diff --git a/compiler/erg_parser/parse.rs b/compiler/erg_parser/parse.rs
index 821b9704..09f25917 100644
--- a/compiler/erg_parser/parse.rs
+++ b/compiler/erg_parser/parse.rs
@@ -2485,6 +2485,25 @@ impl Parser {
                 self.level -= 1;
                 Ok(TypeSpec::Array(array))
             }
+            Expr::BinOp(bin) => {
+                if bin.op.kind.is_range_op() {
+                    let op = bin.op;
+                    let mut args = bin.args.into_iter();
+                    let lhs = self
+                        .validate_const_expr(*args.next().unwrap())
+                        .map_err(|_| self.stack_dec())?;
+                    let rhs = self
+                        .validate_const_expr(*args.next().unwrap())
+                        .map_err(|_| self.stack_dec())?;
+                    self.level -= 1;
+                    Ok(TypeSpec::Interval { op, lhs, rhs })
+                } else {
+                    self.level -= 1;
+                    let err = ParseError::simple_syntax_error(line!() as usize, bin.loc());
+                    self.errs.push(err);
+                    Err(())
+                }
+            }
             other => {
                 self.level -= 1;
                 let err = ParseError::simple_syntax_error(line!() as usize, other.loc());
@@ -2586,8 +2605,27 @@ impl Parser {
         ))
     }
 
-    fn convert_array_to_array_type_spec(&mut self, _array: Array) -> ParseResult<ArrayTypeSpec> {
+    fn convert_array_to_array_type_spec(&mut self, array: Array) -> ParseResult<ArrayTypeSpec> {
         debug_call_info!(self);
-        todo!()
+        match array {
+            Array::Normal(arr) => {
+                // TODO: add hint
+                self.errs
+                    .push(ParseError::simple_syntax_error(line!() as usize, arr.loc()));
+                Err(())
+            }
+            Array::WithLength(arr) => {
+                let t_spec = self.convert_rhs_to_type_spec(arr.elem.expr)?;
+                let len = self.validate_const_expr(*arr.len)?;
+                self.level -= 1;
+                Ok(ArrayTypeSpec::new(t_spec, len))
+            }
+            Array::Comprehension(arr) => {
+                // TODO: add hint
+                self.errs
+                    .push(ParseError::simple_syntax_error(line!() as usize, arr.loc()));
+                Err(())
+            }
+        }
     }
 }
diff --git a/compiler/erg_parser/token.rs b/compiler/erg_parser/token.rs
index b59efee1..451657aa 100644
--- a/compiler/erg_parser/token.rs
+++ b/compiler/erg_parser/token.rs
@@ -265,6 +265,10 @@ impl TokenKind {
             FuncArrow | ProcArrow | Equal /* | PreDollar | PreAt */
         )
     }
+
+    pub const fn is_range_op(&self) -> bool {
+        matches!(self, Closed | LeftOpen | RightOpen | Open)
+    }
 }
 
 impl fmt::Display for TokenKind {