如何在Pyke中断言一个消极的事实？

Question

假设我有事实档案:

code_in_git(a)
code_in_git(b)
code_in_git(c)
build_on_disk(a)
build_on_disk(c)

我想断言规则" if code_in_git($ branch)而不是build_on_disk($ branch),创建fact needs_build($ branch) ".我怎样才能做到这一点？

Answer 1

好吧,似乎我可以断言notany:

no_build_on_disk
    foreach
        deploy.code_in_git($branch)
        notany
            deploy.build_on_disk($branch)
    assert
        deploy.needs_build($branch)