CXXR (C++ R)
Classes | Namespaces | Macros | Functions | Variables
Environment.h File Reference

($Id: Environment.h 1390 2013-06-11 14:41:41Z arr $)

Class CXXR::Environment and associated C interface. More...

#include "CXXR/RObject.h"
#include <boost/serialization/access.hpp>
#include <boost/serialization/base_object.hpp>
#include <boost/serialization/nvp.hpp>
#include "CXXR/Frame.hpp"
#include "CXXR/GCStackRoot.hpp"
#include "CXXR/Symbol.h"
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Classes

class  CXXR::Environment
 Mapping from Symbols to R objects. More...
class  CXXR::Environment::LoopScope
 Object authorising R 'break' and 'next' commands. More...
class  CXXR::Environment::ReturnScope
 Object authorising R 'return' command. More...

Namespaces

namespace  CXXR
 Namespace for the CXXR project.

Macros

#define DETACH_LOCAL_FRAMES

Functions

pair< Environment
*, FunctionBase * > 
CXXR::findFunction (const Symbol *symbol, Environment *env, bool inherits=true)
 Search for a Binding of a Symbol to a FunctionBase.
template<typename UnaryPredicate >
std::pair< Environment
*, RObject * > 
CXXR::findTestedValue (const Symbol *symbol, Environment *env, UnaryPredicate pred, bool inherits)
 Search for a Binding whose value satisfies a predicate.
template<class Archive >
void boost::serialization::load_construct_data (Archive &ar, CXXR::Environment *t, const unsigned int version)
 Template specialisation.
Rboolean Rf_isEnvironment (SEXP s)
 Is this a CXXR::Environment?
SEXP ENCLOS (SEXP x)
 Access enclosing environment.
Rboolean ENV_DEBUG (SEXP x)
 Should the debugger single-step?
SEXP FRAME (SEXP x)
 Access an environment's Frame, represented as a PairList.
void SET_ENV_DEBUG (SEXP x, Rboolean v)
 Enable/disable single-stepping of the debugger.
void SET_SYMVALUE (SEXP x, SEXP val)
 Set symbol's value in the base environment.
SEXP SYMVALUE (SEXP x)
 Symbol's value in the base environment.

Variables

SEXP R_EmptyEnv
SEXP R_BaseEnv
SEXP R_GlobalEnv
SEXP R_BaseNamespace

Detailed Description

Class CXXR::Environment and associated C interface.


Macro Definition Documentation

#define DETACH_LOCAL_FRAMES

If the preprocessor variable DETACH_LOCAL_FRAMES is defined, then code is inserted which keeps track of whether the local Environment of a Closure application may continue to be reachable after the Closure application returns. If not, then just before the Closure application returns, the Environment is detached from its Frame. This breaks possible loops in the GCNode/GCEdge graph, thus enabling the Environment to be garbage-collected immediately.

Unfortunately, enabling this extra code slows CXXR down very slightly; however, it may prove beneficial in the future when combined with provenance tracking.


Function Documentation

SEXP ENCLOS ( SEXP  x)
inline

Access enclosing environment.

Parameters:
xPointer to a CXXR::Environment (checked).
Returns:
Pointer to the enclosing environment of x .
Rboolean ENV_DEBUG ( SEXP  x)
inline

Should the debugger single-step?

Parameters:
xPointer to a CXXR::Environment object (checked).
Returns:
true if single-stepping is set, i.e. the debugger should single-step within this environment.
SEXP FRAME ( SEXP  x)
inline

Access an environment's Frame, represented as a PairList.

Parameters:
xPointer to a CXXR::Environment (checked).
Returns:
Pointer to a PairList representing the contents of the Frame of x (may be null). This PairList is generated on the fly, so this is a relatively expensive operation. Alterations to the returned PairList will not alter the Environment's Frame.
Note:
Beware that since (unlike CR) this isn't a simple accessor function, its return value will need protection from garbage collection.
Rboolean Rf_isEnvironment ( SEXP  s)
inline

Is this a CXXR::Environment?

Parameters:
sPointer to an RObject.
Returns:
TRUE iff the RObject pointed to by s is an environment.
void SET_ENV_DEBUG ( SEXP  x,
Rboolean  v 
)
inline

Enable/disable single-stepping of the debugger.

Parameters:
xPointer a CXXR::Environment object (checked).
vThe new single-stepping state (true = enabled).
void SET_SYMVALUE ( SEXP  x,
SEXP  val 
)
inline

Set symbol's value in the base environment.

Parameters:
xPointer to a CXXR::Symbol (checked).
valPointer to the RObject now to be considered as the value of this symbol. A null pointer or R_UnboundValue are permissible values of val.
Todo:
No binding to R_UnboundValue ought to be created.
SEXP SYMVALUE ( SEXP  x)
inline

Symbol's value in the base environment.

Parameters:
xPointer to a CXXR::Symbol (checked).
Returns:
Pointer to a CXXR::RObject representings x's value. Returns R_UnboundValue if no value is currently associated with the Symbol.