typeInfo

typeInfo<-

the function whose type information is to be accessed

func

a logical value. This controls whether the body of the
    function <code>func</code> is rewritten so that checks for the arguments
    and return type are added to the code and the appropriate
    actions are taken when the function returns control to the caller.
    This is necessary to get calls to <code>return</code> in the function
    to behave correctly and allow the return value to be validated.
  

rewrite

an object of class <code><a rd-options="" href="/link/TypeSpecification-class?package=TypeInfo&version=1.38.0" data-mini-rdoc="TypeInfo::TypeSpecification-class">TypeSpecification-class</a></code>

value


  These functions provide controlled access to type information
  for a function.
  They encapsulate the way the information is stored for the function
  (although it is trivial to find out how it is done and where the
  information is)


programming

interface

A prototype for a mechanism for specifying the types of
parameters and the return value for an R function. This is
meta-information that can be used to generate stubs for servers
and various interfaces to these functions. Additionally, the
arguments in a call to a typed function can be validated using
the type specifications.
We allow types to be specified as either
i) by class name using either inheritance -  is(x, className),
or strict instance of - class(x) %in% className, or
ii) a dynamic test given as an R expression which is evaluated
at run-time.
More precise information and interesting tests can be done via
ii), but it is harder to use this information as meta-data as
it requires more effort to interpret it and it is of course
run-time information. It is typically more meaningful.

Duncan Lang

TypeInfo

Optional Type Specification Prototype

typeInfo function

a logical value. This controls whether the body of the
    function <code>func</code> is rewritten so that checks for the arguments
    and return type are added to the code and the appropriate
    actions are taken when the function returns control to the caller.
    This is necessary to get calls to <code>return</code> in the function
    to behave correctly and allow the return value to be validated.

an object of class <code><a href="TypeSpecification-class" rd-options="">TypeSpecification-class</a></code>

These functions provide controlled access to type information
  for a function.
  They encapsulate the way the information is stored for the function
  (although it is trivial to find out how it is done and where the
  information is)

typeInfo: Get or set type information for a function.

Description

Usage

Arguments

Value

References

See Also