Package org.codehaus.groovy.ast.expr

Class Expression

java.lang.Object

org.codehaus.groovy.ast.ASTNode

org.codehaus.groovy.ast.AnnotatedNode

org.codehaus.groovy.ast.expr.Expression

All Implemented Interfaces:

GroovydocHolder<AnnotatedNode>, NodeMetaDataHandler

Direct Known Subclasses:

AbstractGinqExpression, ArrayExpression, BinaryExpression, BitwiseNegationExpression, BooleanExpression, BytecodeExpression, CastExpression, ClassExpression, ClosureExpression, ConstantExpression, ConstructorCallExpression, EmptyExpression, FieldExpression, GStringExpression, ListExpression, ListOfExpressionsExpression, MapEntryExpression, MapExpression, MethodCallExpression, MethodPointerExpression, PostfixExpression, PrefixExpression, PropertyExpression, RangeExpression, SpreadExpression, SpreadMapExpression, StaticMethodCallExpression, TemporaryVariableExpression, TernaryExpression, TupleExpression, UnaryMinusExpression, UnaryPlusExpression, VariableExpression

public abstract class Expression
extends AnnotatedNode

Base class for all expression nodes in the Groovy AST. Expressions represent values and computations that can be evaluated at runtime, supporting type information and transformation operations. All concrete expression types inherit from this abstract class and must implement the transformExpression(ExpressionTransformer) method for AST transformation support.

See Also:

• Statement
• ExpressionTransformer
• GroovyCodeVisitor

Field Summary

Fields

Modifier and Type	Field	Description
static final Expression[]	EMPTY_ARRAY

Fields inherited from interface groovy.lang.groovydoc.GroovydocHolder

DOC_COMMENT

Constructor Summary

Constructors

Constructor	Description
Expression()

Method Summary

Modifier and Type	Method	Description
ClassNode	getType()	Returns the type of this expression.
void	setType(ClassNode type)	Sets the type information for this expression.
abstract Expression	transformExpression(ExpressionTransformer transformer)	Transforms this expression and any nested expressions according to the provided transformer.
protected List<Expression>	transformExpressions(List<? extends Expression> expressions, ExpressionTransformer transformer)	Transforms a list of expressions by applying the provided transformer to each element.
protected <T extends Expression> List<T>	transformExpressions(List<? extends Expression> expressions, ExpressionTransformer transformer, Class<T> targetType)	Transforms a list of expressions and verifies that all transformed expressions have a specific type.

Methods inherited from class org.codehaus.groovy.ast.AnnotatedNode

addAnnotation, addAnnotation, addAnnotations, getAnnotations, getAnnotations, getDeclaringClass, getGroovydoc, getInstance, hasNoRealSourcePosition, isSynthetic, setDeclaringClass, setHasNoRealSourcePosition, setSynthetic

Methods inherited from class org.codehaus.groovy.ast.ASTNode

copyNodeMetaData, getColumnNumber, getLastColumnNumber, getLastLineNumber, getLineNumber, getMetaDataMap, getText, setColumnNumber, setLastColumnNumber, setLastLineNumber, setLineNumber, setMetaDataMap, setSourcePosition, visit

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.codehaus.groovy.ast.NodeMetaDataHandler

copyNodeMetaData, getNodeMetaData, getNodeMetaData, getNodeMetaData, newMetaDataMap, putNodeMetaData, removeNodeMetaData, setNodeMetaData

Field Details

EMPTY_ARRAY

public static final Expression[] EMPTY_ARRAY

Constructor Details

Expression

public Expression()

Method Details

getType

public ClassNode getType()

Returns the type of this expression. If the type has not been explicitly set, this method returns a dynamic type to support dynamic typing.

Returns:

the ClassNode representing this expression's type

setType

public void setType(ClassNode type)

Sets the type information for this expression. Used during type checking and compilation phases to associate a specific type with this expression result.

Parameters:

type - the ClassNode representing this expression's type

transformExpression

public abstract Expression transformExpression(ExpressionTransformer transformer)

Transforms this expression and any nested expressions according to the provided transformer. This method is called during AST transformation phases and must recursively transform any nested expressions to support full AST tree transformation.

Parameters:

transformer - the ExpressionTransformer to apply

Returns:

a transformed copy of this expression (or this expression itself if no changes are needed)

transformExpressions

protected List<Expression> transformExpressions(List<? extends Expression> expressions,
 ExpressionTransformer transformer)

Transforms a list of expressions by applying the provided transformer to each element. Handles null expressions gracefully by including them in the result.

Parameters:

expressions - the list of Expressions to transform

transformer - the ExpressionTransformer to apply

Returns:

a new list containing transformed expressions

transformExpressions

protected <T extends Expression> List<T> transformExpressions(List<? extends Expression> expressions,
 ExpressionTransformer transformer,
 Class<T> targetType)

Transforms a list of expressions and verifies that all transformed expressions have a specific type. This variant provides type safety during transformations by enforcing that transformed expressions conform to a target type. Throws GroovyBugError if any expression has an incompatible type.

Type Parameters:

T - the target expression type parameter

Parameters:

expressions - the list of Expressions to transform

transformer - the ExpressionTransformer to apply

targetType - the expected type of all transformed expressions

Returns:

a new type-safe list of transformed expressions

Throws:

GroovyBugError - if any transformed expression is not an instance of targetType