Message Handling with Boolean Algebra Ben Deane / CppCon / 2024-09-16 1Alternative Title "The Unreasonable Effectiveness of Boolean Algebra in Software Design, Showing the Particular Application of of a Message Handling Library, with an Excursion into the Roots of Programming" 2Frontmatter No AI/LLM was used in the creation of this talk. Code is simplified for slides; may have some errors in this talk is about The workings of a message-handling library. How messages and the fields in them are specified. Efficiently identifying (with matchers) a message coming off the wire. The role of Boolean

. . . . . . . . . . 396 14.3 md5 —MD5 message digest algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 14.4 sha —SHA-1 message digest algorithm . . . . . . . . . . . 。如果对象 允许，该函数将删除指定的属性。例如 delattr(x, 'foobar') 等价于 del x.foobar 。 class dict(**kwarg) class dict(mapping, **kwarg) class dict(iterable, **kwarg) 创建一个新的字典。dict 对象是一个字典类。参见dict 和映射类型—dict 了解这个类。 其他容器类型，请参见内置的 must 9 The Python Library Reference, 发布 2.7.18 be a dictionary. If provided, locals can be any mapping object. 在 2.4 版更改: formerly locals was required to be a dictionary. The expression argument is

. . . . . . . . . . 396 14.3 md5 —MD5 message digest algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 14.4 sha —SHA-1 message digest algorithm . . . . . . . . . . . 。如果对象 允许，该函数将删除指定的属性。例如 delattr(x, 'foobar') 等价于 del x.foobar 。 class dict(**kwarg) class dict(mapping, **kwarg) class dict(iterable, **kwarg) 创建一个新的字典。dict 对象是一个字典类。参见dict 和映射类型—dict 了解这个类。 其他容器类型，请参见内置的 must 9 The Python Library Reference, 发布 2.7.18 be a dictionary. If provided, locals can be any mapping object. 在 2.4 版更改: formerly locals was required to be a dictionary. The expression argument is

. . . . . . . . . . 396 14.3 md5 —MD5 message digest algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 14.4 sha —SHA-1 message digest algorithm . . . . . . . . . . . 。如果对象 允许，该函数将删除指定的属性。例如 delattr(x, 'foobar') 等价于 del x.foobar 。 class dict(**kwarg) class dict(mapping, **kwarg) class dict(iterable, **kwarg) 创建一个新的字典。dict 对象是一个字典类。参见dict 和映射类型—dict 了解这个类。 其他容器类型，请参见内置的 must 9 The Python Library Reference, 发布 2.7.18 be a dictionary. If provided, locals can be any mapping object. 在 2.4 版更改: formerly locals was required to be a dictionary. The expression argument is

grand philosophy, no standards lawyering, just playing with some codeOverview • The problem • Mapping typed objects to/from bytes for messages • Overall design • Flats and access types • System structure that all of the time • “Special constraints” (There are always many ) • Maybe we need to store a message for 5 years • May require low latency • May require minimal space overhead • Read and write from Stroustrup - "Primitive" - CppCon 2020 5 First decide what you want aka Requirements analysis Message write read My needs and constraints may not be yours“Everybody does something like this” • But

。如果对象 允许，该函数将删除指定的属性。例如 delattr(x, 'foobar') 等价于 del x.foobar 。 class dict(**kwarg) class dict(mapping, **kwarg) class dict(iterable, **kwarg) 创建一个新的字典。dict 对象是一个字典类。参见dict 和映射类型—dict 了解这个类。 其他容器类型，请参见内置的list、set 类型格式化数字时，该函数在某些情况下会临时性地将 LC_CTYPE 区域设置 为 LC_NUMERIC 区域。 str.format_map(mapping) 类似于 str.format(**mapping)，不同之处在于 mapping 会被直接使用而不是复制到一个dict。 适宜使用此方法的一个例子是当 mapping 为 dict 的子类的情况： >>> class Default(dict): ... def __missing__(self 字 符 串 的 副 本， 其 中 每 个 字 符 按 给 定 的 转 换 表 进 行 映 射。 转 换 表 必 须 是 一 个 使 用 __getitem__() 来实现索引操作的对象，通常为mapping 或sequence。当以 Unicode 码位序号（整 数）为索引时，转换表对象可以做以下任何一种操作：返回 Unicode 序号或字符串，将字符映射为一个 或多个字符；返回 None，将字符

。如果对象 允许，该函数将删除指定的属性。例如 delattr(x, 'foobar') 等价于 del x.foobar 。 class dict(**kwarg) class dict(mapping, **kwarg) class dict(iterable, **kwarg) 创建一个新的字典。dict 对象是一个字典类。参见dict 和映射类型—dict 了解这个类。 其他容器类型，请参见内置的list、set 类型格式化数字时，该函数在某些情况下会临时性地将 LC_CTYPE 区域设置 为 LC_NUMERIC 区域。 str.format_map(mapping) 类似于 str.format(**mapping)，不同之处在于 mapping 会被直接使用而不是复制到一个dict。 适宜使用此方法的一个例子是当 mapping 为 dict 的子类的情况： >>> class Default(dict): ... def __missing__(self 字 符 串 的 副 本， 其 中 每 个 字 符 按 给 定 的 转 换 表 进 行 映 射。 转 换 表 必 须 是 一 个 使 用 __getitem__() 来实现索引操作的对象，通常为mapping 或sequence。当以 Unicode 码位序号（整 数）为索引时，转换表对象可以做以下任何一种操作：返回 Unicode 序号或字符串，将字符映射为一个 或多个字符；返回 None，将字符

command in, conda displays its current version: conda 24.9.3.dev1 � Note If you get an error message command not found: conda, close and reopen your terminal window and verify that you are logged into dev1 (continued from previous page) # Check whether fingerprint is correct (will output an error message otherwise) gpg --keyring /usr/share/keyrings/conda-archive-keyring.gpg --no-default-keyring -- ˓→fingerprint responds with the version number that you have installed, such as conda 4.12.0. If you get an error message, make sure of the following: • You are logged into the same user account that you used to install

command in, conda displays its current version: conda 25.1.2.dev1 � Note If you get an error message command not found: conda, close and reopen your terminal window and verify that you are logged into dev1 (continued from previous page) # Check whether fingerprint is correct (will output an error message otherwise) gpg --keyring /usr/share/keyrings/conda-archive-keyring.gpg --no-default-keyring -- ˓→fingerprint responds with the version number that you have installed, such as conda 4.12.0. If you get an error message, make sure of the following: • You are logged into the same user account that you used to install

command in, conda displays its current version: conda 24.11.3.dev2 � Note If you get an error message command not found: conda, close and reopen your terminal window and verify that you are logged into dev2 (continued from previous page) # Check whether fingerprint is correct (will output an error message otherwise) gpg --keyring /usr/share/keyrings/conda-archive-keyring.gpg --no-default-keyring -- ˓→fingerprint responds with the version number that you have installed, such as conda 4.12.0. If you get an error message, make sure of the following: • You are logged into the same user account that you used to install