Expose warnings as pronto.warnings and improve warnings hierarchy

README.md

@@ -19,7 +19,7 @@
 
 ## 🚩 Table of Contents
 
-- [Overview](#-overview)
+- [Overview](#%EF%B8%8F-overview)
 - [Supported Languages](#%EF%B8%8F-supported-languages)
 - [Installing](#-installing)
 - [Examples](#-examples)

pronto/__init__.py

@@ -7,6 +7,7 @@
     .strip()
 )
 
+from .utils import warnings
 from .entity import Entity
 from .definition import Definition
 from .metadata import Metadata, Subset
@@ -18,6 +19,9 @@
 from .xref import Xref
 
 __all__ = [
+    # modules
+    warnings.__name__,
+    # classes
     Ontology.__name__,
     Entity.__name__,
     Term.__name__,

pronto/parsers/_fastobo.py

@@ -227,7 +227,9 @@ def add(src, dst=None, cb=None):
 
         def todo():
             return lambda c: warnings.warn(
-                f"cannot process `{c}`", NotImplementedWarning, stacklevel=3
+                f"cannot process `{c}`",
+                NotImplementedWarning,
+                stacklevel=3
             )
 
         _callbacks = {

pronto/utils/warnings.py

@@ -1,2 +1,26 @@
-class NotImplementedWarning(UserWarning):
+"""Warnings raised by the library.
+"""
+
+import warnings
+
+class ProntoWarning(Warning):
+    """The class for all warnings raised by `pronto`.
+    """
     pass
+
+class NotImplementedWarning(ProntoWarning, NotImplementedError):
+    """Some part of the code is yet to be implemented.
+    """
+    pass
+
+class UnstableWarning(ProntoWarning):
+    """The behaviour of the executed code might change in the future.
+    """
+    pass
+
+class SyntaxWarning(ProntoWarning, SyntaxError):
+    """The parsed document contains incomplete or unsound constructs.
+    """
+    def __init__(self, *args, **kwargs):
+        ProntoWarning.__init__(self, *args, **kwargs)
+        SyntaxError.__init__(self, *args, **kwargs)