Coerce maps - Coercion

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# Coerce maps

class sage.structure.coerce_maps.CCallableConvertMap_class

  Bases: `Map`

class sage.structure.coerce_maps.CallableConvertMap

  Bases: `Map`

  This lets one easily create maps from any callable object.

  This is especially useful to create maps from bound methods.

  EXAMPLES:

  Sage

      sage: from sage.structure.coerce_maps import CallableConvertMap
      sage: def foo(P, x): return x/2
      sage: f = CallableConvertMap(ZZ, QQ, foo)
      sage: f(3)
      3/2
      sage: f
      Conversion via foo map:
        From: Integer Ring
        To:   Rational Field

  Python

      >>> from sage.all import *
      >>> from sage.structure.coerce_maps import CallableConvertMap
      >>> def foo(P, x): return x/Integer(2)
      >>> f = CallableConvertMap(ZZ, QQ, foo)
      >>> f(Integer(3))
      3/2
      >>> f
      Conversion via foo map:
        From: Integer Ring
        To:   Rational Field

  Create a homomorphism from \(\RR\) to \(\RR^+\) viewed as additive groups.

  Sage

      sage: # needs sage.symbolic
      sage: f = CallableConvertMap(RR, RR, exp, parent_as_first_arg=False)
      sage: f(0)
      1.00000000000000
      sage: f(1)
      2.71828182845905
      sage: f(-3)
      0.0497870683678639

  [Python]

      >>> from sage.all import *
      >>> # needs sage.symbolic
      >>> f = CallableConvertMap(RR, RR, exp, parent_as_first_arg=False)
      >>> f(Integer(0))
      1.00000000000000
      >>> f(Integer(1))
      2.71828182845905
      >>> f(-Integer(3))
      0.0497870683678639

class sage.structure.coerce_maps.DefaultConvertMap_unique

  Bases: `Map`

  This morphism simply defers action to the codomain’s element_constructor method, WITHOUT passing in the codomain as the first argument.

  This is used for creating elements that don’t take a parent as the first argument to their __init__ method, for example, Integers, Rationals, Algebraic Reals… all have a unique parent. It is also used when the element_constructor is a bound method (whose self argument is assumed to be bound to the codomain).

class sage.structure.coerce_maps.ListMorphism

  Bases: `Map`

class sage.structure.coerce_maps.NamedConvertMap

  Bases: `Map`

  This is used for creating elements via the _xxx_ methods.

  For example, many elements implement an _integer_ method to convert to ZZ, or a _rational_ method to convert to QQ.

  method_name

class sage.structure.coerce_maps.TryMap

  Bases: `Map`

sage.structure.coerce_maps.test_CCallableConvertMap(domain, name=None)

  For testing CCallableConvertMap_class.