Qore Programming Language  0.9.16
QoreNullNode.h
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1 /* -*- mode: c++; indent-tabs-mode: nil -*- */
2 /*
3  QoreNullNode.h
4 
5  Qore Programming Language
6 
7  Copyright (C) 2003 - 2018 Qore Technologies, s.r.o.
8 
9  Permission is hereby granted, free of charge, to any person obtaining a
10  copy of this software and associated documentation files (the "Software"),
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27  Note that the Qore library is released under a choice of three open-source
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30 */
31 
32 #ifndef _QORE_QORENULLNODE_H
33 
34 #define _QORE_QORENULLNODE_H
35 
36 #include <qore/AbstractQoreNode.h>
37 
42 
51 private:
53  DLLLOCAL virtual bool getAsBoolImpl() const;
54 
56  DLLLOCAL virtual int getAsIntImpl() const;
57 
59  DLLLOCAL virtual int64 getAsBigIntImpl() const;
60 
62  DLLLOCAL virtual double getAsFloatImpl() const;
63 
64 protected:
66 
69  DLLLOCAL QoreValue evalImpl(bool& needs_deref, ExceptionSink* xsink) const;
70 
71 public:
72  DLLEXPORT QoreNullNode();
73 
74  DLLEXPORT virtual ~QoreNullNode();
75 
77 
83  DLLEXPORT virtual int getAsString(QoreString &str, int foff, class ExceptionSink *xsink) const;
84 
86 
93  DLLEXPORT virtual QoreString *getAsString(bool &del, int foff, class ExceptionSink *xsink) const;
94 
96 
100  DLLEXPORT virtual bool is_equal_soft(const AbstractQoreNode *v, ExceptionSink *xsink) const;
101 
103 
107  DLLEXPORT virtual bool is_equal_hard(const AbstractQoreNode *v, ExceptionSink *xsink) const;
108 
110  DLLEXPORT virtual const char *getTypeName() const;
111 
113  DLLLOCAL virtual void parseInit(QoreValue& val, LocalVar *oflag, int pflag, int &lvids, const QoreTypeInfo *&returnTypeInfo);
114 
116  DLLLOCAL static const char *getStaticTypeName() {
117  return "NULL";
118  }
119 
121  DLLLOCAL static qore_type_t getStaticTypeCode() {
122  return NT_NULL;
123  }
124 
125  static const qore_type_t TYPE = NT_NULL;
126 };
127 
129 static inline bool is_null(const AbstractQoreNode *n) {
130  // this is faster than a dynamic_cast<const QoreNullNode *> operation
131  return n && n->getType() == NT_NULL;
132 }
133 
135 DLLEXPORT extern QoreNullNode Null;
136 
138 static inline QoreNullNode *null() {
139  return &Null;
140 }
141 
142 #endif
QoreNullNode::getStaticTypeName
static const DLLLOCAL char * getStaticTypeName()
returns the type name (useful in templates)
Definition: QoreNullNode.h:116
QoreValue
The main value class in Qore, designed to be passed by value.
Definition: QoreValue.h:262
AbstractQoreNode::getType
DLLLOCAL qore_type_t getType() const
returns the data type
Definition: AbstractQoreNode.h:172
QoreNullNode::getStaticTypeCode
static DLLLOCAL qore_type_t getStaticTypeCode()
returns the type code (useful in templates)
Definition: QoreNullNode.h:121
QoreNullNode::getTypeName
virtual const DLLEXPORT char * getTypeName() const
returns the type name as a c string
int64
long long int64
64bit integer type, cannot use int64_t here since it breaks the API on some 64-bit systems due to equ...
Definition: common.h:260
QoreNullNode
Qore's SQL "NULL" parse tree/value type, not-referenced counted, not dynamically allocated.
Definition: QoreNullNode.h:50
is_null
static bool is_null(const AbstractQoreNode *n)
use this function to test for NULL
Definition: QoreNullNode.h:129
QoreString
Qore's string type supported by the QoreEncoding class.
Definition: QoreString.h:81
QoreNullNode::parseInit
virtual DLLLOCAL void parseInit(QoreValue &val, LocalVar *oflag, int pflag, int &lvids, const QoreTypeInfo *&returnTypeInfo)
returns the type information
QoreNullNode::getAsString
virtual DLLEXPORT int getAsString(QoreString &str, int foff, class ExceptionSink *xsink) const
concatenate "<NULL>" to an existing QoreString
ExceptionSink
container for holding Qore-language exception information and also for registering a "thread_exit" ca...
Definition: ExceptionSink.h:48
UniqueValueQoreNode
this class is for value types that will exists only once in the Qore library, reference counting is d...
Definition: AbstractQoreNode.h:383
NT_NULL
const qore_type_t NT_NULL
type value for QoreNullNode
Definition: node_types.h:48
Null
DLLEXPORT QoreNullNode Null
the global and unique NULL value in Qore
QoreNullNode::evalImpl
DLLLOCAL QoreValue evalImpl(bool &needs_deref, ExceptionSink *xsink) const
should never be called for value types
SimpleValueQoreNode::evalImpl
virtual DLLEXPORT QoreValue evalImpl(bool &needs_deref, ExceptionSink *xsink) const
should never be called for value types
AbstractQoreNode
The base class for all value and parse types in Qore expression trees.
Definition: AbstractQoreNode.h:54
qore_type_t
int16_t qore_type_t
used to identify unique Qore data and parse types (descendents of AbstractQoreNode)
Definition: common.h:70
QoreNullNode::is_equal_hard
virtual DLLEXPORT bool is_equal_hard(const AbstractQoreNode *v, ExceptionSink *xsink) const
tests for equality without type conversions (hard compare)
QoreNullNode::is_equal_soft
virtual DLLEXPORT bool is_equal_soft(const AbstractQoreNode *v, ExceptionSink *xsink) const
tests for equality with possible type conversion (soft compare)