issue271: 26.3. Abstract Syntax Trees (AST) - yield expression should be optional. (#272)
issue271: 26.3. Abstract Syntax Trees (AST) - yield expression should be optional. (#272)


jeff5/jython-devguide,jython/devguide,jython/devguide,jeff5/jython-devguide,jeff5/jython-devguide,jython/devguide,ezio-melotti/devguide