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[patch] Defer Python annotations so a class can name itself or a later class - #158
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…r class Python before 3.14 evaluates an annotation when the def or class body runs, so a factory returning its own class, a parameter of the declaring type, a field holding one, or a parameter naming a class declared further down made the generated module raise NameError on import. The Python generator now writes `from __future__ import annotations` as the file's first statement. Fixes #102 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01GQx1vbckMdZECPqnBTXWek
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Fixes #102
What was wrong
Python before 3.14 evaluates annotations eagerly. A generated class whose own name, or the name of a class declared later in the file, appeared in a return type, parameter or field annotation therefore made the module raise
NameErroron import. #64 fixed the same problem for base lists only.Change
PythonGeneratornow overridesWriteFileDirectivesand writesfrom __future__ import annotationsas the first statement of a generatedSourceFile. It goes after the header comment and before any import. A file with no members gets nothing.PythonBaseFromGenericType), because a base is an expression and the future import does not defer it.WriteFileDirectivesremark inLanguageGeneratorBase, which said C++ was the only override even though Go already overrides it too.Tests
New
PythonGeneratedSourceImportsTests.AnnotationsNamingUndeclaredClasses_Importgenerates a module containing:It then imports the module with a real interpreter and calls the factory.
Before the fix it failed under Python 3.11 with
NameError: name 'Point' is not defined. With the fix it passes.Full suite: 1055/1055 passed locally.
🤖 Generated with Claude Code
https://claude.ai/code/session_01GQx1vbckMdZECPqnBTXWek
Generated by Claude Code