有没有办法在新行上拆分逻辑条件？

Posted 2023-02-21

【中文标题】有没有办法在新行上拆分逻辑条件？

【英文标题】：Is there a way to split logical conditions on new lines?

【发布时间】：2021-11-15 01:25:46

【问题描述】：

例如，我希望我的行长为 120 - 所以通常代码仅在 120 个字符后包装。但更常见的情况是，我们不希望将逻辑条件放在新行上：

我有以下表达：

    if ((long_function_name_12345().get_some_status1() != status1) ||
        (long_function_name_12345().get_some_status2() != status2) || 
        force || 
        some_other_logical_bool)
    
    

当我将它格式化时，我得到：

    if ((long_function_name_12345().get_some_status1() != status1) ||
        (long_function_name_12345().get_some_status2() != status2) || force || some_other_logical_bool)
    
    

这不是那么好。我希望行为是，一旦我们超过列限制（在本例中为 120），然后在任何逻辑块上中断。我找到了一种强制方法：

    if ((long_function_name_12345().get_some_status1() != status1) ||
        (long_function_name_12345().get_some_status2() != status2) || // break
        force || // break
        some_other_logical_bool)
    
    

这有点废话，但有效，但（IMO）不那么丑陋，然后将其包装在 // clang-format off/on 标签中......

clang 格式版本 10.0.0-4ubuntu1~18.04.2

.clang 格式的内容：

---
Language:        Cpp
# BasedOnStyle:  WebKit
AccessModifierOffset: -4
AlignAfterOpenBracket: AlwaysBreak
AlignConsecutiveMacros: false
AlignConsecutiveAssignments: false
AlignConsecutiveDeclarations: false
AlignEscapedNewlines: Right
AlignOperands:   false
AlignTrailingComments: false
AllowAllArgumentsOnNextLine: false
AllowAllConstructorInitializersOnNextLine: false
AllowAllParametersOfDeclarationOnNextLine: false
AllowShortBlocksOnASingleLine: false
AllowShortCaseLabelsOnASingleLine: false
# Don't allow function on one line, e.g. 'int f() return 1;' - unless its inline
AllowShortFunctionsOnASingleLine: InlineOnly
AllowShortLambdasOnASingleLine: All
AllowShortIfStatementsOnASingleLine: Never
AllowShortLoopsOnASingleLine: false
AlwaysBreakAfterDefinitionReturnType: None
AlwaysBreakAfterReturnType: None
AlwaysBreakBeforeMultilineStrings: false
AlwaysBreakTemplateDeclarations: MultiLine
BinPackArguments: false
BinPackParameters: false
BraceWrapping:
  AfterCaseLabel:  true
  AfterClass:      true
  AfterControlStatement: true
  AfterEnum:       true
  AfterFunction:   true
  AfterNamespace:  true
  AfterObjCDeclaration: true
  AfterStruct:     true
  AfterUnion:      true
  AfterExternBlock: true
  BeforeCatch:     true
  BeforeElse:      true
  IndentBraces:    true
  SplitEmptyFunction: true
  SplitEmptyRecord: true
  SplitEmptyNamespace: true
# have line breaks after operators: 'if (a ||' instead of on the next line ' || b'
BreakBeforeBinaryOperators: None
BreakBeforeBraces: Allman
BreakBeforeInheritanceComma: false
BreakInheritanceList: BeforeColon
BreakBeforeTernaryOperators: true
BreakConstructorInitializersBeforeComma: false
BreakConstructorInitializers: BeforeComma
BreakAfterJavaFieldAnnotations: false
BreakStringLiterals: true
# effectively the line length limit before clang-format starts to use multiple lines
ColumnLimit:     120
CommentPragmas:  '^ IWYU pragma:'
CompactNamespaces: false
ConstructorInitializerAllOnOneLineOrOnePerLine: false
ConstructorInitializerIndentWidth: 4
ContinuationIndentWidth: 4
# format braces lists (uniform init) like a function param list
Cpp11BracedListStyle: true
DeriveLineEnding: true
DerivePointerAlignment: false
DisableFormat:   false
ExperimentalAutoDetectBinPacking: false
FixNamespaceComments: false
ForEachMacros:
  - foreach
  - Q_FOREACH
  - BOOST_FOREACH
IncludeBlocks:   Preserve
IncludeCategories:
  - Regex:           '^"(llvm|llvm-c|clang|clang-c)/'
Priority:        2
SortPriority:    0
  - Regex:           '^(<|"(gtest|gmock|isl|json)/)'
Priority:        3
SortPriority:    0
  - Regex:           '.*'
Priority:        1
SortPriority:    0
IncludeIsMainRegex: '(Test)?$'
IncludeIsMainSourceRegex: ''
IndentCaseLabels: true
IndentGotoLabels: true
IndentPPDirectives: None
IndentWidth:     4
IndentWrappedFunctionNames: false
javascriptQuotes: Leave
JavaScriptWrapImports: true
KeepEmptyLinesAtTheStartOfBlocks: true
MacroBlockBegin: ''
MacroBlockEnd:   ''
MaxEmptyLinesToKeep: 1
NamespaceIndentation: Inner
ObjCBinPackProtocolList: Auto
ObjCBlockIndentWidth: 4
ObjCSpaceAfterProperty: true
ObjCSpaceBeforeProtocolList: true
PenaltyBreakAssignment: 2
PenaltyBreakBeforeFirstCallParameter: 19
PenaltyBreakComment: 300
PenaltyBreakFirstLessLess: 120
PenaltyBreakString: 1000
PenaltyBreakTemplateDeclaration: 10
PenaltyExcessCharacter: 1000000
PenaltyReturnTypeOnItsOwnLine: 60
# 'int *p' instead of 'int* p;'
PointerAlignment: Right
ReflowComments:  true
SortIncludes:    true
SortUsingDeclarations: true
SpaceAfterCStyleCast: false
SpaceAfterLogicalNot: false
SpaceAfterTemplateKeyword: true
SpaceBeforeAssignmentOperators: true
SpaceBeforeCpp11BracedList: true
SpaceBeforeCtorInitializerColon: true
SpaceBeforeInheritanceColon: true
SpaceBeforeParens: ControlStatements
SpaceBeforeRangeBasedForLoopColon: true
SpaceInEmptyBlock: true
SpaceInEmptyParentheses: false
SpacesBeforeTrailingComments: 1
SpacesInAngles:  false
SpacesInConditionalStatement: false
SpacesInContainerLiterals: true
SpacesInCStyleCastParentheses: false
SpacesInParentheses: false
SpacesInSquareBrackets: false
SpaceBeforeSquareBrackets: false
Standard:        Latest
StatementMacros:
  - Q_UNUSED
  - QT_REQUIRE_VERSION
TabWidth:        8
UseCRLF:         false
UseTab:          Never
...

我找不到任何明显的东西 - 也许它有点太具体了。

【问题讨论】：

个人意见，但多行ifs 经常是代码气味...如果您的条件如此庞大，它不适合 120 列 if，也许值得将它移到它的自己的函数，有一个正确的名字。

@m88 我认为这是一个没有达到 120 字符限制的行的示例，但仍应包装

@m88 4630....数字是正确的 - 如果行（完全像示例）不是 120 个字符长，我想强制更短。如果 if 语句超过 120 个字符（可能会发生在具有几个命​​名空间深度的长变量名中）。

【参考方案1】：

这是我能找到/想出的最好的（如我更新的问题中所述）：

    if ((long_function_name_12345().get_some_status1() != status1) ||
        (long_function_name_12345().get_some_status2() != status2) || // break
        force || // break
        some_other_logical_bool)
    
    

即通过添加某种注释，它会强制 clangformat 不合并行

【讨论】：

空评论有同样的效果吗？ “break”这个词在 C 和 C++ 中具有超载的含义，使其成为一个不适用的令人困惑的评论。 （免责声明：我没有使用过该工具，虽然它看起来不错。）

是的，但我认为人们可能会删除空的//，认为它是错误留下的。也许// clangfmt 之类的会更好:)