From 72185fecd54d9215dc4ff8fc5a1838a83d0f941d Mon Sep 17 00:00:00 2001
From: harupy <hkawamura0130@gmail.com>
Date: Wed, 4 Jan 2023 13:16:03 +0900
Subject: [PATCH] Add with_col_offset and with_row_offset to Location

---
 codegen/src/symboltable.rs  |  2 +-
 core/src/location.rs        | 40 +++++++++++++++++++++++++++++++++++++
 parser/src/error.rs         |  2 +-
 parser/src/string_parser.rs |  8 ++------
 4 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/codegen/src/symboltable.rs b/codegen/src/symboltable.rs
index 3182f3d..a12ad5f 100644
--- a/codegen/src/symboltable.rs
+++ b/codegen/src/symboltable.rs
@@ -168,7 +168,7 @@ impl SymbolTableError {
     pub fn into_codegen_error(self, source_path: String) -> CodegenError {
         CodegenError {
             error: CodegenErrorType::SyntaxError(self.error),
-            location: Location::new(self.location.row(), self.location.column() + 1),
+            location: self.location.with_col_offset(1),
             source_path,
         }
     }
diff --git a/core/src/location.rs b/core/src/location.rs
index 7f1adc4..b7b2c8b 100644
--- a/core/src/location.rs
+++ b/core/src/location.rs
@@ -58,6 +58,34 @@ impl Location {
         self.row += 1;
         self.column = 0;
     }
+
+    pub fn with_col_offset<T: TryInto<isize>>(&self, offset: T) -> Self
+    where
+        <T as TryInto<isize>>::Error: std::fmt::Debug,
+    {
+        let column = (self.column as isize
+            + offset
+                .try_into()
+                .expect("offset should be able to convert to isize")) as u32;
+        Location {
+            row: self.row,
+            column,
+        }
+    }
+
+    pub fn with_row_offset<T: TryInto<isize>>(&self, offset: T) -> Self
+    where
+        <T as TryInto<isize>>::Error: std::fmt::Debug,
+    {
+        let row = (self.row as isize
+            + offset
+                .try_into()
+                .expect("offset should be able to convert to isize")) as u32;
+        Location {
+            row,
+            column: self.column,
+        }
+    }
 }
 
 #[cfg(test)]
@@ -77,4 +105,16 @@ mod tests {
         assert!(Location::new(1, 1) < Location::new(2, 1));
         assert!(Location::new(1, 2) < Location::new(2, 1));
     }
+
+    #[test]
+    fn test_with_col_offset() {
+        assert_eq!(Location::new(1, 1).with_col_offset(1), Location::new(1, 2));
+        assert_eq!(Location::new(1, 1).with_col_offset(-1), Location::new(1, 0));
+    }
+
+    #[test]
+    fn test_with_row_offset() {
+        assert_eq!(Location::new(1, 1).with_row_offset(1), Location::new(2, 1));
+        assert_eq!(Location::new(1, 1).with_row_offset(-1), Location::new(0, 1));
+    }
 }
diff --git a/parser/src/error.rs b/parser/src/error.rs
index 7a4f60b..6df758b 100644
--- a/parser/src/error.rs
+++ b/parser/src/error.rs
@@ -213,7 +213,7 @@ pub(crate) fn parse_error_from_lalrpop(
             let expected = (expected.len() == 1).then(|| expected[0].clone());
             ParseError {
                 error: ParseErrorType::UnrecognizedToken(token.1, expected),
-                location: Location::new(token.0.row(), token.0.column() + 1),
+                location: token.0.with_col_offset(1),
                 source_path,
             }
         }
diff --git a/parser/src/string_parser.rs b/parser/src/string_parser.rs
index b305493..52818bf 100644
--- a/parser/src/string_parser.rs
+++ b/parser/src/string_parser.rs
@@ -32,7 +32,7 @@ impl<'a> StringParser<'a> {
             kind,
             str_start,
             str_end,
-            location: Location::new(str_start.row(), str_start.column() + offset),
+            location: str_start.with_col_offset(offset),
         }
     }
 
@@ -523,11 +523,7 @@ impl<'a> StringParser<'a> {
 
 fn parse_fstring_expr(source: &str, location: Location) -> Result<Expr, ParseError> {
     let fstring_body = format!("({source})");
-    parse_expression_located(
-        &fstring_body,
-        "<fstring>",
-        Location::new(location.row(), location.column() - 1),
-    )
+    parse_expression_located(&fstring_body, "<fstring>", location.with_col_offset(-1))
 }
 
 pub fn parse_string(