From df0fba34bd764fe7bbb58ee878d1212c3ff4338a Mon Sep 17 00:00:00 2001
From: Shunsuke Shibayama <sbym1346@gmail.com>
Date: Mon, 28 Nov 2022 00:21:44 +0900
Subject: [PATCH] Fix #205

---
 compiler/erg_parser/ast.rs   |  4 ++++
 compiler/erg_parser/parse.rs | 26 ++++++++++++++++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/compiler/erg_parser/ast.rs b/compiler/erg_parser/ast.rs
index 9ce69515..2097ba8d 100644
--- a/compiler/erg_parser/ast.rs
+++ b/compiler/erg_parser/ast.rs
@@ -3450,6 +3450,10 @@ impl Expr {
         matches!(self, Expr::Accessor(acc) if acc.is_const())
     }
 
+    pub const fn is_definition(&self) -> bool {
+        matches!(self, Expr::Def(_) | Expr::ClassDef(_) | Expr::Methods(_))
+    }
+
     pub fn need_to_be_closed(&self) -> bool {
         matches!(
             self,
diff --git a/compiler/erg_parser/parse.rs b/compiler/erg_parser/parse.rs
index 978e2d33..76554143 100644
--- a/compiler/erg_parser/parse.rs
+++ b/compiler/erg_parser/parse.rs
@@ -298,8 +298,15 @@ impl Parser {
                 .try_reduce_chunk(true, false)
                 .map_err(|_| self.stack_dec())?;
             block.push(chunk);
-            self.level -= 1;
-            return Ok(block);
+            if block.last().unwrap().is_definition() {
+                let err = ParseError::simple_syntax_error(0, block.last().unwrap().loc());
+                self.level -= 1;
+                self.errs.push(err);
+                return Err(());
+            } else {
+                self.level -= 1;
+                return Ok(block);
+            }
         }
         if !self.cur_is(Newline) {
             let err = self.skip_and_throw_syntax_err("try_reduce_block");
@@ -362,6 +369,21 @@ impl Parser {
             self.level -= 1;
             self.errs.push(err);
             Err(())
+        } else if block.last().unwrap().is_definition() {
+            let err = ParseError::syntax_error(
+                line!() as usize,
+                block.last().unwrap().loc(),
+                switch_lang!(
+                    "japanese" => "ブロックの終端で変数を定義することは出来ません",
+                    "simplified_chinese" => "无法在块的末尾定义变量",
+                    "traditional_chinese" => "無法在塊的末尾定義變量",
+                    "english" => "cannot define a variable at the end of a block",
+                ),
+                None,
+            );
+            self.level -= 1;
+            self.errs.push(err);
+            Err(())
         } else {
             self.level -= 1;
             Ok(block)