https://dokuwiki.grogra.de/ 2026-05-16T10:24:07+00:00 https://dokuwiki.grogra.de/ https://dokuwiki.grogra.de/lib/exe/fetch.php?media=wiki:dokuwiki.svg text/html 2025-08-20T08:32:20+00:00 Anonymous (anonymous@undisclosed.example.com) https://dokuwiki.grogra.de/doku.php?id=01_user_documentation:07_rgg_xl:02_xl:08_object:04_generator:01_generator_methods&rev=1755678740&do=diff Generator Methods As generator expressions are handled by internal iterators, the declaration of generator methods, i. e., methods which return multiple values in succession, is easy. Such a method has to receive an additional argument for the consumer to which it can pass its return values one after another. text/html 2025-08-20T08:32:20+00:00 Anonymous (anonymous@undisclosed.example.com) https://dokuwiki.grogra.de/doku.php?id=01_user_documentation:07_rgg_xl:02_xl:08_object:04_generator:02_range_operator&rev=1755678740&do=diff Range Operator The expression a : b using the range operator also defines a generator expression. The range operator is defined for operand types int and long and yields the values a, a+1, . . . , b. If a > b, no value is yielded at all. Because generator expressions are allowed within an enhanced text/html 2025-08-20T08:32:20+00:00 Anonymous (anonymous@undisclosed.example.com) https://dokuwiki.grogra.de/doku.php?id=01_user_documentation:07_rgg_xl:02_xl:08_object:04_generator:03_array_generator&rev=1755678740&do=diff Array Generator The array generator a[:] is a generator expression which yields all values of the elements of the array a, starting with the element at index 0. For the purpose of for loops, there is no need for such an expression because the Java programming language already defines the syntax text/html 2025-09-04T09:25:23+00:00 Anonymous (anonymous@undisclosed.example.com) https://dokuwiki.grogra.de/doku.php?id=01_user_documentation:07_rgg_xl:02_xl:08_object:04_generator:04_guard_operator&rev=1756977923&do=diff Guard Operator The guard operator a :: b defines a generator expression which yields a if b is true and no value at all if b is false. This is especially useful if a is a generator expression itself, then the guard b filters the values yielded by a. The following generator expression yields all lowercase letters from a String s: text/html 2025-08-20T08:32:20+00:00 Anonymous (anonymous@undisclosed.example.com) https://dokuwiki.grogra.de/doku.php?id=01_user_documentation:07_rgg_xl:02_xl:08_object:04_generator:05_filter_methods&rev=1755678740&do=diff Filter Methods Filter methods are a generalization of the guard operator. Their input is a sequence of values. For each value, a filter method decides whether to yield a result or not. In contrast to the guard operator, the result may differ from the input in value or even in type.