EmberLite C Coding Style Guide

General principles

• Simple beats clever
• Consistency beats personal preference
• Clear interfaces beat implementation tricks
• Design for embedded / SDK / cross-platform use

Naming conventions

Use snake_case consistently in C. This is the core decision.

Functions

int ember_connect(void);
int ember_send_packet(const uint8_t *data, size_t length);
void ember_disconnect(void);

Rules:

• All lowercase
• Separate words with _
• Must use a module prefix (very important)

Recommended prefixes:

ember_*
eb_*

Variables

int packet_count;
uint8_t buffer_size;

• snake_case
• Short and clear

Global variables

int g_packet_count;

• Use the g_ prefix
• Prefer to avoid globals

Macros

#define EMBER_MAX_PACKET_SIZE 1024
#define EMBER_TIMEOUT_MS      1000

• ALL_CAPS with _
• Must include a module prefix

typedef / struct / enum

For type names, pick PascalCase or snake_case and stick to one project-wide style.

We recommend PascalCase (closer to C++):

typedef struct {
    uint8_t *data;
    size_t length;
} EmberPacket;

Enumerations:

typedef enum {
    EMBER_STATE_DISCONNECTED,
    EMBER_STATE_CONNECTING,
    EMBER_STATE_CONNECTED
} EmberState;

• Enumerators must be ALL_CAPS
• Include a module prefix

Module design

C has no namespaces; naming discipline is what keeps large C codebases sane.

One prefix per module

Module	Prefix
core	ember_
transport	ember_transport_
protocol	ember_proto_

Example:

int ember_transport_init(void);
int ember_transport_send(const uint8_t *data, size_t len);

File naming

snake_case

ember.c
ember_transport.c
ember_protocol.c
packet_parser.c

Struct design

Do not expose internal details (approximate “encapsulation”)

typedef struct EmberClient EmberClient;
struct EmberClient {
    int socket_fd;
    int state;
};

Or, going further (recommended for SDKs):

typedef struct EmberClient EmberClient;

EmberClient* ember_create(void);
void ember_destroy(EmberClient* client);

This enables a lightweight “pseudo-OOP” style.

Function design

Consistent return values

int ember_connect(void);  // 0 = success, <0 = error

Recommended:

• 0 for success
• Negative values for error codes

Output parameters

int ember_receive(uint8_t *buffer, size_t *length);

✔ Use pointers to return data
✔ Avoid returning large structs by value (better for embedded)

Booleans

bool is_connected;
bool has_error;

Functions:

bool ember_is_connected(void);

✔ Prefer is_, has_, can_ prefixes

Naming anti-patterns

Avoid:

int Connect();     // ❌ C++-style name
int getCount();    // ❌ camelCase

Avoid missing prefixes:

int send_packet(); // ❌ pollutes the global namespace

Avoid cryptic abbreviations:

int pkt_cnt;       // ❌

Header guards

#ifndef EMBER_TRANSPORT_H
#define EMBER_TRANSPORT_H

// ...

#endif

✔ Guard macro name matches the file name in UPPER_SNAKE_CASE

Full example

// ember_client.h

#ifndef EMBER_CLIENT_H
#define EMBER_CLIENT_H

#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>

typedef struct EmberClient EmberClient;

EmberClient* ember_create(void);
void ember_destroy(EmberClient* client);

int ember_connect(EmberClient* client);
int ember_disconnect(EmberClient* client);

int ember_send_packet(EmberClient* client,
                      const uint8_t* data,
                      size_t length);

bool ember_is_connected(const EmberClient* client);

#endif