OpenVDB 12.1.0

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Attribute Struct Reference

Attributes represent any access to a primitive value, typically associated with the '@' symbol syntax. Note that the AST does not store any additional information on the given attribute other than its name and type, which together form a unique Attribute identifier known as the Attribute 'token'. A 'primitive value' in this instance refers to a value on an OpenVDB Volume or OpenVDB Points tree. More...

`#include <openvdb_ax/ast/AST.h>`

Inheritance diagram for Attribute:

## Public Types
using | UniquePtr = std::unique_ptr<Attribute>
enum | NodeType { TreeNode , StatementListNode , BlockNode , ConditionalStatementNode , CommaOperatorNode , LoopNode , KeywordNode , AssignExpressionNode , CrementNode , UnaryOperatorNode , BinaryOperatorNode , TernaryOperatorNode , CastNode , AttributeNode , FunctionCallNode , ExternalVariableNode , DeclareLocalNode , ArrayPackNode , ArrayUnpackNode , LocalNode , ValueBoolNode , ValueInt16Node , ValueInt32Node , ValueInt64Node , ValueFloatNode , ValueDoubleNode , ValueStrNode }
| An enumerated list of node types for all concrete node types. These can be used for faster evaluation of a given concrete node using the virtual function table via Node::nodetype() rather than performing a dynamic_cast/calling Node::isType. More...
using | Ptr = std::shared_ptr<Node>

## Public Member Functions
| Attribute (const std::string &name, const tokens::CoreType type, const bool inferred=false)
| Construct a new Attribute with a given name and type. Optionally also mark it as inferred type creation (no type was directly specified)
| Attribute (const std::string &name, const std::string &token, const bool inferred=false)
| Construct a new Attribute with a given name and type/token string, delegating construction to the above Attribute constructor.
| Attribute (const Attribute &other)
| Deep copy constructor for a Attribute.
| ~Attribute () override=default
Attribute * | copy () const override final
| The deep copy method for a Node.
NodeType | nodetype () const override
| Virtual method for accessing node type information.
const char * | nodename () const override
| Virtual method for accessing node name information.
const char * | subname () const override
| Virtual method for accessing node name information.
const Variable * | basetype () const override
| Virtual method for accessing a node's base class. Note that if this is called explicitly on an instance of ast::Node (the top most base class) a nullptr is returned. This is primarily used by the Visitor to support hierarchical visits.
bool | inferred () const
| Query whether this attribute was accessed via inferred syntax i.e. @P or @myattribute.
tokens::CoreType | type () const
| Access the type that was used to access this attribute.
std::string | typestr () const
| Get the access type as a front end AX type/token string.
std::string | tokenname () const
| Construct and return the full attribute token identifier. See Attribute::tokenFromNameType.
size_t | children () const override
| Virtual method for accessing child information. Returns the number of children a given AST node owns.
const Node * | child (const size_t) const override
| Virtual method for accessing child information. Returns a const pointer to a child node at the given index. If the index is out of range, a nullptr is returned.
const std::string & | name () const
Name/Type
template<typename NodeT>
bool | isType () const
| Query whether or not this node is of a specific (derived) type. This method should be used to check if a node is of a particular abstract type. When checking concrete types, it's generally more efficient to check the return value of Node::nodetype()
Child Queries
int64_t | childidx () const
| Returns the child index of this node in relation to its parent, or -1 if no valid index is found (usually representing the top most node (i.e. Tree)
Replacement
bool | replace (Node *node)
| In place replacement. Attempts to replace this node at its specific location within its Abstract Syntax Tree. On a successful replacement, this node is destroyed, the provided node is inserted in its place and ownership is transferred to the parent node. No further calls to this node can be made on successful replacements.
virtual bool | replacechild (const size_t index, Node *node)
| Virtual method that attempted to replace a child at a given index with a provided node type.
Parent
const Node * | parent () const
| Access a const pointer to this nodes parent.
void | setParent (Node *parent)
| Set this node's parent. This is used during construction of an AST and should not be used.

## Static Public Member Functions
static char | symbolseparator ()
| Static method returning the symbol associated with an Attribute access as defined by AX Grammar.
static std::string | tokenFromNameType (const std::string &name, const tokens::CoreType type)
| Static method returning the full unique attribute token identifier by consolidating its name and type such that token = tokenstr + '@' + name, where tokenstr is the AX type token as a string, converted from the provided CoreType.
static bool | nametypeFromToken (const std::string &token, std::string *name, std::string *type)
| Static method which splits a valid attribute token into its name and type counterparts. If the token cannot be split, neither name or type are updated and false is returned.

## Detailed Description

Attributes represent any access to a primitive value, typically associated with the '@' symbol syntax. Note that the AST does not store any additional information on the given attribute other than its name and type, which together form a unique Attribute identifier known as the Attribute 'token'. A 'primitive value' in this instance refers to a value on an OpenVDB Volume or OpenVDB Points tree.

Note
  The ExternalVariable AST node works in a similar way
  An Attribute is a complete "leaf-level" AST node. It has no children and nothing derives from it.

## Member Typedef Documentation

## ◆ Ptr

using Ptr = std::shared_ptr<Node>
| inherited

## ◆ UniquePtr

using UniquePtr = std::unique_ptr<Attribute>

## Member Enumeration Documentation

## ◆ NodeType

enum NodeType
| inherited

An enumerated list of node types for all concrete node types. These can be used for faster evaluation of a given concrete node using the virtual function table via Node::nodetype() rather than performing a dynamic_cast/calling Node::isType.

Note
  This is sometimes referred to as "manual RTTI". We use this technique combine with single dispatch due to opting for CRTP on the main visitor and no templated virtual method support in C++. i.e. no way to double dispatch: visit<template T>(Visitor<T>*)
  Abstract (pure-virtual) nodes are not listed here. Node::isType should be used to determine if a node is of a given abstract type.

Enumerator
TreeNode |
StatementListNode |
BlockNode |
ConditionalStatementNode |
CommaOperatorNode |
LoopNode |
KeywordNode |
AssignExpressionNode |
CrementNode |
UnaryOperatorNode |
BinaryOperatorNode |
TernaryOperatorNode |
CastNode |
AttributeNode |
FunctionCallNode |
ExternalVariableNode |
DeclareLocalNode |
ArrayPackNode |
ArrayUnpackNode |
LocalNode |
ValueBoolNode |
ValueInt16Node |
ValueInt32Node |
ValueInt64Node |
ValueFloatNode |
ValueDoubleNode |
ValueStrNode |

## Constructor & Destructor Documentation

## ◆ Attribute() [1/3]

Attribute | ( | const std::string & | name,
|  | const tokens::CoreType | type,
|  | const bool | inferred = false )
| inline

Construct a new Attribute with a given name and type. Optionally also mark it as inferred type creation (no type was directly specified)

Parameters

  name | The name of the attribute
  type | The type of the attribute
  inferred | Whether the provided type was directly specified (false).

## ◆ Attribute() [2/3]

Attribute | ( | const std::string & | name,
|  | const std::string & | token,
|  | const bool | inferred = false )
| inline

Construct a new Attribute with a given name and type/token string, delegating construction to the above Attribute constructor.

Parameters

  name | The name of the attribute
  token | The type/token string of the attribute
  inferred | Whether the provided type was directly specified (false).

## ◆ Attribute() [3/3]

Attribute | ( | const Attribute & | other | ) |
| inline

Deep copy constructor for a Attribute.

Note
  No parent information needs updating as an Attribute is a "leaf level" node (contains no children)

Parameters

  other | A const reference to another Attribute to deep copy

## ◆ ~Attribute()

~Attribute | ( |  | ) |
| override default

## Member Function Documentation

## ◆ basetype()

const Variable * basetype | ( |  | ) | const
| inline override virtual

Virtual method for accessing a node's base class. Note that if this is called explicitly on an instance of ast::Node (the top most base class) a nullptr is returned. This is primarily used by the Visitor to support hierarchical visits.

Reimplemented from Node.

## ◆ child()

const Node * child | ( | const size_t | index | ) | const
| inline override virtual inherited

Virtual method for accessing child information. Returns a const pointer to a child node at the given index. If the index is out of range, a nullptr is returned.

Note
  This may still return a nullptr even if the given index is valid if the child node has not been created.

Parameters

  index | The child index to query

Returns
  A Pointer to the child node, or a nullptr if none exists.

Implements Node.

## ◆ childidx()

int64_t childidx | ( |  | ) | const
| inline inherited

Returns the child index of this node in relation to its parent, or -1 if no valid index is found (usually representing the top most node (i.e. Tree)

Returns
  The child index of this node

## ◆ children()

size_t children | ( |  | ) | const
| inline override virtual inherited

Virtual method for accessing child information. Returns the number of children a given AST node owns.

Returns
  The number of children this node owns.

Implements Node.

## ◆ copy()

Attribute * copy | ( |  | ) | const
| inline final override virtual

The deep copy method for a Node.

Implements Variable.

## ◆ inferred()

bool inferred | ( |  | ) | const
| inline

Query whether this attribute was accessed via inferred syntax i.e. @P or @myattribute.

Returns
  True if inferred syntax was used

## ◆ isType()

template<typename NodeT>

bool isType | ( |  | ) | const
| inline inherited

Query whether or not this node is of a specific (derived) type. This method should be used to check if a node is of a particular abstract type. When checking concrete types, it's generally more efficient to check the return value of Node::nodetype()

Template Parameters

  NodeT | The node type to query against.

Returns
  True if this node is of the given type, false otherwise.

## ◆ name()

const std::string & name | ( |  | ) | const
| inline inherited

## ◆ nametypeFromToken()

bool nametypeFromToken | ( | const std::string & | token,
|  | std::string * | name,
|  | std::string * | type )
| inline static

Static method which splits a valid attribute token into its name and type counterparts. If the token cannot be split, neither name or type are updated and false is returned.

Parameters

  token | The token to split.
  name | Set to the second part of the attribute token, representing the name. If a nullptr, it is ignored
  type | Set to the first part of the attribute token, representing the type. If a nullptr, it is ignored. Note that this can be empty if the attribute token has an inferred type or a single character.

Returns
  True if the provided attribute token could be split

## ◆ nodename()

const char * nodename | ( |  | ) | const
| inline override virtual

Virtual method for accessing node name information.

Implements Node.

## ◆ nodetype()

NodeType nodetype | ( |  | ) | const
| inline override virtual

Virtual method for accessing node type information.

Implements Node.

## ◆ parent()

const Node * parent | ( |  | ) | const
| inline inherited

Access a const pointer to this nodes parent.

Note
  Can be a nullptr if this is the top most node in an AST (usually a Tree)

Returns
  A const pointer to this node's parent node

## ◆ replace()

bool replace | ( | Node * | node | ) |
| inline inherited

In place replacement. Attempts to replace this node at its specific location within its Abstract Syntax Tree. On a successful replacement, this node is destroyed, the provided node is inserted in its place and ownership is transferred to the parent node. No further calls to this node can be made on successful replacements.

Note
  A replacement will fail if this node is the top most node within an AST hierarchy or if the provided node type is not a compatible type for the required abstract storage. For example, if this node is an Attribute being held on a BinaryOperator, only concrete nodes derived from an Expression can be used as a replacement.
  This method will dynamic_cast the provided node to check to see if it's a compatible type.

Parameters

  node | The node to insert on a successful replacement.

Returns
  True if the replacement was successful, resulting in destruction of this class and ownership transferal of the provided node. False otherwise, where this and the provided node are unchanged.

## ◆ replacechild()

bool replacechild | ( | const size_t | index,
|  | Node * | node )
| inline virtual inherited

Virtual method that attempted to replace a child at a given index with a provided node type.

Note
  See Node::replace for a more detailed description

Parameters

  index | The child index where a replacement should be attempted
  node | The node to insert on a successful replacement.

Returns
  True if the replacement was successful, false otherwise

Reimplemented in ArrayPack, ArrayUnpack, AssignExpression, BinaryOperator, Block, Cast, CommaOperator, ConditionalStatement, Crement, DeclareLocal, FunctionCall, Loop, StatementList, TernaryOperator, and UnaryOperator.

## ◆ setParent()

void setParent | ( | Node * | parent | ) |
| inline inherited

Set this node's parent. This is used during construction of an AST and should not be used.

Parameters

  parent | The parent to set

## ◆ subname()

const char * subname | ( |  | ) | const
| inline override virtual

Virtual method for accessing node name information.

Implements Node.

## ◆ symbolseparator()

char symbolseparator | ( |  | ) |
| inline static

Static method returning the symbol associated with an Attribute access as defined by AX Grammar.

Returns
  The '@' character as a char

## ◆ tokenFromNameType()

std::string tokenFromNameType | ( | const std::string & | name,
|  | const tokens::CoreType | type )
| inline static

Static method returning the full unique attribute token identifier by consolidating its name and type such that token = tokenstr + '@' + name, where tokenstr is the AX type token as a string, converted from the provided CoreType.

Note
  This identifier is unique for accesses to the same attribute
  Due to inferred and single character accesses in AX, this return value does not necessarily represent the original syntax used to access this attribute. For example, @myattrib will be stored and returned as float@myattrib.

Parameters

  name | The name of the attribute
  type | The CoreType of the attribute

Returns
  A string representing the attribute token.

## ◆ tokenname()

std::string tokenname | ( |  | ) | const
| inline

Construct and return the full attribute token identifier. See Attribute::tokenFromNameType.

Returns
  A string representing the attribute token.

## ◆ type()

tokens::CoreType type | ( |  | ) | const
| inline

Access the type that was used to access this attribute.

Returns
  The type used to access this attribute as a tokens::CoreType

## ◆ typestr()

std::string typestr | ( |  | ) | const
| inline

Get the access type as a front end AX type/token string.

Note
  This returns the associated token to the type, not necessarily equal to the OpenVDB type string

Returns
  A string representing the type/token