Scope (Rhino)
Date: 2018-10-23

org.mozilla.javascript.ast

## Class Scope

- java.lang.Object
- - org.mozilla.javascript.Node
  - - org.mozilla.javascript.ast.AstNode
    - - org.mozilla.javascript.ast.Jump
      - - org.mozilla.javascript.ast.Scope

- All Implemented Interfaces:
    java.lang.Comparable<AstNode>, java.lang.Iterable<Node>
  Direct Known Subclasses:
    ArrayComprehension, GeneratorExpression, LetNode, Loop, ScriptNode

      public class Scope
      extends Jump

  Represents a scope in the lexical scope chain. Base type for all `AstNode` implementations that can introduce a new scope.

- - ### Nested Class Summary

    - ### Nested classes/interfaces inherited from class org.mozilla.javascript.ast.AstNode

      `AstNode.DebugPrintVisitor, AstNode.PositionComparator`

    - ### Nested classes/interfaces inherited from class org.mozilla.javascript.Node

      `Node.NodeIterator`

  - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `protected Scope` | `parentScope`
    `protected java.util.Map<java.lang.String,Symbol>` | `symbolTable`
    `protected ScriptNode` | `top`

    - ### Fields inherited from class org.mozilla.javascript.ast.Jump

      `target`

    - ### Fields inherited from class org.mozilla.javascript.ast.AstNode

      `length, parent, position`

    - ### Fields inherited from class org.mozilla.javascript.Node

      `ARROW_FUNCTION_PROP, ATTRIBUTE_FLAG, BOTH, CASEARRAY_PROP, CATCH_SCOPE_PROP, CONTROL_BLOCK_PROP, DECR_FLAG, DESCENDANTS_FLAG, DESTRUCTURING_ARRAY_LENGTH, DESTRUCTURING_NAMES, DESTRUCTURING_PARAMS, DESTRUCTURING_SHORTHAND, DIRECTCALL_PROP, END_DROPS_OFF, END_RETURNS, END_RETURNS_VALUE, END_UNREACHED, END_YIELDS, EXPRESSION_CLOSURE_PROP, first, FUNCTION_PROP, GENERATOR_END_PROP, INCRDECR_PROP, ISNUMBER_PROP, JSDOC_PROP, LABEL_ID_PROP, last, LAST_PROP, LEFT, lineno, LOCAL_BLOCK_PROP, LOCAL_PROP, MEMBER_TYPE_PROP, NAME_PROP, next, NON_SPECIALCALL, OBJECT_IDS_PROP, PARENTHESIZED_PROP, POST_FLAG, PROPERTY_FLAG, propListHead, REGEXP_PROP, RIGHT, SKIP_INDEXES_PROP, SPECIALCALL_EVAL, SPECIALCALL_PROP, SPECIALCALL_WITH, TARGETBLOCK_PROP, type, VARIABLE_PROP`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `Scope()`
    `Scope(int pos)`
    `Scope(int pos, int len)`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `addChildScope(Scope child)` Add a scope to our list of child scopes.
    `void` | `clearParentScope()` Used only for code generation.
    `java.util.List<Scope>` | `getChildScopes()` Return a list of the scopes whose parent is this scope.
    `Scope` | `getDefiningScope(java.lang.String name)` Returns the scope in which this name is defined
    `Scope` | `getParentScope()`
    `java.util.List<AstNode>` | `getStatements()` Returns a copy of the child list, with each child cast to an `AstNode`.
    `Symbol` | `getSymbol(java.lang.String name)` Looks up a symbol in this scope.
    `java.util.Map<java.lang.String,Symbol>` | `getSymbolTable()` Returns the symbol table for this scope.
    `ScriptNode` | `getTop()` Returns current script or function scope
    `static void` | `joinScopes(Scope source, Scope dest)` Copies all symbols from source scope to dest scope.
    `void` | `putSymbol(Symbol symbol)` Enters a symbol into this scope.
    `void` | `replaceWith(Scope newScope)` Used by the parser; not intended for typical use.
    `void` | `setParentScope(Scope parentScope)` Sets parent scope
    `void` | `setSymbolTable(java.util.Map<java.lang.String,Symbol> table)` Sets the symbol table for this scope.
    `void` | `setTop(ScriptNode top)` Sets top current script or function scope
    `static Scope` | `splitScope(Scope scope)` Creates a new scope node, moving symbol table information from "scope" to the new node, and making "scope" a nested scope contained by the new node.
    `java.lang.String` | `toSource(int depth)` Emits source code for this node.
    `void` | `visit(NodeVisitor v)` Jumps are only used directly during code generation, and do not support this interface.

    - ### Methods inherited from class org.mozilla.javascript.ast.Jump

      `getContinue, getDefault, getFinally, getJumpStatement, getLoop, setContinue, setDefault, setFinally, setJumpStatement, setLoop`

    - ### Methods inherited from class org.mozilla.javascript.ast.AstNode

      `addChild, assertNotNull, codeBug, compareTo, debugPrint, depth, getAbsolutePosition, getAstRoot, getEnclosingFunction, getEnclosingScope, getLength, getLineno, getParent, getPosition, hasSideEffects, makeIndent, operatorToString, printList, setBounds, setLength, setParent, setPosition, setRelative, shortName, toSource`

    - ### Methods inherited from class org.mozilla.javascript.Node

      `addChildAfter, addChildBefore, addChildrenToBack, addChildrenToFront, addChildToBack, addChildToFront, getChildBefore, getDouble, getExistingIntProp, getFirstChild, getIntProp, getJsDoc, getJsDocNode, getLastChild, getLastSibling, getNext, getProp, getScope, getString, getType, hasChildren, hasConsistentReturnUsage, iterator, labelId, labelId, newNumber, newString, newString, newTarget, putIntProp, putProp, removeChild, removeChildren, removeProp, replaceChild, replaceChildAfter, resetTargets, setDouble, setJsDocNode, setLineno, setScope, setString, setType, toString, toStringTree`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Field Detail

    - #### symbolTable

          protected java.util.Map<java.lang.String,Symbol> symbolTable

    - #### parentScope

          protected Scope parentScope

    - #### top

          protected ScriptNode top

  - ### Constructor Detail

    - #### Scope

          public Scope()

    - #### Scope

          public Scope(int pos)

    - #### Scope

          public Scope(int pos,
               int len)

  - ### Method Detail

    - #### getParentScope

          public Scope getParentScope()

    - #### setParentScope

          public void setParentScope(Scope parentScope)

      Sets parent scope

    - #### clearParentScope

          public void clearParentScope()

      Used only for code generation.

    - #### getChildScopes

          public java.util.List<Scope> getChildScopes()

      Return a list of the scopes whose parent is this scope.
      Returns:
        the list of scopes we enclose, or `null` if none

    - #### addChildScope

          public void addChildScope(Scope child)

      Add a scope to our list of child scopes. Sets the child's parent scope to this scope.
      Throws:
        `java.lang.IllegalStateException` - if the child's parent scope is non-`null`

    - #### replaceWith

          public void replaceWith(Scope newScope)

      Used by the parser; not intended for typical use. Changes the parent-scope links for this scope's child scopes to the specified new scope. Copies symbols from this scope into new scope.
      Parameters:
        `newScope` - the scope that will replace this one on the scope stack.

    - #### getTop

          public ScriptNode getTop()

      Returns current script or function scope

    - #### setTop

          public void setTop(ScriptNode top)

      Sets top current script or function scope

    - #### splitScope

          public static Scope splitScope(Scope scope)

      Creates a new scope node, moving symbol table information from "scope" to the new node, and making "scope" a nested scope contained by the new node. Useful for injecting a new scope in a scope chain.

    - #### joinScopes

          public static void joinScopes(Scope source,
                        Scope dest)

      Copies all symbols from source scope to dest scope.

    - #### getDefiningScope

          public Scope getDefiningScope(java.lang.String name)

      Returns the scope in which this name is defined
      Parameters:
        `name` - the symbol to look up
      Returns:
        this `Scope`, one of its parent scopes, or `null` if the name is not defined any this scope chain

    - #### getSymbol

          public Symbol getSymbol(java.lang.String name)

      Looks up a symbol in this scope.
      Parameters:
        `name` - the symbol name
      Returns:
        the Symbol, or `null` if not found

    - #### putSymbol

          public void putSymbol(Symbol symbol)

      Enters a symbol into this scope.

    - #### getSymbolTable

          public java.util.Map<java.lang.String,Symbol> getSymbolTable()

      Returns the symbol table for this scope.
      Returns:
        the symbol table. May be `null`.

    - #### setSymbolTable

          public void setSymbolTable(java.util.Map<java.lang.String,Symbol> table)

      Sets the symbol table for this scope. May be `null`.

    - #### getStatements

          public java.util.List<AstNode> getStatements()

      Returns a copy of the child list, with each child cast to an `AstNode`.
      Throws:
        `java.lang.ClassCastException` - if any non-`AstNode` objects are in the child list, e.g. if this method is called after the code generator begins the tree transformation.

    - #### toSource

          public java.lang.String toSource(int depth)

      Description copied from class: `AstNode`
      Emits source code for this node. Callee is responsible for calling this function recursively on children, incrementing indent as appropriate.

      Note: if the parser was in error-recovery mode, some AST nodes may have `null` children that are expected to be non-`null` when no errors are present. In this situation, the behavior of the `toSource` method is undefined: `toSource` implementations may assume that the AST node is error-free, since it is intended to be invoked only at runtime after a successful parse.

      Overrides:
        `toSource` in class `Jump`
      Parameters:
        `depth` - the current recursion depth, typically beginning at 0 when called on the root node.

    - #### visit

          public void visit(NodeVisitor v)

      Description copied from class: `Jump`
      Jumps are only used directly during code generation, and do not support this interface.
      Overrides:
        `visit` in class `Jump`
      Parameters:
        `v` - the object to call with this node and its children