sp.h Overview

• sp.h is a single-header C standard library replacement
• You MUST annotate references to functions from sp.h with verbatim function headers
• When providing references to code from sp.h, you MUST provide a matching declaration from references/index.md. Function names without the full declaration are COMPLETELY useless, and WILL NOT be tolerated. user: How do I use the asset registry from sp.h? assistant: [Reads the index, uses the Task tool to search through sources bundled with skill (sp.h, spn.c), includes "sp_str_t sp_str_sub(sp_str_t str, s32 index, s32 len)" in answer] user: Write a function that reads a file and logs its contends assistant: [Searches through bundled source code with Task tool to find relevant APIs and writes function]
• NEVER, EVER MODIFY THE REFERENCE CODE

Usage

• Search references/index.md before trying to search through the codebase. Do not guess; refer to references/index.md to find a precise search term. user: How do I read a file in sp.h? assistant: [Reads index.md, searches through sp.h and spn.c with Task tool, provides concise, annotated answer]
• Search through references/sp.h judiciously as needed; do not guess symbol names, function signatures, or implementation details. Read the source code.
• Function signatures are prefixed with SP_API
• Types are prefixed with sp_ and suffixed with _t

Rules

• Never use malloc, calloc, or realloc; use sp_alloc (which zero initializes)
• Unless explicitly interfacing with an existing C API, never use const char*; use sp_str_t (pointer + length)
• Never use strcmp, strlen, or any string.h functions with sp_str_t; use sp_str_*
• Never use strcmp, strlen, or any string.h functions with const char*; use sp_cstr_*
• Always use SP_ZERO_INITIALIZE(). When you need a type, use SP_ZERO_STRUCT(T)
• Always use sp_da(T) and sp_ht(T) for dynamic arrays and hash maps (sp_dyn_array_* and sp_ht_*)
• Always use sp_dyn_array_for(arr, it) and sp_ht_for(ht, it) to iterate sp_da and sp_ht
• Never check str.len > 0; always use !sp_str_empty(str)
• Always use C99 designated initializers for struct literals when possible
• Always use short literal types (s32, u8, c8, const c8*)
• Never use printf family; always use SP_LOG()
• Always use sp_carr_for() when iterating a C array
• Always explicitly handle all enum cases in a switch statement. Fallthroughs are OK, default is not.

Namespaces

Use these when searching through references/index.md, references/sp.h, or references/spn.c

• Memory: sp_alloc, sp_context, sp_allocator, sp_os
• Strings: sp_str, sp_str_builder, sp_cstr
• Containers: sp_dyn_array / sp_da, sp_ht, sp_rb
• IO: sp_io
• Process: sp_ps
• Filesystem: sp_os
• Platform: sp_os
• Time: sp_tm
• Concurrency: sp_thread, sp_mutex, sp_semaphore, sp_atomic, sp_spin_lock
• Logging: sp_format, SP_LOG, SP_FMT_*

Common Patterns

Initialization

// Always zero-initialize structs
sp_str_builder_t builder = SP_ZERO_INITIALIZE();
sp_dynamic_array_t arr = SP_ZERO_INITIALIZE();

String Handling

// Create strings
sp_str_t literal = sp_str_lit("hello");     // Compile-time string literal
sp_str_t view = sp_str_view(some_char_ptr); // Runtime C string (calculates length)
sp_str_t copy = sp_str_from_cstr("hello");  // Allocates and copies
const char* cstr = sp_str_to_cstr(str);

Dynamic Arrays (stb-style)

sp_dyn_array(int) numbers = SP_NULLPTR;
sp_dyn_array_push(numbers, 42);
sp_dyn_array_push(numbers, 100);

sp_dyn_array_for(numbers, i) {
  SP_LOG("numbers[{}] = {}", SP_FMT_U32(i), SP_FMT_S32(numbers[i]));
}

u32 count = sp_dyn_array_size(numbers);
u32 capacity = sp_dyn_array_capacity(numbers);

// Cleanup happens automatically via allocator

Hash Tables (stb-style)

sp_ht(s32, s32) hta = SP_NULLPTR;
sp_ht(sp_str_t, s32) htb = SP_NULLPTR;
sp_ht_set_fns(hta, sp_ht_on_hash_str_key, sp_ht_on_compare_str_key);

sp_ht_insert(htb, SP_LIT("answer"), 42);

s32* value_ptr = sp_ht_getp(htb, SP_LIT("answer"));

sp_ht_key_exists(htb, SP_LIT("answer"));

sp_ht_for(htb, it) {
  sp_str_t* key = sp_ht_it_getkp(map, it);
  s32* val = sp_ht_it_getp(map, it);
}

// Cleanup happens automatically via allocator

Formatting and Logging

// Type-safe formatting with color support
SP_LOG(
  "Processing {:fg cyan} with {} {}",
  SP_FMT_STR(name),
  SP_FMT_U32(count),
  SP_FMT_CSTR("items")
);

sp_str_t msg = sp_format("Result: {}", SP_FMT_S32(42));

// Colors: :fg, :bg, :color
// Colors: black, red, green, yellow, blue, magenta, cyan, white
// Add 'bright' prefix for bright variants

Switch Statements

// Always use braces, always handle all cases
switch (state) {
  case STATE_IDLE: {
    break;
  }
  case STATE_RUNNING: {
    break;
  }
  default: {
    SP_UNREACHABLE_CASE();
  }
}

Error Handling

// Return an enum for recoverable errors (consumer app may have their own error type)
sp_err_t load_config(sp_str_t path, config_t* config) {
  if (!sp_os_does_path_exist(path)) {
    SP_LOG("Config not found: {}", SP_FMT_STR(path));
    return SP_ERR_WHATEVER;
  }

  return SP_ERR_OK;
}

// Prefer to SP_ASSERT when possible
void process_array(int* arr, u32 size) {
  SP_ASSERT(arr);
  SP_ASSERT(size > 0);
}

// SP_FATAL is SP_LOG + SP_ASSERT(false)
if (critical_failure) {
  SP_FATAL("Cannot continue: {:fg red}", SP_FMT_STR(reason));
}