generate_alias_stub¶

generate_alias_stub(sym: AliasSymbol, ctx: StubContext) → str[source]¶

Re-emit a TypeVar, TypeAlias, NewType, ParamSpec, or TypeVarTuple declaration.

The source text is taken verbatim from the AST pre-pass (ast_info) so that constraints, bounds, and alias expansions are preserved exactly as written.

Emission format per kind is controlled by alias_style:

TypeAlias declarations (annotated, implicit bare, or PEP 695):

"compatible" (default) — Name: TypeAlias = <rhs> Works on all Python 3.10+ versions.
"pep695" — type Name = <rhs> Python 3.12+ only.
"auto" — uses pep695 when running on Python 3.12+, otherwise falls back to compatible.

TypeVar / ParamSpec / TypeVarTuple / NewType always emit as Name = Kind(...) regardless of alias_style.

Parameters:

sym (AliasSymbol) – The alias symbol from the SymbolTable.
ctx (StubContext) – The current StubContext.

Returns:

str – One declaration line, or "" when insufficient AST data is available.

Examples

>>> from stubpy.context import StubContext
>>> from stubpy.symbols import AliasSymbol
>>> from stubpy.ast_pass import TypeVarInfo
>>> tv = TypeVarInfo(name="T", lineno=1, kind="TypeVar", source_str="TypeVar('T')")
>>> sym = AliasSymbol("T", lineno=1, ast_info=tv)
>>> generate_alias_stub(sym, StubContext())
"T = TypeVar('T')"