Symbol

java.lang.Object
- com.oracle.js.parser.ir.Symbol

All Implemented Interfaces:

Comparable<Symbol>
```
public final class Symbol
extends Object
implements Comparable<Symbol>
```
Symbol is a symbolic address for a value ("variable" if you wish). Identifiers in JavaScript source, as well as certain synthetic variables created by the compiler are represented by Symbol objects. Symbols can address either local variable slots in bytecode ("slotted symbol"), or properties in scope objects ("scoped symbol"). A symbol can also end up being defined but then not used during symbol assignment calculations; such symbol will be neither scoped, nor slotted; it represents a dead variable (it might be written to, but is never read). Finally, a symbol can be both slotted and in scope. This special case can only occur with bytecode method parameters. They all come in as slotted, but if they are used by a nested function (or eval) then they will be copied into the scope object, and used from there onwards. Two further special cases are parameters stored in NativeArguments objects and parameters stored in Object[] parameter to variable-arity functions. Those use the #getFieldIndex() property to refer to their location.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`HAS_BEEN_DECLARED` Is this symbol seen a declaration? Used for block scoped LET and CONST symbols only.
`static int`	`IS_BLOCK_FUNCTION_DECLARATION` Is this symbol a block function declaration?
`static int`	`IS_CATCH_PARAMETER` Is this symbol a catch parameter binding?
`static int`	`IS_CONST` Is this a const binding
`static int`	`IS_DECLARED_IN_SWITCH_BLOCK` Is this symbol declared in an unprotected switch case context?
`static int`	`IS_FUNCTION_SELF` Is this a function self-reference symbol
`static int`	`IS_GLOBAL` Is this a global binding
`static int`	`IS_HOISTABLE_DECLARATION` Is this a hoistable var declaration?
`static int`	`IS_HOISTED_BLOCK_FUNCTION` Is this symbol a block function declaration hoisted into the body scope.
`static int`	`IS_IMPORT_BINDING` Is this symbol an indirect import binding of a module environment?
`static int`	`IS_INTERNAL` Is this an internal symbol, never represented explicitly in source code
`static int`	`IS_LET` Is this a let binding
`static int`	`IS_PARAM` Is this a parameter
`static int`	`IS_PRIVATE_NAME` Is this symbol a private name?
`static int`	`IS_PRIVATE_NAME_ACCESSOR` Is this symbol a private name associated with an accessor?
`static int`	`IS_PRIVATE_NAME_METHOD` Is this symbol a private name associated with a method?
`static int`	`IS_PRIVATE_NAME_STATIC` Is this symbol a private name associated with a static member?
`static int`	`IS_PROGRAM_LEVEL` Is this a program level symbol?
`static int`	`IS_THIS` Is this a this symbol
`static int`	`IS_VAR` Is this a var binding
`static int`	`IS_VAR_REDECLARED_HERE` Is this symbol a var declaration binding that needs to be initialized with the value of the parent's scope's binding with the same name? Used for parameter bindings that are replicated in the body's VariableEnvironment.
`static int`	`KINDMASK` Mask for kind flags

Constructor Summary

Constructors
Constructor and Description

Symbol(String name, int flags)
Constructor

Constructors
Constructor and Description
`Symbol(String name, int flags)` Constructor

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`compareTo(Symbol other)`
`int`	`getFlags()` Get the symbol flags
`String`	`getName()` Get the name of this symbol
`int`	`getUseCount()` Get the symbol's use count
`boolean`	`hasBeenDeclared()` Has this symbol been declared
`boolean`	`isBlockFunctionDeclaration()` Is this symbol a block function declaration.
`boolean`	`isBlockScoped()` Is this a block scoped symbol
`boolean`	`isCatchParameter()`
`boolean`	`isConst()` Check if this symbol is a constant
`boolean`	`isDeclaredInSwitchBlock()` Has this symbol been declared
`boolean`	`isFunctionSelf()` Flag this symbol as a function's self-referencing symbol.
`boolean`	`isGlobal()` Check if this symbol is a global (undeclared) variable
`boolean`	`isHoistableDeclaration()` Check if this symbol is a hoistable var declaration.
`boolean`	`isHoistedBlockFunctionDeclaration()` Is this symbol a hoisted block function declaration.
`boolean`	`isImportBinding()`
`boolean`	`isInternal()` Check if this is an internal symbol, without an explicit JavaScript source code equivalent
`boolean`	`isLet()` Check if this symbol is a let
`boolean`	`isParam()` Check if this symbol is a function parameter
`boolean`	`isPrivateAccessor()` Is this symbol a private name associated with an accessor.
`boolean`	`isPrivateField()` Is this symbol a private name associated with a field.
`boolean`	`isPrivateMethod()` Is this symbol a private name associated with a method.
`boolean`	`isPrivateName()` Is this symbol a private name.
`boolean`	`isPrivateNameStatic()` Is this symbol a private name associated with a static member.
`boolean`	`isProgramLevel()` Check if this is a program (script) level definition
`boolean`	`isThis()` Check if this symbol represents `this`
`boolean`	`isVar()` Check if this symbol is a variable
`boolean`	`isVarRedeclaredHere()`
`void`	`setHasBeenDeclared()` Mark this symbol as declared
`void`	`setHasBeenDeclared(boolean declared)` Mark this symbol as declared/undeclared
`void`	`setHoistedBlockFunctionDeclaration()` Mark this symbol as a hoisted block function declaration.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - IS_LET
```
public static final int IS_LET
```
    Is this a let binding
    
    See Also:
    
    Constant Field Values
  - IS_CONST
```
public static final int IS_CONST
```
    Is this a const binding
    
    See Also:
    
    Constant Field Values
  - IS_VAR
```
public static final int IS_VAR
```
    Is this a var binding
    
    See Also:
    
    Constant Field Values
  - KINDMASK
```
public static final int KINDMASK
```
    Mask for kind flags
    
    See Also:
    
    Constant Field Values
  - IS_GLOBAL
```
public static final int IS_GLOBAL
```
    Is this a global binding
    
    See Also:
    
    Constant Field Values
  - IS_PARAM
```
public static final int IS_PARAM
```
    Is this a parameter
    
    See Also:
    
    Constant Field Values
  - IS_THIS
```
public static final int IS_THIS
```
    Is this a this symbol
    
    See Also:
    
    Constant Field Values
  - IS_INTERNAL
```
public static final int IS_INTERNAL
```
    Is this an internal symbol, never represented explicitly in source code
    
    See Also:
    
    Constant Field Values
  - IS_FUNCTION_SELF
```
public static final int IS_FUNCTION_SELF
```
    Is this a function self-reference symbol
    
    See Also:
    
    Constant Field Values
  - IS_HOISTABLE_DECLARATION
```
public static final int IS_HOISTABLE_DECLARATION
```
    Is this a hoistable var declaration?
    
    See Also:
    
    Constant Field Values
  - IS_PROGRAM_LEVEL
```
public static final int IS_PROGRAM_LEVEL
```
    Is this a program level symbol?
    
    See Also:
    
    Constant Field Values
  - HAS_BEEN_DECLARED
```
public static final int HAS_BEEN_DECLARED
```
    Is this symbol seen a declaration? Used for block scoped LET and CONST symbols only.
    
    See Also:
    
    Constant Field Values
  - IS_HOISTED_BLOCK_FUNCTION
```
public static final int IS_HOISTED_BLOCK_FUNCTION
```
    Is this symbol a block function declaration hoisted into the body scope.
    
    See Also:
    
    Constant Field Values
  - IS_VAR_REDECLARED_HERE
```
public static final int IS_VAR_REDECLARED_HERE
```
    Is this symbol a var declaration binding that needs to be initialized with the value of the parent's scope's binding with the same name? Used for parameter bindings that are replicated in the body's VariableEnvironment.
    
    See Also:
    
    Constant Field Values
  - IS_DECLARED_IN_SWITCH_BLOCK
```
public static final int IS_DECLARED_IN_SWITCH_BLOCK
```
    Is this symbol declared in an unprotected switch case context?
    
    See Also:
    
    Constant Field Values
  - IS_IMPORT_BINDING
```
public static final int IS_IMPORT_BINDING
```
    Is this symbol an indirect import binding of a module environment?
    
    See Also:
    
    Constant Field Values
  - IS_CATCH_PARAMETER
```
public static final int IS_CATCH_PARAMETER
```
    Is this symbol a catch parameter binding?
    
    See Also:
    
    Constant Field Values
  - IS_BLOCK_FUNCTION_DECLARATION
```
public static final int IS_BLOCK_FUNCTION_DECLARATION
```
    Is this symbol a block function declaration?
    
    See Also:
    
    Constant Field Values
  - IS_PRIVATE_NAME
```
public static final int IS_PRIVATE_NAME
```
    Is this symbol a private name?
    
    See Also:
    
    Constant Field Values
  - IS_PRIVATE_NAME_STATIC
```
public static final int IS_PRIVATE_NAME_STATIC
```
    Is this symbol a private name associated with a static member?
    
    See Also:
    
    Constant Field Values
  - IS_PRIVATE_NAME_METHOD
```
public static final int IS_PRIVATE_NAME_METHOD
```
    Is this symbol a private name associated with a method?
    
    See Also:
    
    Constant Field Values
  - IS_PRIVATE_NAME_ACCESSOR
```
public static final int IS_PRIVATE_NAME_ACCESSOR
```
    Is this symbol a private name associated with an accessor?
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - Symbol
```
public Symbol(String name,
              int flags)
```
    Constructor
    
    Parameters:
    
    name - name of symbol
    
    flags - symbol flags
- Method Detail
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - compareTo
```
public int compareTo(Symbol other)
```
    Specified by:
    
    compareTo in interface Comparable<Symbol>
  - isHoistableDeclaration
```
public boolean isHoistableDeclaration()
```
    Check if this symbol is a hoistable var declaration.
    
    Returns:
    
    true if a hoistable var declaration
    
    See Also:
    
    VarNode.isHoistableDeclaration()
  - isVar
```
public boolean isVar()
```
    Check if this symbol is a variable
    
    Returns:
    
    true if variable
  - isGlobal
```
public boolean isGlobal()
```
    Check if this symbol is a global (undeclared) variable
    
    Returns:
    
    true if global
  - isParam
```
public boolean isParam()
```
    Check if this symbol is a function parameter
    
    Returns:
    
    true if parameter
  - isProgramLevel
```
public boolean isProgramLevel()
```
    Check if this is a program (script) level definition
    
    Returns:
    
    true if program level
  - isConst
```
public boolean isConst()
```
    Check if this symbol is a constant
    
    Returns:
    
    true if a constant
  - isInternal
```
public boolean isInternal()
```
    Check if this is an internal symbol, without an explicit JavaScript source code equivalent
    
    Returns:
    
    true if internal
  - isThis
```
public boolean isThis()
```
    Check if this symbol represents this
    
    Returns:
    
    true if this
  - isLet
```
public boolean isLet()
```
    Check if this symbol is a let
    
    Returns:
    
    true if let
  - isFunctionSelf
```
public boolean isFunctionSelf()
```
    Flag this symbol as a function's self-referencing symbol.
    
    Returns:
    
    true if this symbol as a function's self-referencing symbol.
  - isBlockScoped
```
public boolean isBlockScoped()
```
    Is this a block scoped symbol
    
    Returns:
    
    true if block scoped
  - hasBeenDeclared
```
public boolean hasBeenDeclared()
```
    Has this symbol been declared
    
    Returns:
    
    true if declared
  - setHasBeenDeclared
```
public void setHasBeenDeclared()
```
    Mark this symbol as declared
  - setHasBeenDeclared
```
public void setHasBeenDeclared(boolean declared)
```
    Mark this symbol as declared/undeclared
  - getFlags
```
public int getFlags()
```
    Get the symbol flags
    
    Returns:
    
    flags
  - getName
```
public String getName()
```
    Get the name of this symbol
    
    Returns:
    
    symbol name
  - getUseCount
```
public int getUseCount()
```
    Get the symbol's use count
    
    Returns:
    
    the number of times the symbol is used in code.
  - isDeclaredInSwitchBlock
```
public boolean isDeclaredInSwitchBlock()
```
    Has this symbol been declared
    
    Returns:
    
    true if declared
  - isImportBinding
```
public boolean isImportBinding()
```
    Returns:
    
    true if this symbol is an indirect import binding
    
    See Also:
    
    Symbol.IS_IMPORT_BINDING
  - isCatchParameter
```
public boolean isCatchParameter()
```
    Returns:
    
    true if this symbol is a catch parameter binding
    
    See Also:
    
    Symbol.IS_CATCH_PARAMETER
  - isVarRedeclaredHere
```
public boolean isVarRedeclaredHere()
```
  - isHoistedBlockFunctionDeclaration
```
public boolean isHoistedBlockFunctionDeclaration()
```
    Is this symbol a hoisted block function declaration.
  - setHoistedBlockFunctionDeclaration
```
public void setHoistedBlockFunctionDeclaration()
```
    Mark this symbol as a hoisted block function declaration.
  - isBlockFunctionDeclaration
```
public boolean isBlockFunctionDeclaration()
```
    Is this symbol a block function declaration.
  - isPrivateName
```
public boolean isPrivateName()
```
    Is this symbol a private name.
  - isPrivateNameStatic
```
public boolean isPrivateNameStatic()
```
    Is this symbol a private name associated with a static member.
  - isPrivateField
```
public boolean isPrivateField()
```
    Is this symbol a private name associated with a field.
  - isPrivateMethod
```
public boolean isPrivateMethod()
```
    Is this symbol a private name associated with a method.
  - isPrivateAccessor
```
public boolean isPrivateAccessor()
```
    Is this symbol a private name associated with an accessor.

Class Symbol

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

IS_LET

IS_CONST

IS_VAR

KINDMASK

IS_GLOBAL

IS_PARAM

IS_THIS

IS_INTERNAL

IS_FUNCTION_SELF

IS_HOISTABLE_DECLARATION

IS_PROGRAM_LEVEL

HAS_BEEN_DECLARED

IS_HOISTED_BLOCK_FUNCTION

IS_VAR_REDECLARED_HERE

IS_DECLARED_IN_SWITCH_BLOCK

IS_IMPORT_BINDING

IS_CATCH_PARAMETER

IS_BLOCK_FUNCTION_DECLARATION

IS_PRIVATE_NAME

IS_PRIVATE_NAME_STATIC

IS_PRIVATE_NAME_METHOD

IS_PRIVATE_NAME_ACCESSOR

Constructor Detail

Symbol

Method Detail

toString

compareTo

isHoistableDeclaration

isVar

isGlobal

isParam

isProgramLevel

isConst

isInternal

isThis

isLet

isFunctionSelf

isBlockScoped

hasBeenDeclared

setHasBeenDeclared

setHasBeenDeclared

getFlags

getName

getUseCount

isDeclaredInSwitchBlock

isImportBinding

isCatchParameter

isVarRedeclaredHere

isHoistedBlockFunctionDeclaration

setHoistedBlockFunctionDeclaration

isBlockFunctionDeclaration

isPrivateName

isPrivateNameStatic

isPrivateField

isPrivateMethod

isPrivateAccessor