Refactor message.Answer class in a way, that it can be constructed dynamically step by step, in preparation of using streaming API.

chatmastermind/commands/question.py

@@ -101,7 +101,7 @@ def create_message(chat: ChatDB, args: argparse.Namespace) -> Message:
         if code_file is not None and len(code_file) > 0:
             add_file_as_code(question_parts, code_file)
 
-    full_question = '\n\n'.join(question_parts)
+    full_question = '\n\n'.join([str(s) for s in question_parts])
 
     message = Message(question=Question(full_question),
                       tags=args.output_tags,

chatmastermind/message.py

@@ -5,7 +5,9 @@ import pathlib
 import yaml
 import tempfile
 import shutil
+import io
 from typing import Type, TypeVar, ClassVar, Optional, Any, Union, Final, Literal, Iterable, Tuple
+from typing import Generator, Iterator
 from typing import get_args as typing_get_args
 from dataclasses import dataclass, asdict, field
 from .tags import Tag, TagLine, TagError, match_tags, rename_tags
@@ -142,30 +144,100 @@ class Answer(str):
     txt_header: ClassVar[str] = '==== ANSWER ===='
     yaml_key: ClassVar[str] = 'answer'
 
-    def __new__(cls: Type[AnswerInst], string: str) -> AnswerInst:
+    def __init__(self, data: Union[str, Generator[str, None, None]]) -> None:
+        # Indicator of whether all of data has been processed
+        self.is_exhausted: bool = False
+
+        # Initialize data
+        self.iterator: Iterator[str] = self._init_data(data)
+
+        # Set up the buffer to hold the 'Answer' content
+        self.buffer: io.StringIO = io.StringIO()
+
+    def _init_data(self, data: Union[str, Generator[str, None, None]]) -> Iterator[str]:
         """
-        Make sure the answer string does not contain the header as a whole line.
+        Process input data (either a string or a string generator)
         """
-        if cls.txt_header in string.split('\n'):
-            raise MessageError(f"Answer '{string}' contains the header '{cls.txt_header}'")
-        instance = super().__new__(cls, string)
-        return instance
+        if isinstance(data, str):
+            yield data
+        else:
+            yield from data
+
+    def __str__(self) -> str:
+        """
+        Output all content when converted into a string
+        """
+        # Ensure all data has been processed
+        for _ in self:
+            pass
+        # Return the 'Answer' content
+        return self.buffer.getvalue()
+
+    def __repr__(self) -> str:
+        return repr(str(self))
+
+    def __iter__(self) -> Generator[str, None, None]:
+        """
+        Allows the object to be iterable
+        """
+        # Generate content if not all data has been processed
+        if not self.is_exhausted:
+            yield from self.generator_iter()
+        else:
+            yield self.buffer.getvalue()
+
+    def generator_iter(self) -> Generator[str, None, None]:
+        """
+        Main generator method to process data
+        """
+        for piece in self.iterator:
+            # Write to buffer and yield piece for the iterator
+            self.buffer.write(piece)
+            yield piece
+        self.is_exhausted = True  # Set the flag that all data has been processed
+        # If the header occurs in the 'Answer' content, raise an error
+        if f'\n{self.txt_header}' in self.buffer.getvalue() or self.buffer.getvalue().startswith(self.txt_header):
+            raise MessageError(f"Answer {repr(self.buffer.getvalue())} contains the header {repr(Answer.txt_header)}")
+
+    def __eq__(self, other: object) -> bool:
+        """
+        Comparing the object to a string or another object
+        """
+        if isinstance(other, str):
+            return str(self) == other  # Compare the string value of this object to the other string
+        # Default behavior for comparing non-string objects
+        return super().__eq__(other)
+
+    def __hash__(self) -> int:
+        """
+        Generate a hash for the object based on its string representation.
+        """
+        return hash(str(self))
+
+    def __format__(self, format_spec: str) -> str:
+        """
+        Return a formatted version of the string as per the format specification.
+        """
+        return str(self).__format__(format_spec)
 
     @classmethod
     def from_list(cls: Type[AnswerInst], strings: list[str]) -> AnswerInst:
         """
-        Build Question from a list of strings. Make sure strings do not contain the header.
+        Build Answer from a list of strings. Make sure strings do not contain the header.
         """
-        if cls.txt_header in strings:
-            raise MessageError(f"Question contains the header '{cls.txt_header}'")
-        instance = super().__new__(cls, '\n'.join(strings).strip())
-        return instance
+        def _gen() -> Generator[str, None, None]:
+            if len(strings) > 0:
+                yield strings[0]
+                for s in strings[1:]:
+                    yield '\n'
+                    yield s
+        return cls(_gen())
 
     def source_code(self, include_delims: bool = False) -> list[str]:
         """
         Extract and return all source code sections.
         """
-        return source_code(self, include_delims)
+        return source_code(str(self), include_delims)
 
 
 class Question(str):
@@ -441,7 +513,7 @@ class Message():
         output.append(self.question)
         if self.answer:
             output.append(Answer.txt_header)
-            output.append(self.answer)
+            output.append(str(self.answer))
         return '\n'.join(output)
 
     def to_file(self, file_path: Optional[pathlib.Path]=None, mformat: MessageFormat = message_default_format) -> None:  # noqa: 11
@@ -491,7 +563,7 @@ class Message():
                 temp_fd.write(f'{ModelLine.from_model(self.model)}\n')
             temp_fd.write(f'{Question.txt_header}\n{self.question}\n')
             if self.answer:
-                temp_fd.write(f'{Answer.txt_header}\n{self.answer}\n')
+                temp_fd.write(f'{Answer.txt_header}\n{str(self.answer)}\n')
         shutil.move(temp_file_path, file_path)
 
     def __to_file_yaml(self, file_path: pathlib.Path) -> None:
@@ -560,7 +632,7 @@ class Message():
            or (mfilter.ai and (not self.ai or mfilter.ai != self.ai))  # noqa: W503
            or (mfilter.model and (not self.model or mfilter.model != self.model))  # noqa: W503
            or (mfilter.question_contains and mfilter.question_contains not in self.question)  # noqa: W503
-           or (mfilter.answer_contains and (not self.answer or mfilter.answer_contains not in self.answer))  # noqa: W503
+           or (mfilter.answer_contains and (not self.answer or mfilter.answer_contains not in str(self.answer)))  # noqa: W503
            or (mfilter.answer_state == 'available' and not self.answer)  # noqa: W503
            or (mfilter.ai_state == 'available' and not self.ai)  # noqa: W503
            or (mfilter.model_state == 'available' and not self.model)  # noqa: W503

tests/test_message.py

@@ -91,7 +91,7 @@ class QuestionTestCase(unittest.TestCase):
 class AnswerTestCase(unittest.TestCase):
     def test_answer_with_header(self) -> None:
         with self.assertRaises(MessageError):
-            Answer(f"{Answer.txt_header}\nno")
+            str(Answer(f"{Answer.txt_header}\nno"))
 
     def test_answer_with_legal_header(self) -> None:
         answer = Answer(f"This is a line contaning '{Answer.txt_header}'\nIt is what it is.")