Syntax conventions

Style should be also applied also

C++

Style

• Use Clang-format
  • Download the tool according your system
    https://releases.llvm.org/
  • Install client extension
    CLang-Format from Xaver Hellauer
  • Define the style
    set Google as default style

General

• Avoid abreviation as much as possible
• Avoid unnecessary long name
• ESP3D is always uppercase in code, esp3d is valid only for filename, any mixing case is proscribed (e.g.:Esp3D/esp3D/Esp3d)
• ESP command is always uppercase, so any reference to it (e.g.: ESP100) should be uppercase to avoid confusion, only filename can be lowercase, any mixing case is proscribed

File name

• Use lower case for file names
• Use underscores as words separators
  e.g: esp3d_settings.cpp

Directory name

• Use lower case for directory names
• Use underscores as words separators
  e.g: esp3d_commansds
• Target directories are the only names that use full uppercase unlike others directories
  e.g: ESP32S3_ZX3D50CE02S_USRC_4832

Variable

• Any name should begin with an alphabet.
• The first character should be lowercase.
• Use upper case letters as words separators
• Digits may be used in the name but only after the alphabet.
• No special symbols can be used in names.
• No keywords can be used as names.
• Pointer variables should be prepended with ‘p’ and place the asterisk ‘*’ close to the name instead of the pointer type.
• Static variables should be prepended with ‘s’.
• always initialize the variable
  e.g:
  char adminPassword[20]{0};
char *pAdminLogin = nullptr;

Constant

• Any name should begin with an alphabet.
• The first character should be k.
• Use upper case letters as words separators
• Digits may be used in the name but only after the alphabet.
• No special symbols can be used in names.
• No keywords can be used as names.
  e.g: const int kTopLimit 100;

Define

Define use uppercase letters only and underscores as words separators, dash is not allowed.
e.g: #define LOWER_LIMIT 10;

Enum

• Enum should use enum class not plain enum neither enum struct
• If enum is used by several file, enum should be defined in separate file to avoid repeated definitions, and add _type suffix to file name
• The first character in the enum name must be in upper case.
• Use upper case letters as word separators.
• No underscores (‘_’) are permitted in the enum name.
• Enum values are lower case and use underscores as words separators.
• No need to typedef enum
• Use type as much as possible to clarify any casting if necessary
• Define enum values as much as possible to ensure consistency when doing update
• Do not use #ifdef in enum unless all enum values are explicitly defined

e.g: esp3d_gcode_host_type.h

• not explicitly defined

enum class Esp3dGcodeHostWait : uint8_t {
    no_wait = 0,
    wait_ack,
    wait_busy,
    wait_processing,
    wait_heating
};

Usage example: Esp3dGcodeHostWait::no_wait

• explicitly defined

enum class Status: char
{
    high = 'h',
    low = 'l'
}; 

Usage example: Status::low

Struct/Union

• If struct/union is used by several file, struct should be defined in separate file to avoid repeated definitions, and add _type suffix to file name
• The first character in the struct name must be in upper case.
• Use upper case letters as word separators
• Struct values are lower case and use underscores as words separators if variables.
• No need to typedef for struct
• As we use C++20, initialize struct explicitly

e.g: setting_description_type.h

struct  SettingDescription{
    uint16_t size = 0;
    const char* defaultVal = nullptr;
} ;

usage example: SettingDescription notificationSetting;

Class

• The class name should be a noun.
• Use upper case letters as word separators, and lower case for the rest of the word in the class name.
• The first character in the class name must be in upper case.
• No underscores (‘_’) are permitted in the class name.
• The private and protected attribute name in class should be prepended with the character underscore (‘_’).
• Each method/ function name should begin with a verb.
• The first character of function/ method argument names should be lowercase.
• Use upper case letter as word separator
• Any name should begin with an alphabet.
• Digits may be used in the name but only after the alphabet.
• No special symbols can be used in names except for the underscore(‘_’).
• No keywords can be used as names.
• Pointer variables should be prepended with ‘p’ and place the asterisk ‘*’ close to the name instead of the pointer type.
• Static variables should be prepended with ‘s’.
• Getter should use same name as attribute name.
• Setter should use same name as attribute name with set prefix and upper case the first letter of name.

e.g:

class Esp3dAuthenticationService {
public:
    bool begin();
    bool isAdmin (const char *pwd);
    char * getPassword ();
private:
    std::string _adminPwd;
    char *_pName;
    static char _sLogin; 
}

Function/Procedure

• Each Function/Procedure name should begin with a verb.
• The first character of argument names should be lowercase.
• Use upper case letter as word separator
• Any name should begin with an alphabet.
• Digits may be used in the name but only after the alphabet.
• No special symbols can be used in names except for the underscore(‘_’).
• No keywords can be used as names.

Namespace

• Namespace names are all lower-case, with words separated by underscores.
• Do not use using but full namespace instead for clarity
  e.g:

namespace esp3d_hal{
    int64_t millis();
}

usage example: esp3d_hal::millis();

typedef

• If variable
  • Use lower case for names
  • Use underscores as words separators
  • Add suffix _t e.g: typedef int setting_index_t
• If function
  • Follow function naming syntax
  • Add suffix _t e.g: typedef std::function<bool(const char*, const char*,const char*)> processingFunction_t;

0 and nullptr/NULL

Use nullptr for pointers, and ‘\0’ for chars (and not the 0 literal).

For pointers (address values), use nullptr, as this provides type-safety.

Use ‘\0’ for the null character. Using the correct type makes the code more readable.

sizeof

Prefer sizeof(varname) to sizeof(type). sizeof(varname) will update appropriately if someone changes the variable type either now or later.

auto type

Only use auto type if no need to to do type deduction, C++ code is usually clearer when types are explicit, especially when type deduction would depend on information from distant parts of the code.

Casting

• Use C++-style casts
  e.g: static_cast<float>(double_value)
• Do not use C cast unless the cast is to void
  e.g: (int)3.5;

Initialization

• Do not mix brace initialization and = for readibility

Lambda Expressions

//TODO

Inspired from :

• Naming Convention in C++
• Google C++ Style Guide