org.apache.groovy.ast.tools

Class ExpressionUtils

java.lang.Object

org.apache.groovy.ast.tools.ExpressionUtils

public final class ExpressionUtils
extends Object

Method Summary

Modifier and Type	Method and Description
static boolean	isNullConstant(Expression expr)
static boolean	isNumberOrArrayOfNumber(ClassNode targetType, boolean recurse) Determine if a type is derived from Number (or array thereof).
static boolean	isSuperExpression(Expression expression)
static boolean	isThisExpression(Expression expression)
static boolean	isThisOrSuper(Expression expression)
static boolean	isTypeOrArrayOfType(ClassNode targetType, ClassNode type, boolean recurse) Determine if a type matches another type (or array thereof).
static ConstantExpression	transformBinaryConstantExpression(BinaryExpression be, ClassNode targetType) Turns expressions of the form ConstantExpression(40) + ConstantExpression(2) into the simplified ConstantExpression(42) at compile time.
static Expression	transformInlineConstants(Expression exp) The attribute values of annotations must be primitive, String or Enum constants.
static Expression	transformInlineConstants(Expression exp, ClassNode attrType) Converts simple expressions of constants into pre-evaluated simple constants.
static Expression	transformListOfConstants(ListExpression origList, ClassNode attrType) Given a list of constants, transform each item in the list.

Methods inherited from class java.lang.Object

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

Method Detail

transformBinaryConstantExpression

public static ConstantExpression transformBinaryConstantExpression(BinaryExpression be,
                                                                   ClassNode targetType)

Turns expressions of the form ConstantExpression(40) + ConstantExpression(2) into the simplified ConstantExpression(42) at compile time.

Parameters:

be - the binary expression

targetType - the type of the result

Returns:

the transformed expression or the original if no transformation was performed

isTypeOrArrayOfType

public static boolean isTypeOrArrayOfType(ClassNode targetType,
                                          ClassNode type,
                                          boolean recurse)

Determine if a type matches another type (or array thereof).

Parameters:

targetType - the candidate type

type - the type we are checking against

recurse - true if we can have multi-dimension arrays; should be false for annotation member types

Returns:

true if the type equals the targetType or array thereof

isNumberOrArrayOfNumber

public static boolean isNumberOrArrayOfNumber(ClassNode targetType,
                                              boolean recurse)

Determine if a type is derived from Number (or array thereof).

Parameters:

targetType - the candidate type

recurse - true if we can have multi-dimension arrays; should be false for annotation member types

Returns:

true if the type equals the targetType or array thereof

transformInlineConstants

public static Expression transformInlineConstants(Expression exp,
                                                  ClassNode attrType)

Converts simple expressions of constants into pre-evaluated simple constants. Handles:

• Property expressions - referencing constants
• Simple binary expressions - String concatenation and numeric +, -, /, *
• List expressions - list of constants
• Variable expressions - referencing constants

Parameters:

exp - the original expression

attrType - the type that the final constant should be

Returns:

the transformed type or the original if no transformation was possible

transformListOfConstants

public static Expression transformListOfConstants(ListExpression origList,
                                                  ClassNode attrType)

Given a list of constants, transform each item in the list.

Parameters:

origList - the list to transform

attrType - the target type

Returns:

the transformed list or the original if nothing was changed

transformInlineConstants

public static Expression transformInlineConstants(Expression exp)

The attribute values of annotations must be primitive, String or Enum constants. In various places, such constants can be seen during type resolution but won't be readily accessible in later phases, e.g. they might be embedded into constructor code. This method transforms constants that would appear in annotations early so they aren't lost. Subsequent processing determines whether they are valid, this method simply retains the constant value as a constant expression.

Parameters:

exp - the original expression

Returns:

the converted expression

isThisExpression

public static boolean isThisExpression(Expression expression)

isSuperExpression

public static boolean isSuperExpression(Expression expression)

isThisOrSuper

public static boolean isThisOrSuper(Expression expression)

isNullConstant

public static boolean isNullConstant(Expression expr)