There are links out in the wild to the old XML style guide. An XML file that links to the new style guide location ensures that those links are not completely broken.
- Change formatting rules of braced initializers.
- Permit use of constexpr and allow constexpr global variables.
- Allow all C++11 features except for those that are specifically banned.
- Fix/add C99 format specifiers for ptrdiff_t and ssize_t.
- Add lambda expressions to the list of explicitly banned C++11 features.
- Relax "return type is always on the same line as the function name" rule.
- Allow unique_ptr, discourage ownership transfer. Allow noncopyable std::move.
- Allow system-specific includes after other includes.
- Add boost/math/distributions to the set of permitted Boost libraries.
Update Objective-C style guide to 2.59:
- Use instancetype as return type for example init methods.
- Remove invalid +stringWithInt: call.
- Remove reference to pre-Objective-C 2.0 declaration requirements.
- Remove reference to Objective-C exception macros.
- Remove reference to informal protocols as an alternative to optional methods.
- Class headers should include comments documenting non-trivial interfaces.
- Don't specify that blocks are preferable to methods as callbacks.
- Specify "strong" and "weak" as comments for non-Objective-C pointers.
- Replace improper reference to ownership of a retained object.
- Clarify some aspects of method ordering rules.
- Prefixes are required for shared code and optional for applications.
- Clarify that nil pointers are safe as receivers, not necessarily parameters.
- Clarify that delegate pointers should typically be zeroing weak pointers.
- Allow a 100-column limit, except for projects that choose to use 80.
Update Python style guide to 2.59:
- Add more examples of bad code to the default arguments section.
- Allow ''' when ' is used as the single quote within a file.
- Remove references to pychecker. Recommend pylint.
- Add more examples to the indentation section.
Update JavaScript style guide to 2.93:
- Add @nocompile.
- Fix a few typos.
- When wrapping lines, indent more deeply for child expressions.
- Document that @const can be used on a constructor.
- Update eval section to discourage using eval for RPC.
- Update an example to avoid encouraging using numbers as booleans.
- Allow for no indentation of @desc jsdoc tags.
- Add @public discussion.
Update shell style guide to 1.26:
- Add a section on style for case statements.
Update Common Lisp style guide to 1.23:
- fare-matcher was superseded by optima.
- Clarify wording regarding DYNAMIC-EXTENT.
- Add boost::bimap to the list of allowed Boost libraries.
- C++11: remove mention of constexpr.
- Remove noun/verb naming rules, and consolidate "General Naming Rules".
- C++11: allow variadic templates.
- Revise guidance on function definition comments.
- Clarify that one space is sufficient before trailing /* */ comments.
- C++11: allow alias templates.
- C++11: allow <array>, deprecate Boost array.
- C++11: allow unique_ptr, deprecate Boost pointer container.
- C++11: allow braced initializer lists.
Update Objective-C style guide to 2.56:
- Add details on constant declarations to clarify naming and scope issues.
- Update link to Apple's Objective-C guide.
- Allow left-aligning multi-block method invocation segments.
- Add section on container literals.
Update Python style guide to 2.54:
- Allow str.format in addition to the % operator.
- Allow #!/usr/bin/python2 and #!/usr/bin/python3.
- Move the closing brace example from column 4 to 0.
- Remove the requirement to use named parameters for arguments with defaults.
Update HTML/CSS style guide to 2.23:
- No changes.
Update JavaScript style guide to 2.82:
- Fix typos, whitespace, and character entities.
- Include property descriptions in the clause about omitting obvious comments.
- Make file overviews optional.
- Fix example in "HTML in JSDoc" section.
- Remove the semicolon-insertion language from the operators section.
- State that complete sentences are recommended but not required.
- Document usage of goog.scope to declare new classes.
Update Common Lisp style guide to 1.20:
- Indicate both variable and function predicates require a "p".
- Make the abbreviations rules consistent and in one location.
- Don't allow for the use of &AUX.
- Allow for "body" and "end" as exceptions to the suffix rule.
- Use the TODO convention to mark code that needs to be addressed.
- Remove file maintainership requirements, require a description.
- Change top-level form requirements to the length of a page.
- Remove "don't be clever".
- Relax the rule for sizeof(varname) vs. sizeof(type).
- Allow an exception for nonconst reference parameters where
convention dictates their use, such as for swap.
- C++11: allow static_assert.
- Require non-trivial fall-through between cases in switch
statements to be annotated. Trivial fall-through includes
consecutive case labels with no intervening code, and no comment
is required in these cases.
- C++11: allow constexpr.
- Revise the "Integer Types" section to note type-width problems.
- Clarify that the "arguments on subsequent lines" function call
style is acceptable even when the 80-column limit doesn't require
it.
- Boost: allow part of Polygon.
- C++11: allow <tuple>.
Update Objective-C style guide to 2.52:
- Fix ARC example to not imply the use of @private in .m files.
- Add an example to the "Category Names" section.
- Require that ARC-using files insert preprocessor directives that
generate an error when compiling without ARC.
- Fix spacing around the *s in the ARC example per the C++ style
guide.
Update Python style guide to 2.48:
- Allow comments with URLs to exceed 80 characters per line.
- Update outdated implicit-line-joining URLs.
Update HTML/CSS style guide to 2.21:
- Consistent use of title case.
- Add new "Declaration Block Separation" section.
- Add a CSS example to the "Capitalization" section.
- Minor fixes to whitespace.
Update JavaScript style to guide to 2.72:
- Make it clear that the injunction against aliasing namespaces only
applies to local aliases, not goog.scope.
- Clarify the style guide's recommendation on array/object literals.
- Add documentation on @private {type}, @protected {type}, and
@const {type}.
- Make JSDoc descriptions required only if not obvious.
- Clarify that only private properties and methods need a trailing
underscore.
- Fix spelling of arv's name.
Update Common Lisp style guide to 1.18:
- Macro-defining macros are harder to understand for everyone, not
just for the "uninitiated." There's no need to condescend.
In all of the above style guides:
- The guide source is now encoded as UTF-8. The numeric character
references have been replaced with raw UTF-8-encoded characters.
- Clarify that sentence-like non-sentence comments are permitted.
- Note that older code with incorrect #include ordering should be fixed.
- Revamp the section on default function arguments.
- Avoid explicitly recommending Init() methods.
- C++11: permit "auto".
- C++11: permit ">>" in place of "> >".
- C++11: permit range-based "for".
- C++11: permit variadic macros (already permitted as a C++03 extension).
- C++11: permit "LL" and "ULL" literal suffixes (already permitted as a C++03
extension).
- Reflect the revised copyright and author line policy: copyright notices are
not required, but license boilerplate may still be used (and generally
contains a copyright notice). Author lines are not required.
- C++11: permit new features in <algorithm> and the portion of <numeric> that
does not require initializer lists.
- Revise rules on forward declarations: explicitly forbid forward-declared
functions, do not mandate forward declarations, discourage forward-declared
templates.
- Remove the rule requiring "const" qualifiers for member functions to be
on the same line as the closing parenthesis of the parameter list.
- Fix typo: "unnamed namespaces."
- C++11: permit local types as template parameters.
- Fix typo: "unfamiliar."
- Relax RTTI rules to permit its use, but warn about its abuse.
- C++11: permit nullptr and nullptr_t. Revise text referring to NULL to refer
more generically to null pointers.
- Remove the "don't go crazy with const" rule.
- Fix typo: "dir/foo2" should bee "dir2/foo2."
- Remove reference to a specific GCC version.
Update Objective-C style guide to 2.48:
- Revise method declaration and invocation formatting rules for long names.
- Reflect the revised copyright and author line policy: copyright notices are
not required, but license boilerplate may still be used (and generally
contains a copyright notice). Author lines are not required. Top-of-file
comments are not required.
- Fix dead link in the "nil Checks" section.
- Cover ARC.
- Specify that @private is only required for instance variables in header
files.
- Permit NSNumber literals.
- Change the naming convention for instance variables from trailing underscore
to leading underscore, allowing a wide exception for existing code and
projects.
- Fix description of BOOL with respect to its signedness.
Update Python style guide to 2.45:
- Recommend "pylint: disable" over "pylint: disable-msg."
- Fix case-sensitive anchor.
- Provide a better explanation of the problems with catch-all "except:."
- Permit "map" and "filter" in absence of inlined lambdas.
Update JavaScript style guide to 2.64:
- Clarify rules for requiring and providing inner dependencies on classes.
- Clarify semicolons for functions.
- Note proper namespace and filename casing.
- Fix typos: "@extends."
- Permit parentheses to be omitted on unions.
- Don't require method descriptions when obvious.
- "in" is a keyword, put it in <code>.
- New "Aliasing with goog.scope" section.
- Rewrite the "Constants" section.
- Remove the recommendation to use join() to build strings.
- Add the "@expose" annotation.
- Fix the "@suppress" example.
- Remove reference alternate cast syntax.
- Reflect the revised copyright and author line policy: copyright notices are
not required, but license boilerplate may still be used (and generally
contains a copyright notice). Author lines are not required.
- Say that "use strict" is not required.
- Fix links to "optional" section.
- Rewrite "JavaScript Types" section.
- Fix typos: "parameterizes," "converted."
- Prefer in-constructor field initialization.
- Add a section on "delete" and null-assignment.
- Add a note about optional JSDoc comments on enum values.
- State explicitly that dot operators belong at the ends of lines.
- Add "@dict" and "@struct" annotations.
- Add links to the JavaScript Types section.
- Require (rather than encourage) compiling.
Update HTML/CSS style guide to 2.19:
- Rephrased quotation guidelines.
- Updated W3C I18N article reference.
- Fixed revision number.
Update styleguide.xsl to 1.34:
- Fix error in RefreshVisibilityFromHashParam when a URL fragment points to a
named anchor within a section, as used by the JavaScript style guide.
- Update an example to omit the blank line between C and C++ #includes.
- Rewrite the paragraph about #include ordering.
- Clarify namespace closing comments.
- Discourage const references for input arguments which are aliased beyond
the scope of the function call.
- Replace all '&' with '&'.
- Clarify that interfaces must have virtual destructors.
- Add an explicit example for |else if|.
- C++11 updates.
Update Objective-C style guide to 2.36:
- Remove requirement to list @dynamic implementations.
- Remove requirement to never synthesize CFType properties, since they may
be retained on 10.6.
- Use __weak and __strong type declaration modifiers rather than comments.
- Make the copyright/license information consistent.
- An example initializer comment revealed too much about the implementation.
- Correct spelling mistakes.
- Fix names that didn't follow Cocoa conventions.
- Fix examples to conform to style.
- Add a section about no braces for empty interfaces.
- Add a section about automatically synthesized instance variables.
- Codify avoidance of accessors in -init and -dealloc methods.
- Changes for the 80-column rule.
- Weaken the language around object ownership type qualifiers.
- Document the rules for formatting blocks.
Update JavaScript style guide to 2.27:
- Introduce EcmaScript 5 Strict verbiage.
- Add a note about private constructors.
- Simplify explanations about JSDoc comments.
- Sort the JSDoc tags.
- Remove the sections about type-checking now that the JSDoc tags and JS
types are no longer one table.
- Convert <tt> to <code>, because the XSL processor eats <tt>.
- Add @suppress.
- Mark @inheritDoc deprecated in favor of @override.
- Add a section about inner classes and enums being defined in the same file
as the top-level class they are defined on.
Update Python style guide to 2.28:
- Change "Naming" summary to match body.
- Make the prohibition against backslash line continuation explicit.
- Update the TODO section to match the C++ style guide.
- Declare Python code without a shebang line to be stylish.
- Clarify rules on function docstrings.
- Fix spelling errors.
- Update with styleguide.xsl 1.33.
Update styleguide.xsl to 1.33:
- Clean up style guide JS.
- Links to anchor tags auto-expand.
- Revise "Smart Pointers" section.
- Clarify that it's OK to have spaces after '#' in a preprocessor directive,
even though '#' itself must not be indented.
- Revise "TODO Comments" section.
- Fix wording.
- Explicitly recommend foo.h be the first file #included by foo_test.cc.
Update Objective-C style guide to 2.24:
- Clarify the spacing of @property declarations.
- Add "Overridden NSObject Method Placement" section.
- Explicitly permit blank lines around @interface, @implementation, and @end.
Update JavaScript style guide to 2.20:
- Provide additional guidance with respect to the compiler.
- Add {function(new:Type)} as a type syntax for constructors of Type.
- Revise "Method and Function Comments" section.
- Harmonize text and example in the "Passing Anonymous Functions" section.
- Explicitly state that @param and @return types must be enclosed in braces.
- Add documentation on the UNKNOWN type.
- Replace a CODE_SNIPPET with BAD_CODE_SNIPPET in the "Internet Explorer's
Conditional Comments" section.
- Remove a redundant "Expand for more information" in the "Naming" section
and fully spell out "information" in the "Code Formatting" section.
- Provide a positive example in the "Multiline string literals" section.
- Provide guidance for indentation within nested functions.
Update Python style guide to 2.20:
- Clarify shebang rule.
- Add leading blank line exception.
- Improve guidance for function definition comments.
- Tweak class comment example to not violate type naming guidelines.
Update Objective-C style guide to 2.21:
- Prohibit +new.
Update JavaScript style guide to 2.9:
- Add new "Function Declarations Within Blocks" section.
- Add new "Internet Explorer's Conditional Comments" section.
- Add new "Alias long type names to improve readability" section.
- Add @lends.
- Forbid the use of operator synonyms such as "and."
- Specify the naming convention (OrDie) to use when a function has
crash-on-failure semantics.
- Allow static const data members to be non-private.
- Specify placement of friend declarations.
- Require each file to include headers that they use.
Update Objective-C style guide to 2.18:
- Prefer @optional to informal protocols when possible.
- Specify formatting for invoking methods.
- Require that -dealloc be easy to review.
- Make the messaging on DISALLOW_EVIL_CONSTRUCTORS more clear that we should
not be rewriting old code but should simply prefer DISALLOW_COPY_AND_ASSIGN
on new code.
- s/Initializer Lists/Constructor Initializer Lists/ since people search for
this based on knowing it's part of the constructor, but forget the precise
name.
- Allow data members in a test fixture to be private.
- Loosen restrictions on globals.
- Add explicit guideline for nested namespace formatting.
- Strengthen the prohibition against operator overloading for operator&.
- Add recommendation for "_" over "-" in file names.
- Revise the "Copy Constructors" section for brevity and clarity. Emphasize
preference for standard over nonstandard copy operations.
- Weaken the wording at the top of the "Doing Work in Constructors" section,
making it clear that Init() methods are not absolutely required for
non-trivial initialization.
- Fix minor typos and grammatical errors.
Update Objective-C style guide to 2.14:
- Add the Rule of Four for indenting parameters. Allow either of two forms
for formatting methods with short first keywords.
- Update the guidance on BOOL vs. bool.
- Whitespace cleanup.
Update Python style guide to 2.14:
- Consolidate discussion of the string module, apply, map, filter, and reduce
into a single section.
- Make it explicit that functions and classes can be nested inside methods.
- Clarify that a "very strong convention" is, in fact, only very strong
within Google code
- Update the style guide with an additional naming possibility for enums:
kEnumName
- Reword the summary for the section on header file dependencies
- Simplify wording regarding static variables
Update Objective-C style guide to 2.11:
- Provide guidance on when to use #import and #include
- Display revision in style guide
Update styleguide.xsl with a hint of things to come
Set svn:eol-style on xmlstyle.html
- Change list of permitted Boost libraries
- Permit one space before // in a new {scope}
- Grammar fix!
Update Objective-C style guide:
- Link spacing changes only
Ted Osborne
Google Python team
Stephane Moore
Kevin Lindkvist
Ackermann Yuriy
mark@chromium.org
mmentovai
pinkerton