Perl 5 中的父级和基级有什么区别？
There appears to be a new pragma named parent that does roughly the same thing as base. What does parent do that warrants a new (non-core) module? I am missing something?
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base试图做太多的事情——自动处理加载模块，但也允许从已加载的类（可能是从名称不基于模块名称的文件）建立继承。 为了让它发挥作用，一些黑客行为在某些情况下导致了令人惊讶的结果。 引入了一个具有更清晰语义的新的替换 pragmaparent，而不是破坏向后兼容性。自 5.10.1 起，
parent将成为核心模块。更新：忘记
base处理fields（如果您使用fieldspragma），它的parent不行。basetried to do one too many things – automatically handling loading modules but also allowing establishing inheritance from classes already loaded (possibly from a file whose name wasn't based on the module name). To sort of make it work, there was some hackery that caused surprising results in some cases. Rather than break backwards compatibility, a new, replacement pragmaparentwas introduced with cleaner semantics.parentwill be a core module as of 5.10.1.Update: forgot that
basehandlesfields(if you are using thefieldspragma), whichparentdoesn't do.有了来自 ysth 的额外信息，我能够看到文档中的差异：
basepragma 执行以下操作：@ISArequire（除非它检测到包已经被加载）$VERSION，则将其设置为"-1，设置方式为base.pm"字段包（如果存在）parentpragma 执行以下操作：@ISArequire加载与命名包同名的模块Armed with the extra bit of information from ysth, I was able to see the differences in the docs:
The
basepragma does the following things:@ISArequire(unless it detects that the package has already been loaded)$VERSIONdoes not exist in named package, base sets it to"-1, set by base.pm"fieldsof the named package if they existThe
parentpragma does the following things:@ISArequire