Improved compiler error information

pytd12dk/compiler/compiler_types.py

@@ -66,4 +66,22 @@ class FileInfo:
 class CompilerError(Exception):
 
     def __init__(self, message: str, file_info: FileInfo):
-        super().__init__(message, file_info)
+        new_message = message
+        if file_info is not None:
+            new_message += (
+                f"\nIn file {file_info.filename} at line {file_info.line} "
+            )
+            if file_info.lines:
+                new_message += f"to line {file_info.line + file_info.lines}"
+                with open(file_info.filename, 'r') as file:
+                    new_message += ''.join(
+                        file.readlines()[
+                            file_info.line-1:file_info.line + file_info.lines])
+            else:
+                new_message += f"col {file_info.col}\n\n"
+                with open(file_info.filename, 'r') as file:
+                    new_message += file.readlines()[file_info.line-1]
+                new_message += ' ' * (
+                    file_info.col - 1) + '^' * file_info.length
+
+        super().__init__(new_message)

pytd12dk/compiler/main.py

@@ -4,17 +4,24 @@
 from typing import Sequence
 import argparse
 
+from .compiler_types import CompilerError
 from .lexer import lexer
 from .syntactical_analyzer import syntactical_analyzer
 
 def compile(args: argparse.Namespace):
-    tokens = lexer(args.input_file.read(), args.input_file.name)
+    try: tokens = lexer(args.input_file.read(), args.input_file.name)
+    except CompilerError as e:
+        print(type(e).__name__+':', e)
+        return
 
     if args.token_file:
         for token in tokens:
             args.token_file.write(str(token) + "\n")
 
-    syntax = syntactical_analyzer(tokens)
+    try: syntax = syntactical_analyzer(tokens)
+    except CompilerError as e:
+        print(type(e).__name__+':', e)
+        return
 
     if args.syntax_file:
         args.syntax_file.write(syntax.tree_str())