com.google.gwt.dev.js

Class JsLiteralInterner

java.lang.Object

com.google.gwt.dev.js.JsLiteralInterner

public class JsLiteralInterner
extends Object

Interns conditionally either all literals in a JsProgram, or literals which exceed a certain usage count. Each unique literal will be assigned to a variable in an appropriate program fragment and the JsLiteral will be replaced with a JsNameRef. This optimization is complete in a single pass, It is not safe to run the interner multiple times on the same tree as the names that are assigned to interned literals will collide.

Field Summary

Fields

Modifier and Type	Field and Description
static byte	INTERN_ALL
static byte	INTERN_ARRAY_LITERALS Flags to control what type of literals to intern.
static byte	INTERN_NUMBERS
static byte	INTERN_OBJECT_LITERALS
static byte	INTERN_REGEXES
static byte	INTERN_STRINGS

Method Summary

Modifier and Type	Method and Description
static Map<JsName,JsLiteral>	exec(JProgram jprogram, JsProgram program, byte whatToIntern) Apply interning of literals to a JsProgram.
static boolean	exec(JsProgram program, JsBlock block, JsScope scope, boolean alwaysIntern) Intern literals that occur within a JsBlock.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, toString

Field Detail

INTERN_ARRAY_LITERALS

public static final byte INTERN_ARRAY_LITERALS

Flags to control what type of literals to intern.

See Also:

Constant Field Values

INTERN_NUMBERS

public static final byte INTERN_NUMBERS

See Also:

Constant Field Values

INTERN_OBJECT_LITERALS

public static final byte INTERN_OBJECT_LITERALS

See Also:

Constant Field Values

INTERN_REGEXES

public static final byte INTERN_REGEXES

See Also:

Constant Field Values

INTERN_STRINGS

public static final byte INTERN_STRINGS

See Also:

Constant Field Values

INTERN_ALL

public static final byte INTERN_ALL

See Also:

Constant Field Values

Method Detail

exec

public static Map<JsName,JsLiteral> exec(JProgram jprogram,
                                         JsProgram program,
                                         byte whatToIntern)

Apply interning of literals to a JsProgram. The symbol names for the interned literals will be defined within the program's top scope and the symbol declarations will be added as the first statement in the program's global block.

Parameters:

jprogram - the JProgram that has fragment dependency data for program

program - the JsProgram

whatToIntern - a byte mask indicating what types of literals are interned.

Returns:

a map describing the interning that occurred

exec

public static boolean exec(JsProgram program,
                           JsBlock block,
                           JsScope scope,
                           boolean alwaysIntern)

Intern literals that occur within a JsBlock. The symbol declarations will be added as the first statement in the block.

Parameters:

block - the block to visit.

scope - the JsScope in which to reserve the new identifiers.

alwaysIntern - whether to intern all literals regardless of their occurrence count.

Returns:

true if any changes were made to the block.