com.google.javascript.jscomp

Class ConstCheck

java.lang.Object

com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback

com.google.javascript.jscomp.ConstCheck

All Implemented Interfaces:

CompilerPass, NodeTraversal.Callback

class ConstCheck
extends NodeTraversal.AbstractPostOrderCallback
implements CompilerPass

Verifies that constants are only assigned a value once. e.g. var XX = 5; XX = 3; // error! XX++; // error!

Field Summary

Fields

Modifier and Type	Field and Description
private AbstractCompiler	compiler
(package private) static DiagnosticType	CONST_REASSIGNED_VALUE_ERROR
private java.util.Set<Var>	initializedConstants

Constructor Summary

Constructors

Constructor and Description
ConstCheck(AbstractCompiler compiler) Creates an instance.

Method Summary

Modifier and Type	Method and Description
private static boolean	isConstant(Var var) Gets whether a variable is a constant initialized to a literal value at the point where it is declared.
void	process(Node externs, Node root) Process the JS with root node root.
(package private) void	reportError(NodeTraversal t, Node n, Var var, java.lang.String name) Reports a reassigned constant error.
void	visit(NodeTraversal t, Node n, Node parent) Visits a node in postorder (after its children have been visited).

Methods inherited from class com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback

shouldTraverse

Methods inherited from class java.lang.Object

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

Field Detail

CONST_REASSIGNED_VALUE_ERROR

static final DiagnosticType CONST_REASSIGNED_VALUE_ERROR

compiler

private final AbstractCompiler compiler

initializedConstants

private final java.util.Set<Var> initializedConstants

Constructor Detail

ConstCheck

public ConstCheck(AbstractCompiler compiler)

Creates an instance.

Method Detail

process

public void process(Node externs,
                    Node root)

Description copied from interface: CompilerPass

Process the JS with root node root. Can modify the contents of each Node tree

Specified by:

process in interface CompilerPass

Parameters:

externs - Top of external JS tree

root - Top of JS tree

visit

public void visit(NodeTraversal t,
                  Node n,
                  Node parent)

Description copied from interface: NodeTraversal.Callback

Visits a node in postorder (after its children have been visited). A node is visited only if all its parents should be traversed (NodeTraversal.Callback.shouldTraverse(NodeTraversal, Node, Node)).

Implementations can have side effects (e.g. modifying the parse tree).

Specified by:

visit in interface NodeTraversal.Callback

isConstant

private static boolean isConstant(Var var)

Gets whether a variable is a constant initialized to a literal value at the point where it is declared.

reportError

void reportError(NodeTraversal t,
                 Node n,
                 Var var,
                 java.lang.String name)

Reports a reassigned constant error.