titus.signature.Lifespan¶

class titus.signature.Lifespan(birth, deprecation, death, contingency)[source]¶

Bases: object

Describes the range of support of a function signature (or, in the future, special form) in terms of an optional beginning of life (birth), and optional deprecation and end of life (death).

If a deprecation is specified, a death must be as well, and vice-versa. Whether or not a birth is specified is independent.

At a given titus.signature.PFAVersion, the Lifespan has three possible states: current (method current returns True), deprecated (method deprecated returns True), and non-existent (both current and deprecated return False). Method current and deprecated are mutually exclusive; for a given titus.signature.PFAVersion, they would never both return True.

__init__(birth, deprecation, death, contingency)¶

Create a Lifespan from a birth, deprecation, death, and contingency.

Parameters:

birth (titus.signature.PFAVersion or None) – first PFA version number in which this signature (or special form) is valid; None means the beginning of time deprecation (titus.signature.PFAVersion or None) – first PFA version number in which this signature should raise a deprecation warning; None means never death (titus.signature.PFAVersion or None) – first PFA version number in which this signature is skipped over as not existing; None means the end of time contingency (string or None) – message to accompany the deprecation warning; usually tells the user which function to use instead

current(now)¶

Parameters:	now (titus.signature.PFAVersion) – the version number to query
Return type:	bool
Returns:	True if the feature exists and is not deprecated in version now, False otherwise.

deprecated(now)¶

Parameters:	now (titus.signature.PFAVersion) – the version number to query
Return type:	bool
Returns:	True if the feature exists and is deprecated in version now, False otherwise.