Package org.apache.groovy.contracts.ast

Class LoopInvariantASTTransformation

java.lang.Object
org.apache.groovy.contracts.ast.LoopInvariantASTTransformation
All Implemented Interfaces:
ASTTransformation
public class LoopInvariantASTTransformation extends Object implements ASTTransformation
Handles Invariant annotations placed on loop statements (for, while, do-while). The invariant closure is evaluated as an assertion at the start of each loop iteration.

When @Invariant is placed on a class (its original usage), this transform returns immediately, letting the existing global contract pipeline handle it.

Example: 

 int sum = 0
 @Invariant({ 0 <= i && i <= 4 })
 for (int i in 0..4) {
     sum += i
 }
Since:
6.0.0
See Also:

  • Constructor Details

    • LoopInvariantASTTransformation

      public LoopInvariantASTTransformation()

  • Method Details

    • visit

      public void visit(ASTNode[] nodes, SourceUnit source)
      Description copied from interface: ASTTransformation
      The method is invoked when an AST Transformation is active. For local transformations, it is invoked once each time the local annotation is encountered. For global transformations, it is invoked once for every source unit, which is typically a source file.
      Specified by:
      visit in interface ASTTransformation
      Parameters:
      nodes - The ASTnodes when the call was triggered. Element 0 is the AnnotationNode that triggered this annotation to be activated. Element 1 is the AnnotatedNode decorated, such as a MethodNode or ClassNode. For global transformations it is usually safe to ignore this parameter.
      source - The source unit being compiled. The source unit may contain several classes. For global transformations, information about the AST can be retrieved from this object.