errors: use termcolor for terminal output coloring + enable raising non-fatal errors

compiler/errors.py

@@ -1,29 +1,57 @@
 from __future__ import annotations
 
+import enum
 import inspect
 import sys
+from typing import TextIO
+
+from termcolor import termcolor
 
 from . import source, lexer
 
 
+class LevelType:
+
+    def __init__(self, name: str, color: termcolor.Color = None):
+        """
+
+        :param name:
+        :param color: ANSI style color escapes without the prefix nor the suffix
+        """
+        self.name = name
+        self.color = color
+
+    def __str__(self) -> str:
+        return self.show_with_suffix()
+
+    def show_with_suffix(self, suffix=":") -> str:
+        return termcolor.colored(f"{self.name}{suffix}", color=self.color, attrs=["bold"])
+
+
+class Levels(enum.Enum):
+    Warning = LevelType("warning", color="light_yellow")
+    Error = LevelType("error", color="red")
+
+
 class CompilationError(Exception):
     def __init__(self, location: source.SourceLocation, message: str = "Unknown error"):
-        super().__init__(f"{str(location)}: \033[1merror:\033[0m {message}")
+        super().__init__(f"{str(location)}: {Levels.Error.value.show_with_suffix(':')} {message}")
         self.location = location
 
 
 class CompilationWarning(Warning):
     _pending_warnings: list[CompilationWarning] = []
 
-    def __init__(self, location: source.SourceLocation, message: str = "Unknown warning"):
-        super().__init__(f"{str(location)}: \033[1mwarning:\033[0m {message}")
+    def __init__(self, location: source.SourceLocation, message: str = "Unknown warning",
+                 level: Levels = Levels.Warning):
+        super().__init__(f"{str(location)}: {level.value.show_with_suffix(':')} {message}")
         self.location = location
 
     @classmethod
-    def show_warnings(cls, _source: str):
+    def show_warnings(cls, _source: str, file: TextIO = sys.stderr):
         for warning in CompilationWarning._pending_warnings:
             warning.location.source = _source
-            print(f"{warning}\n{warning.location.show_in_source()}", file=sys.stderr)
+            print(f"{warning}\n{warning.location.show_in_source()}", file=file)
 
     def raise_warning(self):
         CompilationWarning._pending_warnings += [self]