AbstractQoreNode Class Reference

The base class for all value and parse types in Qore expression trees. More...

#include <AbstractQoreNode.h>

Inheritance diagram for AbstractQoreNode:

QoreReferenceCounter AbstractCallReferenceNode QoreHashNode QoreListNode QoreObject SimpleQoreNode ResolvedCallReferenceNode SimpleValueQoreNode BinaryNode DateTimeNode QoreBigIntNode QoreFloatNode QoreStringNode ReferenceNode UniqueValueQoreNode QoreBoolNode QoreNothingNode QoreNullNode QoreBoolFalseNode QoreBoolTrueNode

List of all members.

Public Member Functions

DLLEXPORT AbstractQoreNode (qore_type_t t, bool n_value, bool n_needs_eval, bool n_there_can_be_only_one=false, bool n_custom_reference_handlers=false)
 constructor takes the type
DLLEXPORT bool getAsBool () const
 returns the boolean value of the object
DLLEXPORT int getAsInt () const
 returns the integer value of the object
DLLEXPORT int64 getAsBigInt () const
 returns the 64-bit integer value of the object
DLLEXPORT double getAsFloat () const
 returns the float value of the object
virtual DLLEXPORT QoreStringgetStringRepresentation (bool &del) const
 returns the value of the type converted to a string, default implementation: returns the empty string
virtual DLLEXPORT void getStringRepresentation (QoreString &str) const
 concatentates the value of the type to an existing QoreString reference, default implementation does nothing
virtual DLLEXPORT class DateTimegetDateTimeRepresentation (bool &del) const
 returns the DateTime representation of this type (default implementation: returns ZeroDate, del = false)
virtual DLLEXPORT void getDateTimeRepresentation (DateTime &dt) const
 assigns the date representation of a value to the DateTime reference passed, default implementation does nothing
virtual DLLEXPORT int getAsString (QoreString &str, int foff, ExceptionSink *xsink) const =0
 concatenate the verbose string representation of the value (including all contained values for container types) to an existing QoreString
virtual DLLEXPORT QoreStringgetAsString (bool &del, int foff, ExceptionSink *xsink) const =0
 returns a QoreString giving the verbose string representation of the value (including all contained values for container types)
DLLLOCAL bool needs_eval () const
 returns true if the object needs evaluation to return a value, false if not
virtual DLLEXPORT
AbstractQoreNode
realCopy () const =0
 returns a copy of the object; the caller owns the reference count
virtual DLLEXPORT bool is_equal_soft (const AbstractQoreNode *v, ExceptionSink *xsink) const =0
 tests for equality ("deep compare" including all contained values for container types) with possible type conversion (soft compare)
virtual DLLEXPORT bool is_equal_hard (const AbstractQoreNode *v, ExceptionSink *xsink) const =0
 tests for equality ("deep compare" including all contained values for container types) without type conversions (hard compare)
DLLLOCAL qore_type_t getType () const
 returns the data type
virtual DLLEXPORT const char * getTypeName () const =0
 returns the type name as a c string
virtual DLLEXPORT
AbstractQoreNode
parseInit (LocalVar *oflag, int pflag, int &lvids)
 for use by parse types to initialize them for execution during stage 1 parsing
DLLEXPORT AbstractQoreNodeeval (ExceptionSink *xsink) const
 evaluates the object and returns a value (or 0)
DLLEXPORT AbstractQoreNodeeval (bool &needs_deref, ExceptionSink *xsink) const
 optionally evaluates the argument
DLLEXPORT int64 bigIntEval (ExceptionSink *xsink) const
 evaluates the object and returns a 64-bit integer value
DLLEXPORT int integerEval (ExceptionSink *xsink) const
 evaluates the object and returns an integer value
DLLEXPORT bool boolEval (ExceptionSink *xsink) const
 evaluates the object and returns a boolean value
DLLEXPORT double floatEval (ExceptionSink *xsink) const
 evaluates the object and returns a floating-point value
DLLLOCAL bool is_value () const
 returns true if the node represents a value
DLLEXPORT void deref (ExceptionSink *xsink)
 decrements the reference count and calls derefImpl() if there_can_be_only_one is false, otherwise does nothing
DLLEXPORT AbstractQoreNoderefSelf () const
 returns "this" with an incremented reference count
DLLEXPORT void ref () const
 increments the reference count
DLLEXPORT bool isReferenceCounted () const
 returns true if the object is reference-counted

Protected Member Functions

virtual DLLEXPORT ~AbstractQoreNode ()
 default destructor does nothing

Protected Attributes

qore_type_t type: 11
 the type of the object
bool value: 1
 this is true for values, if false then either the type needs evaluation to produce a value or is a parse expression
bool needs_eval_flag: 1
 if this is true then the type can be evaluated
bool there_can_be_only_one: 1
 if this is set to true, then reference counting is turned off for objects of this class
bool custom_reference_handlers: 1
 set to one for objects that need custom reference handlers


Detailed Description

The base class for all value and parse types in Qore expression trees.

Defines the interface for all value and parse types in Qore expression trees. Default implementations are given for most virtual functions.


Constructor & Destructor Documentation

virtual DLLEXPORT AbstractQoreNode::~AbstractQoreNode (  )  [protected, virtual]

default destructor does nothing

The destructor is protected because it should not be called directly, which also means that these objects cannot normally be created on the stack. They are referenced counted, and the deref() function should be used to decrement the reference count rather than using the delete operator. Because the QoreObject class at least could throw a Qore Exception when it is deleted, AbstractQoreNode::deref() takes an ExceptionSink pointer argument by default as well.

DLLEXPORT AbstractQoreNode::AbstractQoreNode ( qore_type_t  t,
bool  n_value,
bool  n_needs_eval,
bool  n_there_can_be_only_one = false,
bool  n_custom_reference_handlers = false 
)

constructor takes the type

The type code for the class is passed as the argument to the constructor

Parameters:
t the Qore type code identifying this class in the Qore type system
n_value determines if this is a value type or not
n_needs_eval determines if the type needs evaluation when AbstractQoreNode::eval() is called
n_there_can_be_only_one whereas this type is normally reference counted, if this is set to true, then referencing counting is turned off for this type. This can only be turned on when the type represents a single value.
n_custom_reference_handlers if true then the class implements its own reference handlers


Member Function Documentation

DLLEXPORT int64 AbstractQoreNode::bigIntEval ( ExceptionSink xsink  )  const

evaluates the object and returns a 64-bit integer value

if needs_eval() returns true, then returns bigIntEvalImpl() otherwise returns getAsBigInt()

Parameters:
xsink if an error occurs, the Qore-language exception information will be added here
Returns:
the result of the evaluation of the object

DLLEXPORT bool AbstractQoreNode::boolEval ( ExceptionSink xsink  )  const

evaluates the object and returns a boolean value

if needs_eval() returns true, then returns boolEvalImpl() otherwise returns getAsBool()

Parameters:
xsink if an error occurs, the Qore-language exception information will be added here
Returns:
the result of the evaluation of the object

DLLEXPORT void AbstractQoreNode::deref ( ExceptionSink xsink  ) 

decrements the reference count and calls derefImpl() if there_can_be_only_one is false, otherwise does nothing

if there_can_be_only_one is false, calls derefImpl() and deletes the object when the reference count = 0. The ExceptionSink argument is needed for those types that could throw an exception when they are deleted (ex: QoreObject)

Parameters:
xsink if an error occurs, the Qore-language exception information will be added here

Referenced by discard().

DLLEXPORT AbstractQoreNode* AbstractQoreNode::eval ( bool &  needs_deref,
ExceptionSink xsink 
) const

optionally evaluates the argument

return value requires a deref(xsink) if needs_deref is true if needs_eval() is true, needs_deref = true, returns evalImpl() otherwise needs_deref = false returns "this" NOTE: do not use this function directly, use the QoreNodeEvalOptionalRefHolder class instead

Parameters:
needs_deref this is an output parameter, if needs_deref is true then the value returned must be dereferenced
xsink if an error occurs, the Qore-language exception information will be added here
See also:
QoreNodeEvalOptionalRefHolder

DLLEXPORT AbstractQoreNode* AbstractQoreNode::eval ( ExceptionSink xsink  )  const

evaluates the object and returns a value (or 0)

return value requires a deref(xsink) (if not 0). If needs_eval() returns false, then this function just returns refSelf(). Otherwise evalImpl() is returned.

          ReferenceHolder<AbstractQoreNode> value(n->eval(xsink));
          if (!value) // note that if a qore-language exception occured, then value = 0
             return 0;
          ...
          return value.release();
Parameters:
xsink if an error occurs, the Qore-language exception information will be added here
Returns:
the result of the evaluation, if non-0, must be dereferenced manually
See also:
ReferenceHolder

Referenced by QoreNodeEvalOptionalRefHolder::QoreNodeEvalOptionalRefHolder().

DLLEXPORT double AbstractQoreNode::floatEval ( ExceptionSink xsink  )  const

evaluates the object and returns a floating-point value

if needs_eval() returns true, then returns floatEvalImpl() otherwise returns getAsFloat()

Parameters:
xsink if an error occurs, the Qore-language exception information will be added here
Returns:
the result of the evaluation of the object

DLLEXPORT int64 AbstractQoreNode::getAsBigInt (  )  const

returns the 64-bit integer value of the object

calls getAsBitIntImpl() if necessary (there is an optimization for the QoreBigIntNode class) to return the integer value of the object

Referenced by get_bigint_param().

DLLEXPORT bool AbstractQoreNode::getAsBool (  )  const

returns the boolean value of the object

calls getAsBoolImpl() if necessary (there is an optimization for the QoreBoolNode class) to return the boolean value of the object

Referenced by get_bool_param().

DLLEXPORT double AbstractQoreNode::getAsFloat (  )  const

returns the float value of the object

calls getAsFloatImpl() if necessary (there is an optimization for the QoreFloatNode class) to return the floating-point value of the object

DLLEXPORT int AbstractQoreNode::getAsInt (  )  const

returns the integer value of the object

calls getAsIntImpl() if necessary (there is an optimization for the QoreBigIntNode class) to return the integer value of the object

Referenced by get_int_param().

virtual DLLEXPORT QoreString* AbstractQoreNode::getAsString ( bool &  del,
int  foff,
ExceptionSink xsink 
) const [pure virtual]

returns a QoreString giving the verbose string representation of the value (including all contained values for container types)

Used for n and N printf formatting. Do not call this function directly; use the QoreNodeAsStringHelper class (defined in QoreStringNode.h) instead

Parameters:
del if this is true when the function returns, then the returned QoreString pointer should be deleted, if false, then it must not be
foff for multi-line formatting offset, -1 = no line breaks
xsink if an error occurs, the Qore-language exception information will be added here
See also:
QoreNodeAsStringHelper

Implemented in BinaryNode, AbstractCallReferenceNode, DateTimeNode, QoreBigIntNode, QoreBoolNode, QoreFloatNode, QoreHashNode, QoreListNode, QoreNothingNode, QoreNullNode, QoreObject, QoreStringNode, and ReferenceNode.

virtual DLLEXPORT int AbstractQoreNode::getAsString ( QoreString str,
int  foff,
ExceptionSink xsink 
) const [pure virtual]

concatenate the verbose string representation of the value (including all contained values for container types) to an existing QoreString

used for n and N printf formatting

Parameters:
str the string representation of the type will be concatenated to this QoreString reference
foff for multi-line formatting offset, -1 = no line breaks
xsink if an error occurs, the Qore-language exception information will be added here
Returns:
-1 for exception raised, 0 = OK

Implemented in BinaryNode, AbstractCallReferenceNode, DateTimeNode, QoreBigIntNode, QoreBoolNode, QoreFloatNode, QoreHashNode, QoreListNode, QoreNothingNode, QoreNullNode, QoreObject, QoreStringNode, and ReferenceNode.

Referenced by QoreNodeAsStringHelper::QoreNodeAsStringHelper().

virtual DLLEXPORT void AbstractQoreNode::getDateTimeRepresentation ( DateTime dt  )  const [virtual]

assigns the date representation of a value to the DateTime reference passed, default implementation does nothing

Parameters:
dt the DateTime reference to be assigned

Reimplemented in DateTimeNode, QoreBigIntNode, QoreBoolNode, QoreFloatNode, and QoreStringNode.

virtual DLLEXPORT class DateTime* AbstractQoreNode::getDateTimeRepresentation ( bool &  del  )  const [virtual]

returns the DateTime representation of this type (default implementation: returns ZeroDate, del = false)

NOTE: Use the DateTimeValueHelper class instead of using this function directly

Parameters:
del output parameter: if del is true, then the returned DateTime pointer belongs to the caller (and must be deleted manually), if false, then it must not be
See also:
DateTimeValueHelper

Reimplemented in DateTimeNode, QoreBigIntNode, QoreBoolNode, QoreFloatNode, and QoreStringNode.

Referenced by DateTimeNodeValueHelper::DateTimeNodeValueHelper(), and DateTimeValueHelper::DateTimeValueHelper().

virtual DLLEXPORT void AbstractQoreNode::getStringRepresentation ( QoreString str  )  const [virtual]

concatentates the value of the type to an existing QoreString reference, default implementation does nothing

Parameters:
str a reference to a QoreString where the value of the type will be concatenated

Reimplemented in DateTimeNode, QoreBigIntNode, QoreBoolNode, QoreFloatNode, and QoreStringNode.

virtual DLLEXPORT QoreString* AbstractQoreNode::getStringRepresentation ( bool &  del  )  const [virtual]

returns the value of the type converted to a string, default implementation: returns the empty string

NOTE: do not use this function directly, use QoreStringValueHelper instead

Parameters:
del output parameter: if del is true, then the resulting QoreString pointer belongs to the caller (and must be deleted manually), if false it must not be
Returns:
a QoreString pointer, use the del output parameter to determine ownership of the pointer
See also:
QoreStringValueHelper

Reimplemented in DateTimeNode, QoreBigIntNode, QoreBoolNode, QoreFloatNode, and QoreStringNode.

Referenced by QoreStringValueHelper::QoreStringValueHelper().

DLLLOCAL qore_type_t AbstractQoreNode::getType (  )  const [inline]

virtual DLLEXPORT const char* AbstractQoreNode::getTypeName (  )  const [pure virtual]

returns the type name as a c string

Returns:
the type name as a c string

Implemented in BinaryNode, AbstractCallReferenceNode, DateTimeNode, QoreBigIntNode, QoreBoolNode, QoreFloatNode, QoreHashNode, QoreListNode, QoreNothingNode, QoreNullNode, QoreObject, QoreStringNode, and ReferenceNode.

DLLEXPORT int AbstractQoreNode::integerEval ( ExceptionSink xsink  )  const

evaluates the object and returns an integer value

if needs_eval() returns true, then returns integerEvalImpl() otherwise returns getAsInteger()

Parameters:
xsink if an error occurs, the Qore-language exception information will be added here
Returns:
the result of the evaluation of the object

virtual DLLEXPORT bool AbstractQoreNode::is_equal_hard ( const AbstractQoreNode v,
ExceptionSink xsink 
) const [pure virtual]

tests for equality ("deep compare" including all contained values for container types) without type conversions (hard compare)

Parameters:
v the value to compare
xsink if an error occurs, the Qore-language exception information will be added here
Returns:
true if the objects are equal, false if not

Implemented in BinaryNode, DateTimeNode, QoreBigIntNode, QoreBoolNode, QoreFloatNode, QoreHashNode, QoreListNode, QoreNothingNode, QoreNullNode, QoreObject, QoreStringNode, and ReferenceNode.

virtual DLLEXPORT bool AbstractQoreNode::is_equal_soft ( const AbstractQoreNode v,
ExceptionSink xsink 
) const [pure virtual]

tests for equality ("deep compare" including all contained values for container types) with possible type conversion (soft compare)

Parameters:
v the value to compare
xsink if an error occurs, the Qore-language exception information will be added here
Returns:
true if the objects are equal, false if not

Implemented in BinaryNode, DateTimeNode, QoreBigIntNode, QoreBoolNode, QoreFloatNode, QoreHashNode, QoreListNode, QoreNothingNode, QoreNullNode, QoreObject, QoreStringNode, and ReferenceNode.

DLLLOCAL bool AbstractQoreNode::is_value (  )  const [inline]

returns true if the node represents a value

Returns:
true if the object is a value, false if not

References value.

DLLLOCAL bool AbstractQoreNode::needs_eval (  )  const [inline]

returns true if the object needs evaluation to return a value, false if not

default implementation returns false

Returns:
true if the type supports evaluation of this object, false if not

References needs_eval_flag.

virtual DLLEXPORT AbstractQoreNode* AbstractQoreNode::parseInit ( LocalVar *  oflag,
int  pflag,
int &  lvids 
) [inline, virtual]

for use by parse types to initialize them for execution during stage 1 parsing

Note:
: not yet universally used This function should only be overridden by types that can appear in the parse tree (i.e. are recognized by the parser)
Parameters:
oflag non-zero if initialized within class code
pflag bitfield parse flag
lvids the number of new local variables declared in this node
Returns:
new object

virtual DLLEXPORT AbstractQoreNode* AbstractQoreNode::realCopy (  )  const [pure virtual]

returns a copy of the object; the caller owns the reference count

Returns:
a copy of the object; the caller owns the reference count

Implemented in UniqueValueQoreNode, BinaryNode, DateTimeNode, QoreBigIntNode, QoreFloatNode, QoreHashNode, QoreListNode, QoreObject, QoreStringNode, and ReferenceNode.

DLLEXPORT AbstractQoreNode* AbstractQoreNode::refSelf (  )  const

returns "this" with an incremented reference count

Returns:
"this" with an incremented reference count


Member Data Documentation

the type of the object

instead of using a virtual method to return a default type code for each implemented type, it's stored as an attribute of the base class. This makes it possible to avoid making virtual function calls as a performance optimization in many cases, also it allows very fast type determination without makiing either a virtual function call or using dynamic_cast<> at the expense of more memory usage

Referenced by getType().


The documentation for this class was generated from the following file:

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