MoonLang Compiler (C++ Source)

English | 中文 · Official site: moon-lang.com

MoonLang is a lightweight static programming language implemented in C++ with LLVM. It supports dual syntax styles (: end and { }), and runs on Windows, Linux, macOS, and embedded platforms (ARM/RISC-V/ESP32). Compiled binaries are 15KB–300KB, suitable for MCU to desktop applications.

This repository contains compiler source only (frontend + LLVM backend + runtime). It does not include the standard library .moon files, examples, or executables.

Supported features
Examples
Syntax overview
Deploying and using moonc
Building this repository
Build scripts
Directory layout
License and copyright

Supported features

The runtime provides a full set of built-in capabilities. Modules can be disabled at build time via MOON_NO_XXX or at compile time via moonc --no-xxx for smaller binaries.

Language & types

| Area | Description | |------|-------------| | Types | int, float, string, bool, null, list, dict, functions, classes, closures, BigInt (arbitrary precision) | | Literals | Hex 0x, binary 0b, octal 0o; list/dict literals; multi-line strings | | Operators | Arithmetic, comparison, logical, bitwise (& \| ^ ~ << >>), power ^, string concat | | Control flow | if/elif/else, while, for-in, for-to, switch, break, continue | | Functions | Named functions, lambdas, default args, closures, variadic-style via list | | OOP | Classes, inheritance, super, self, constructors init | | Modules | import "path" as name, from "path" import a, b | | Errors | Try/catch/finally, throw, exception value |

I/O & filesystem

| Function / area | Description | |-----------------|-------------| | Console | print, input | | Files | read_file, write_file, append_file (binary-safe) | | Paths | exists, is_file, is_dir, list_dir, create_dir, file_size, getcwd, cd | | Path utils | join_path, basename, dirname, extension, absolute_path, copy_file, move_file, remove_file, remove_dir |

Date & time

| Area | Description | |------|-------------| | Time | time, now (ms), unix_time, sleep | | Format/parse | date_format, date_parse with format string and optional timezone | | Components | year, month, day, hour, minute, second, millisecond, weekday, day_of_year, week_of_year, quarter | | Arithmetic | make_time, add_seconds/minutes/hours/days/months/years, diff_seconds, diff_days | | Ranges | start_of_day, end_of_day, start_of_month, end_of_month | | Helpers | days_in_month, is_leap_year, is_weekend, is_today, is_same_day, timezone, utc_offset, set_timezone |

Math & numbers

| Area | Description | |------|-------------| | Basic | abs, min, max, pow, sqrt, floor, ceil, round, sign, clamp, lerp | | Trig | sin, cos, tan, asin, acos, atan, atan2, degrees, radians | | Log/exp | log, log10, log2, exp, sinh, cosh, tanh, hypot | | Stats | mean, median (on list) | | Random | random_int, random_float |

Strings & bytes

| Area | Description | |------|-------------| | String ops | len, substring, split, join, replace, trim, upper, lower, capitalize, title, contains, starts_with, ends_with, index_of, find, repeat, chr, ord | | Predicates | is_alpha, is_digit, is_alnum, is_space, is_lower, is_upper | | Padding | pad_left, pad_right, ltrim, rtrim | | Binary | bytes_to_string (byte list → string), strings are binary-safe (length stored in header) | | WebSocket | ws_parse_frame, ws_create_frame (low-level frame parse/create) |

Lists & dicts

| Area | Description | |------|-------------| | List | Index, set, append, insert, pop, remove, len, slice, contains, index_of, reverse, sort, sum, first, last, take, drop, shuffle, choice, unique, flatten, zip, count | | Functional | list_map, list_filter, list_reduce (with callback) | | Dict | get, set, has_key, keys, values, items, delete, merge | | Range | range(n) or range(start, end) or range(start, end, step) |

Network

| Area | Description | |------|-------------| | TCP | tcp_connect, tcp_listen, tcp_accept, tcp_send, tcp_recv, tcp_close; non-blocking: tcp_set_nonblocking, tcp_has_data, tcp_select, tcp_accept_nonblocking, tcp_recv_nonblocking | | UDP | udp_socket, udp_bind, udp_send, udp_recv, udp_close | | TLS (OpenSSL) | tls_connect, tls_listen, tls_accept, tls_send, tls_recv, tls_recv_all, tls_close; verify/hostname, cert/key/CA load, tls_wrap_client / tls_wrap_server |

Controlled by MOON_HAS_NETWORK; TLS by MOON_HAS_TLS (optional OpenSSL). On Windows: IOCP/WSAPoll; on Linux: epoll.

GUI

| Area | Description | |------|-------------| | Basic | gui_init, gui_create, gui_show, gui_set_title, gui_set_size, gui_set_position, gui_close, gui_run, gui_quit, gui_alert, gui_confirm | | Advanced | gui_create_advanced (options: frameless, transparent, topmost, resizable, etc.), WebView: gui_load_url, gui_load_html, gui_on_message (JS ↔ MoonLang bridge) | | Tray | gui_tray_create, gui_tray_remove, gui_tray_set_menu, gui_tray_on_click, gui_show_window |

Windows: WebView2 (embedded Chromium).
Linux: WebKitGTK.
macOS: WKWebView.

Controlled by MOON_HAS_GUI. Disabled in --target=embedded and --target=mcu.

Regular expressions

| Area | Description | |------|-------------| | Match | regex_match, regex_search, regex_test, regex_groups, regex_named, regex_find_all, regex_find_all_groups | | Replace | regex_replace, regex_replace_all | | Split | regex_split, regex_split_n | | Compiled | regex_compile, then regex_match_compiled, regex_search_compiled, regex_find_all_compiled, regex_replace_compiled, regex_free | | Utils | regex_escape, regex_error |

Uses PCRE2. Disable with --no-regex or MOON_NO_REGEX.

JSON

| Function | Description | |----------|-------------| | json_encode | Value → JSON string | | json_decode | JSON string → value (list/dict/number/string/bool/null) |

Disable with --no-json or MOON_NO_JSON.

Async & concurrency

| Area | Description | |------|-------------| | Async | async(fn, ...args) — run on coroutine pool; yield; wait_all; num_goroutines, num_cpu | | Channels | Go-style: chan() or chan(n) (buffered), chan_send, chan_recv, chan_close, chan_is_closed | | Timers | set_timeout(callback, ms), set_interval(callback, ms), clear_timer(id) | | Sync | mutex(), lock, unlock, trylock, mutex_free; Atomics: atomic_counter(initial), atomic_add, atomic_get, atomic_set, atomic_cas |

Controlled by MOON_HAS_ASYNC. Disabled in --target=mcu.

DLL & FFI

| Area | Description | |------|-------------| | DLL | dll_load(path), dll_close, dll_func(handle, name); call: dll_call_int, dll_call_double, dll_call_str, dll_call_void; alloc_str / free_str for C strings; ptr_to_str, read_ptr, read_int32, write_ptr, write_int32 | | FFI | Declare C signatures in source; call C functions and pass/return values. |

Controlled by MOON_HAS_DLL / MOON_HAS_FFI. Disabled in --target=mcu.

System & misc

| Area | Description | |------|-------------| | Process | argv, env, set_env, exit, shell, shell_output, platform, getpid, system, exec | | Format | format(fmt, ...) (sprintf-style) | | Memory (MCU) | mem_stats, mem_reset, target_info | | GC | Reference counting + cycle collection; gc_collect, gc_enable, gc_set_threshold, gc_stats |

Hardware (HAL, embedded)

When built with HAL (e.g. ESP32, Raspberry Pi Pico, STM32):

| Area | Description | |------|-------------| | GPIO | gpio_init(pin, mode), gpio_write, gpio_read, gpio_deinit; modes: INPUT, OUTPUT, INPUT_PULLUP, INPUT_PULLDOWN | | PWM | pwm_init(pin, freq), pwm_write(pin, duty), pwm_deinit | | ADC | adc_init, adc_read, adc_deinit | | I2C | i2c_init(sda, scl, freq), i2c_write(addr, data), i2c_read(addr, length), i2c_deinit | | SPI | spi_init(mosi, miso, sck, freq), spi_transfer(data), spi_deinit | | UART | uart_init(tx, rx, baud), uart_write, uart_read, uart_available, uart_deinit | | Time | delay_ms, delay_us, millis, micros | | System | hal_init_runtime, hal_deinit_runtime, hal_platform_name, hal_debug_print |

Controlled by MOON_HAS_HAL (optional).

Build-time feature flags

| Flag / target | Effect | |---------------|--------| | Default | Full: GUI, network, TLS, regex, JSON, filesystem, float, DLL, async | | --target=embedded | No GUI; network and rest available | | `--target=m

Moonlang

Install / Use

README