From 5b3f0262a77cac70de2c4a35a80fd789081a3641 Mon Sep 17 00:00:00 2001
From: Antoine Viallon <antoine@lesviallon.fr>
Date: Mon, 8 May 2023 20:30:51 +0200
Subject: [PATCH] parser: add UnexpectedTokenError

---
 compiler/parser.py | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/compiler/parser.py b/compiler/parser.py
index 13e2ed5..8228751 100644
--- a/compiler/parser.py
+++ b/compiler/parser.py
@@ -16,6 +16,14 @@ class ParsingError(Exception):
         self.location = location
 
 
+class UnexpectedTokenError(ParsingError):
+    def __init__(self, got: Token, wanted: Tokens | str):
+        message = wanted
+        if type(wanted) == Tokens:
+            message = str(wanted)
+        super().__init__(got.loc, f"Unexpected token '{got}', wanted {message}")
+
+
 class Parser:
     def __init__(self, tokens: List[Token]):
         self.tokens = tokens
@@ -54,7 +62,7 @@ class Parser:
         r = self.accept(token_type)
         logger.debug(f"Expecting {token_type}, got {r}")
         if r is False:
-            raise ParsingError(self.token.loc, f"Unexpected token '{self.token}', wanted {token_type}")
+            raise UnexpectedTokenError(self.token, token_type)
         return r
 
     def number(self, mandatory: bool = False):
@@ -65,7 +73,7 @@ class Parser:
             logger.debug(f"Found integer {tok}")
             return Integer(value=int(tok.value))
         elif mandatory:
-            raise ParsingError(self.token.loc, f"Unexpected token '{self.token}', wanted integer or float")
+            raise UnexpectedTokenError(self.token, "integer or float")
 
     def binary_op(self, operand_func: Callable[[], Value], operators: Dict[Tokens, Value]):
         operand = operand_func()
@@ -86,8 +94,7 @@ class Parser:
         elif num := self.number():
             return num
         else:
-            raise ParsingError(self.token.loc, f"Unexpected token '{self.token}', wanted parenthesized expression or "
-                                               f"number")
+            raise UnexpectedTokenError(self.token, "parenthesized expression or number")
 
     def term(self) -> Value:
         return self.binary_op(self.factor, operators={