main+parser: greatly improve error reporting

compiler/__main__.py

@@ -1,19 +1,35 @@
 from __future__ import annotations
 
+import sys
+
+from .logger import rootLogger, LogLevel
+from .parser import Parser, ParsingError
 from .tokenizer import Tokenizer, Tokens
 from .parser import Parser
 
 data = "2 * (32.9 + 1)"
 
 def main():
+    data = """
+    2 + 3 / (8 - 1 + 3) * 1
+      + 34.2
+    """
     tokenizer = Tokenizer()
-    tokens = tokenizer.tokenize("2 + 3")
+    tokens = tokenizer.tokenize(data)
 
     tokens = [token for token in tokens if token.kind not in [Tokens.Blank, Tokens.Newline]]
     print(tokens)
 
     parser = Parser(tokens)
-    parser.root()
+    try:
+        print(parser.parse())
+    except ParsingError as e:
+        e.location.source = data
+        print(f"{e}\n{e.location.show_in_source()}", file=sys.stderr)
+        if e.__cause__ is not None:
+            if rootLogger.level <= LogLevel.Debug:
+                raise e.__cause__
+            print(f"Caused by:\n{e.__cause__.__class__.__name__}: {e.__cause__}", file=sys.stderr)
 
 
 if __name__ == "__main__":

compiler/parser.py

@@ -103,5 +103,19 @@ class Parser:
         return summation
 
     def root(self):
-        self.expression()
-        self.expect(Tokens.EOF)
+        blocks = [
+            self.expression(),
+            self.expect(Tokens.EOF),
+        ]
+        return blocks
+
+    def parse(self) -> Node:
+        try:
+            return self.root()
+        except ParsingError:
+            raise
+        except Exception as e:
+            tok = self._last_accepted_token
+            if tok is None:
+                tok = self.token
+            raise ParsingError(tok.loc) from e