1 files changed, 605 insertions, 0 deletions

diff --git a/termbox2/termbox2.ha b/termbox2/termbox2.ha
new file mode 100644
index 0000000..f8476ee
--- /dev/null
+++ b/termbox2/termbox2.ha
@@ -0,0 +1,605 @@
+use encoding::utf8;
+use fmt;
+use types::c;
+
+// Type for key values, see [[termbox2::KEY]].
+export type key = u16;
+
+// ASCII constants, see [[termbox2::key_event]].key.
+export def KEY = struct {
+        CTRL_TILDE: key = 0x00,
+        CTRL_2: key = 0x00, // clash with CTRL_TILDE
+        CTRL_A: key = 0x01,
+        CTRL_B: key = 0x02,
+        CTRL_C: key = 0x03,
+        CTRL_D: key = 0x04,
+        CTRL_E: key = 0x05,
+        CTRL_F: key = 0x06,
+        CTRL_G: key = 0x07,
+        BACKSPACE: key = 0x08,
+        CTRL_H: key = 0x08, // clash with CTRL_BACKSPACE
+        TAB: key = 0x09,
+        CTRL_I: key = 0x09, // clash with TAB
+        CTRL_J: key = 0x0a,
+        CTRL_K: key = 0x0b,
+        CTRL_L: key = 0x0c,
+        ENTER: key = 0x0d,
+        CTRL_M: key = 0x0d, // clash with ENTER
+        CTRL_N: key = 0x0e,
+        CTRL_O: key = 0x0f,
+        CTRL_P: key = 0x10,
+        CTRL_Q: key = 0x11,
+        CTRL_R: key = 0x12,
+        CTRL_S: key = 0x13,
+        CTRL_T: key = 0x14,
+        CTRL_U: key = 0x15,
+        CTRL_V: key = 0x16,
+        CTRL_W: key = 0x17,
+        CTRL_X: key = 0x18,
+        CTRL_Y: key = 0x19,
+        CTRL_Z: key = 0x1a,
+        ESC: key = 0x1b,
+        CTRL_LSQ_BRACKET: key = 0x1b, // clash with 'ESC'
+        CTRL_3: key = 0x1b, // clash with 'ESC'
+        CTRL_4: key = 0x1c,
+        CTRL_BACKSLASH: key = 0x1c, // clash with 'CTRL_4'
+        CTRL_5: key = 0x1d,
+        CTRL_RSQ_BRACKET: key = 0x1d, // clash with 'CTRL_5'
+        CTRL_6: key = 0x1e,
+        CTRL_7: key = 0x1f,
+        CTRL_SLASH: key = 0x1f, // clash with 'CTRL_7'
+        CTRL_UNDERSCORE: key = 0x1f, // clash with 'CTRL_7'
+        SPACE: key = 0x20,
+        BACKSPACE2: key = 0x7f,
+        CTRL_8: key = 0x7f, // clash with 'BACKSPACE2'
+        F1: key = (0xffff - 0),
+        F2: key = (0xffff - 1),
+        F3: key = (0xffff - 2),
+        F4: key = (0xffff - 3),
+        F5: key = (0xffff - 4),
+        F6: key = (0xffff - 5),
+        F7: key = (0xffff - 6),
+        F8: key = (0xffff - 7),
+        F9: key = (0xffff - 8),
+        F10: key = (0xffff - 9),
+        F11: key = (0xffff - 10),
+        F12: key = (0xffff - 11),
+        INSERT: key = (0xffff - 12),
+        DELETE: key = (0xffff - 13),
+        HOME: key = (0xffff - 14),
+        END: key = (0xffff - 15),
+        PGUP: key = (0xffff - 16),
+        PGDN: key = (0xffff - 17),
+        ARROW_UP: key = (0xffff - 18),
+        ARROW_DOWN: key = (0xffff - 19),
+        ARROW_LEFT: key = (0xffff - 20),
+        ARROW_RIGHT: key = (0xffff - 21),
+        BACK_TAB: key = (0xffff - 22),
+        MOUSE_LEFT: key = (0xffff - 23),
+        MOUSE_RIGHT: key = (0xffff - 24),
+        MOUSE_MIDDLE: key = (0xffff - 25),
+        MOUSE_RELEASE: key = (0xffff - 26),
+        MOUSE_WHEEL_UP: key = (0xffff - 27),
+        MOUSE_WHEEL_DOWN: key = (0xffff - 28),
+};
+
+// Type for key modifiers, see [[termbox2::MOD]].
+export type mod = u8;
+
+// Key modifiers (bitwise), see [[termbox2::event]].mod.
+export def MOD = struct {
+        ALT: mod = 1,
+        CTRL: mod = 2,
+        SHIFT: mod = 4,
+        MOTION: mod = 8,
+};
+
+// Type for input modes, see [[termbox2::INPUT]].
+export type input_mode = int;
+
+// Input modes (bitwise), see [[termbox2::set_input_mode]].
+export def INPUT = struct {
+        CURRENT: input_mode = 0,
+        ESC: input_mode = 1,
+        ALT: input_mode = 2,
+        MOUSE: input_mode = 4,
+};
+
+// Type for output modes, see [[termbox2::OUTPUT]].
+export type output_mode = int;
+
+// Output modes, see [[termbox2::set_output_mode]].
+export def OUTPUT = struct {
+        CURRENT: output_mode = 0,
+        NORMAL: output_mode = 1,
+        _256: output_mode = 2,
+        _216: output_mode = 3,
+        GRAYSCALE: output_mode = 4,
+        TRUECOLOR: output_mode = 5, // only available if OPT_ATTR_W >= 32
+};
+
+// Type for error return values, see [[termbox2::ERR]].
+export type err = !int;
+
+// Common error return values.
+//
+// Library behavior is undefined after receiving ERR.MEM.
+// Callers may attempt reinitializing by freeing memory, invoking
+// [[termbox2::shutdown]], then [[termbox2::init]].
+export def ERR = struct {
+        ERR: err = -1,
+        NEED_MORE: err = -2,
+        INIT_ALREADY: err = -3,
+        INIT_OPEN: err = -4,
+        MEM: err = -5,
+        NO_EVENT: err = -6,
+        NO_TERM: err = -7,
+        NOT_INIT: err = -8,
+        OUT_OF_BOUNDS: err = -9,
+        READ: err = -10,
+        RESIZE_IOCTL: err = -11,
+        RESIZE_PIPE: err = -12,
+        RESIZE_SIGACTION: err = -13,
+        POLL: err = -14,
+        SELECT: err = -14,
+        TCGETATTR: err = -15,
+        TCSETATTR: err = -16,
+        UNSUPPORTED_TERM: err = -17,
+        RESIZE_WRITE: err = -18,
+        RESIZE_POLL: err = -19,
+        RESIZE_SELECT: err = -19,
+        RESIZE_READ: err = -20,
+        RESIZE_SSCANF: err = -21,
+        CAP_COLLISION: err = -22,
+        HARE_BUILD: err = -9990, // Additional error type
+        HARE_INVALID_UTF8: err = -9991, // Additional error type
+        HARE_OTHER: err = -9992, // Additional error type
+};
+
+// An incoming key press event. Note that there is overlap between
+// MOD.CTRL and KEY.CTRL_* keys. MOD.CTRL and MOD.SHIFT are only set
+// as modifiers to KEY.ARROW_*.
+export type key_event = struct {
+        mod: mod, // Modifier
+        key_or_ch: (key | rune), // A [[termbox2::KEY]] or a Unicode code point
+};
+
+// An incoming resize event.
+export type resize_event = struct {
+        w: i32, // resize width
+        h: i32, // resize height
+};
+
+// An incoming mouse event.
+export type mouse_event = struct {
+        key: key, // Mouse button, e.g. termbox2::KEY.MOUSE_LEFT
+        x: i32,
+        y: i32,
+};
+
+// The C data structure for an event, for compatibility.
+type tb_event = struct {
+        t: u8,
+        mod: u8,
+        key: u16,
+        ch: u32,
+        w: i32,
+        h: i32,
+        x: i32,
+        y: i32,
+};
+
+def TB_EVENT_KEY: u8 = 1;
+def TB_EVENT_RESIZE: u8 = 2;
+def TB_EVENT_MOUSE: u8 = 3;
+fn tb_event_to_event(e: tb_event) (event | err) = switch (e.t) {
+        case TB_EVENT_KEY => yield key_event {
+                mod = e.mod,
+                key_or_ch = if (e.key != 0) e.key: key else e.ch: rune,
+        };
+        case TB_EVENT_RESIZE => yield resize_event {
+                w = e.w,
+                h = e.h,
+        };
+        case TB_EVENT_MOUSE => yield mouse_event {
+                key = e.key,
+                x = e.x,
+                y = e.y,
+        };
+        case => yield ERR.HARE_OTHER;
+        };
+
+// Any incoming event from the tty.
+export type event = (key_event | resize_event | mouse_event);
+
+fn build_opts_match() bool =
+        (has_egc() == OPT_EGC) &&
+        (attr_width() == OPT_ATTR_W) &&
+        (has_truecolor() == (OPT_ATTR_W == 32 || OPT_ATTR_W == 64));
+
+fn void_or_err(r: int) (void | err) = if (r < 0) r: err;
+fn int_or_err(r: int) (int | err) = if (r < 0) r: err else r;
+fn size_or_err(r: int) (size | err) = if (r < 0) r: err else r: size;
+fn str_or_err(cstr: *c::char) (str | err) = match(c::tostr(cstr)) {
+        case utf8::invalid => yield ERR.HARE_INVALID_UTF8;
+        case let s: str => yield s;
+};
+
+// Initialize the termbox library. This function should be called before
+// any other functions. After successful initialization, the library must
+// be finalized using [[termbox2::shutdown]].
+export fn init() (void | err) =
+        if (!build_opts_match())
+                ERR.HARE_BUILD
+        else
+                void_or_err(tb_init());
+@symbol("tb_init") fn tb_init() int;
+
+// Same as [[termbox2::init]], but allows to specify a file path in place
+// of the default /dev/tty.
+export fn init_file(path: str) (void | err) = {
+        let c_path = c::fromstr(path)!;
+        defer free(c_path);
+        return if (!build_opts_match())
+                ERR.HARE_BUILD
+        else
+                void_or_err(tb_init_file(c_path));
+};
+@symbol("tb_init_file") fn tb_init_file(cstr: *c::char) int;
+
+// Same as [[termbox2::init]], but allows to specify an output
+// file descriptor.
+export fn init_fd(ttyfd: int) (void | err) =
+        if (!build_opts_match())
+                ERR.HARE_BUILD
+        else
+                void_or_err(tb_init_fd(ttyfd));
+@symbol("tb_init_fd") fn tb_init_fd(fd: int) int;
+
+// Same as [[termbox2::init]], but allows to specify input and output
+// file descriptors.
+export fn init_rwfd(rfd: int, wfd: int) (void | err) =
+        if (!build_opts_match())
+                ERR.HARE_BUILD
+        else
+                void_or_err(tb_init_rwfd(rfd, wfd));
+@symbol("tb_init_rwfd") fn tb_init_rwfd(rfd: int, wfd: int) int;
+
+// Finalizes the library.
+export fn shutdown() (void | err) = void_or_err(tb_shutdown());
+@symbol("tb_shutdown") fn tb_shutdown() int;
+
+// Return the width of the internal back buffer (which is the same as the
+// terminal's window width in columns). The internal buffer can be resized
+// after [[termbox2::clear]] or [[termbox2::present]] calls. Returns ERR.ERR
+// when called before [[termbox2::init]] or after [[termbox2::shutdown]].
+export fn width() (size | err) = size_or_err(tb_width());
+@symbol("tb_width") fn tb_width() int;
+
+// Return the height of the internal back buffer (which is the same as the
+// terminal's window width in rows). The internal buffer can be resized
+// after [[termbox2::clear]] or [[termbox2::present]] calls. Returns ERR.ERR
+// when called before [[termbox2::init]] or after [[termbox2::shutdown]].
+export fn height() (size | err) = size_or_err(tb_height());
+@symbol("tb_height") fn tb_height() int;
+
+// Clear the internal back buffer using [[termbox2::ATTRIBUTE]].DEFAULT.
+export fn clear() (void | err) = void_or_err(tb_clear());
+@symbol("tb_clear") fn tb_clear() int;
+
+// Clear the internal back buffer using the specified attributes.
+export fn set_clear_attrs(fg: uattr, bg: uattr) (void | err) =
+        void_or_err(tb_set_clear_attrs(fg, bg));
+@symbol("tb_set_clear_attrs") fn tb_set_clear_attrs(fg: uattr, bg: uattr) int;
+
+// Synchronize the internal back buffer with the terminal by
+// writing to tty.
+export fn present() (void | err) = void_or_err(tb_present());
+@symbol("tb_present") fn tb_present() int;
+
+// Clear the internal front buffer effectively forcing a complete re-render
+// of the back buffer to the tty. It is not necessary to call this under
+// normal circumstances.
+export fn invalidate() (void | err) = void_or_err(tb_invalidate());
+@symbol("tb_invalidate") fn tb_invalidate() int;
+
+// Set the position of the cursor. Upper-left cell is (0, 0).
+export fn set_cursor(cx: int, cy: int) (void | err) =
+        void_or_err(tb_set_cursor(cx, cy));
+@symbol("tb_set_cursor") fn tb_set_cursor(x: int, y: int) int;
+
+// Hide the cursor.
+export fn hide_cursor() (void | err) = void_or_err(tb_hide_cursor());
+@symbol("tb_hide_cursor") fn tb_hide_cursor() int;
+
+// Set cell contents in the internal back buffer at the specified position.
+// Non-printable runes are replaced with U+FFFD at render time.
+export fn set_cell(
+        x: int,
+        y: int,
+        ch: rune,
+        fg: uattr,
+        bg: uattr,
+) (void | err) = void_or_err(tb_set_cell(x, y, ch: u32, fg, bg));
+@symbol("tb_set_cell") fn tb_set_cell(
+        x: int,
+        y: int,
+        ch: u32,
+        fg: uattr,
+        bg: uattr,
+) int;
+
+// Set extended cell contents. Only available when OPT_ATTR_W >= 32.
+// See also [[termbox2::set_cell]] and [[termbox2::cell]].
+export fn set_cell_ex(
+        x: int,
+        y: int,
+        ch: []rune,
+        fg: uattr,
+        bg: uattr,
+) (void | err) =
+        void_or_err(tb_set_cell_ex(x, y, &ch[0]: *u32, len(ch), fg, bg));
+@symbol("tb_set_cell_ex") fn tb_set_cell_ex(
+        x: int,
+        y: int,
+        ch: *u32,
+        n: size,
+        fg: uattr,
+        bg: uattr,
+) int;
+
+// Add one character to the cell's ech. Only available when OPT_ATTR_W >= 32.
+// See also [[termbox2::set_cell_ex]] and [[termbox2::cell]].
+export fn extend_cell(x: int, y: int, ch: rune) (void | err) =
+        void_or_err(tb_extend_cell(x, y, ch: u32));
+@symbol("tb_extend_cell") fn tb_extend_cell(x: int, y: int, ch: u32) int;
+
+// Set the input mode, see [[termbox2::INPUT]].
+//
+// Termbox has two input modes:
+// - INPUT.ESC When escape (\x1b) is in the buffer and there's no match
+// for an escape sequence, a key event for [[termbox2::KEY]].ESC is returned.
+// - INPUT.ALT When escape (\x1b) is in the buffer and there's no match
+// for an an escape sequence, the next keyboard event is returned with a
+// [[termbox2::MOD]].ALT modifier.
+//
+// You can also apply termbox2::INPUT.MOUSE via bitwise OR operation to either
+// of the modes (e.g., INPUT.ALT | INPUT.MOUSE) to receive
+// [[termbox2::mouse_event]] events. If none of the main two modes were
+// set, but the mouse mode was, INPUT.ESC is used. If for some reason you've
+// decided to use INPUT.ESC | INPUT.ALT, it will behave as if only INPUT.ESC
+// was selected.
+//
+// If mode is INPUT.CURRENT, return the current input mode.
+//
+// The default input mode is INPUT.ESC.
+export fn set_input_mode(mode: input_mode) (int | err) =
+        int_or_err(tb_set_input_mode(mode: int));
+@symbol("tb_set_input_mode") fn tb_set_input_mode(mode: int) int;
+
+// Set the output mode, see [[termbox2::OUTPUT]].
+//
+// Termbox has multiple output modes:
+//
+// 1. OUTPUT.NORMAL => [0..8]
+// 
+// This mode provides 8 different colors (see [[termbox2::COLOR]]), plus
+// COLOR.DEFAULT which skips sending a color code (i.e., uses the terminal's
+// default color). Colors may be bitwise OR'd with style attributes, see
+// [[termbox2::ATTRIBUTE]]. Extra attributes are available if OPT_ATTR_W == 64.
+//
+// Some notes: ATTRIBUTE.REVERSE and ATTRIBUTE.BRIGHT can be applied as either
+// fg or bg attributes for the same effect. The rest of the attributes apply to
+// fg only and are ignored as bg attributes.
+//
+// Example usage:
+// 
+//      let fg = termbox2::COLOR.BLACK | termbox2::ATTRIBUTE.BOLD;
+//      let bg = termbox2::COLOR.RED;
+//      termbox2::set_cell(x, y, '@', fg, bg);
+//
+// 2. OUTPUT._256 => [0..255] + ATTRIBUTE.HI_BLACK
+//
+// In this mode you get 256 distinct colors (plus default):
+// - 0x00 (1): ATTRIBUTE.DEFAULT
+// - ATTRIBUTE.HI_BLACK (1): COLOR.BLACK in OUTPUT.NORMAL
+// - 0x01..0x07 (7): the next 7 colors as in OUTPUT.NORMAL
+// - 0x08..0x0f (8): bright versions of the above
+// - 0x10..0xe7 (216): 216 different colors
+// - 0xe8..0xff (24): 24 different shades of gray
+//
+// All style attributes except ATTRIBUTE.BRIGHT may be bitwise OR'd as in
+// OUTPUT.NORMAL.
+//
+// Note COLOR.BLACK must be used for black, as 0x00 represents default.
+//
+// 3. OUTPUT._216 => [0..216]
+//
+// This mode supports the 216-color range of OUTPUT._256 only, but you
+// don't need to provide an offset:
+// - 0x00 (1): COLOR.DEFAULT
+// - 0x01..0xd8 (216): 216 different colors
+//
+// 4. OUTPUT.GRAYSCALE => [0..24]
+//
+// This mode supports the 24-color range of OUTPUT._256 only, but you
+// don't need to provide an offset:
+// - 0x00 (1): COLOR.DEFAULT
+// - 0x01..0x18 (24): 24 different shades of gray
+//
+// 5. OUTPUT.TRUECOLOR => [0x000000..0xffffff] + ATTRIBUTE.HI_BLACK
+//
+// This mode provides 24-bit color on supported terminals.
+// The format is 0xRRGGBB.
+//
+// All style attributes except ATTRIBUTE.BRIGHT may be bitwise OR'd as in
+// OUTPUT.NORMAL.
+//
+// Note ATTRIBUTE.HI_BLACK must be used for black, as 0x000000 represents
+// default.
+//
+// To use the terminal default color (i.e., to not send an escape code), pass
+// COLOR.DEFAULT. For convenience, the value 0 is interpreted as COLOR.DEFAULT
+// in all modes.
+//
+// Note, cell attributes persist after switching output modes. Any translation
+// between, for example, OUTPUT.NORMAL's COLOR.RED and OUTPUT.TRUECOLOR's
+// 0xff0000 must be performed by the caller. Also note that cells previously
+// rendered in one mode may persist unchanged until the front buffer is cleared
+// (such as after a resize event) at which point it will be re-interpreted and
+// flushed according to the current mode. Callers may invoke
+// [[termbox2::invalidate]] if it is desirable to immediately re-interpret
+// and flush the entire screen according to the current mode.
+//
+// Note, not all terminals support all output modes, especially beyond
+// OUTPUT.NORMAL. There is also no very reliable way to determine color
+// support dynamically. If portability is desired, callers are recommended to
+// use OUTPUT.NORMAL or make output mode end-user configurable. The same
+// advice applies to style attributes.
+//
+// If mode is OUTPUT.CURRENT, return the current output mode.
+//
+// The default output mode is OUTPUT.NORMAL.
+export fn set_output_mode(mode: output_mode) (int | err) =
+        int_or_err(tb_set_output_mode(mode: int));
+@symbol("tb_set_output_mode") fn tb_set_output_mode(mode: int) int;
+
+// Wait for an event up to timeout_ms milliseconds and return it. If no event
+// is available within the timeout period, ERR.NO_EVENT is returned. On a resize
+// event, the underlying select(2) call may be interrupted, yielding a return
+// code of ERR.POLL.
+export fn peek_event(timeout_ms: size) (event | err) = {
+        let e = tb_event {
+                t = 0,
+                mod = 0,
+                key = 0,
+                ch = 0,
+                w = 0,
+                h = 0,
+                x = 0,
+                y = 0,
+        };
+        let r = tb_peek_event(&e, timeout_ms: int);
+        return if (r < 0) r: err else tb_event_to_event(e);
+};
+@symbol("tb_peek_event") fn tb_peek_event(ev: *tb_event, t: int) int;
+
+// Same as [[termbox2::peek_event]] except no timeout.
+export fn poll_event() (event | err) = {
+        let e = tb_event {
+                t = 0,
+                mod = 0,
+                key = 0,
+                ch = 0,
+                w = 0,
+                h = 0,
+                x = 0,
+                y = 0,
+        };
+        let r = tb_poll_event(&e);
+        return if (r < 0) r: err else tb_event_to_event(e);
+};
+@symbol("tb_poll_event") fn tb_poll_event(ev: *tb_event) int;
+
+// Internal termbox fds that can be used with poll(2), select(2), etc.
+// externally. Callers must invoke [[termbox2::poll_event]] or
+// [[termbox2::peek_event]] if fds become readable.
+export fn get_fds() ((int, int) | err) = {
+        let ttyfd: int = 0;
+        let resizefd: int = 0;
+        let r = tb_get_fds(&ttyfd, &resizefd);
+        return if (r < 0) r: err else (ttyfd, resizefd);
+};
+@symbol("tb_get_fds") fn tb_get_fds(ttyfd: *int, resizefd: *int) int;
+
+// Print function. On success, it returns the width of the printed string.
+// Strings are interpreted as UTF-8.
+//
+// No attempt is made to do proper grapheme cluster parsing. With
+// [[termbox2::OPT_EGC]] enabled, as a very coarse approximation, codepoints
+// of width 0 are tacked on to the previous codepoint via
+// [[termbox2::extend_cell]].
+//
+// Non-printable characters (iswprint(3)) and truncated UTF-8 byte sequences
+// are replaced with U+FFFD.
+//
+// Newlines (\n) are supported with the caveat that the return value will be
+// the width of the string as if it were on a single line.
+//
+// If the starting coordinate is out of bounds, ERR.OUT_OF_BOUNDS is returned.
+// If the starting coordinates is in bounds, but goes out of bounds, then the
+// out-of-bounds portions of the string are ignored.
+//
+// For finer control, use [[termbox2::set_cell]].
+export fn print(
+        x: int,
+        y: int,
+        fg: uattr,
+        bg: uattr,
+        fmt_str: str,
+        args: fmt::field...
+) (size | err) = {
+        let s = fmt::asprintf(fmt_str, args...)!;
+        defer free(s);
+        let cstr = c::fromstr(s)!;
+        defer free(cstr);
+        let outw: size = 0;
+        let e = tb_print_ex(x, y, fg, bg, &outw, cstr);
+        return if (e < 0) e: err else outw;
+};
+@symbol("tb_print_ex") fn tb_print_ex(
+        x: int,
+        y: int,
+        fg: uattr,
+        bg: uattr,
+        out_w: *size,
+        cstr: const *c::char,
+) int;
+
+// Send raw bytes to the terminal.
+export fn send(buf: []u8) (void | err) =
+        void_or_err(tb_send(&buf[0]: *c::char, len(buf)));
+@symbol("tb_send") fn tb_send(buf: const *c::char, nbuf: size) int;
+
+// Returns a string explaining the given error code. The caller must free
+// the return value.
+export fn strerror(e: err) str = switch (e) {
+        case ERR.HARE_BUILD => 
+                yield fmt::asprintf(
+                        "Cannot initialize Termbox because of a mismatch "
+                        "between the C and Hare build options.\n"
+                        "Hare OPT_EGC is {} and C TB_OPT_EGC is {}\n"
+                        "Hare OPT_ATTR_W {} and  C TB_OPT_ATTR_W is {}",
+                        OPT_EGC, has_egc(), OPT_ATTR_W, attr_width()
+                )!;
+        case ERR.HARE_INVALID_UTF8 => 
+                yield fmt::asprintf("Invalid UTF8 sequence recieved from tb")!;
+        case ERR.HARE_OTHER =>
+                yield fmt::asprintf("Unknown error in the Hare bindings")!;
+        case => yield match (str_or_err(tb_strerror(e: int))) {
+                case err => yield fmt::asprintf(
+                        "Unexpected error while interpreting previous error"
+                )!;
+                case let estr: str => yield estr;
+        };
+};
+@symbol("tb_strerror") fn tb_strerror(e: int) const *c::char;
+
+// Returns true if the the C termbox2 library was compiled with truecolor
+// support (i.e., if [[termbox2::OPT_ATTR_W]] is 32 or 64).
+export fn has_truecolor() bool = tb_has_truecolor() != 0;
+@symbol("tb_has_truecolor") fn tb_has_truecolor() int;
+
+// Returns true if the the C termbox2 library was compiled with EGC
+// support (i.e., if [[termbox2::OPT_EGC]] is true).
+export fn has_egc() bool = tb_has_egc() != 0;
+@symbol("tb_has_egc") fn tb_has_egc() int;
+
+// Returns the value of the TB_OPT_ATTR_W compile time option of the
+// C termbox2 library.
+export fn attr_width() size = tb_attr_width(): size;
+@symbol("tb_attr_width") fn tb_attr_width() int;
+
+// Returns the string version of the C termbox2 library.
+export fn version() (str | err) = str_or_err(tb_version());
+@symbol("tb_version") fn tb_version() const *c::char;