quickjs-tart

repl.js (39185B)

---

 /*
  * QuickJS Read Eval Print Loop
  *
  * Copyright (c) 2017-2020 Fabrice Bellard
  * Copyright (c) 2017-2020 Charlie Gordon
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
 import * as std from "std";
 import * as os from "os";
 
 (function(g) {
     /* add 'os' and 'std' bindings */
     g.os = os;
     g.std = std;
 
     /* close global objects */
     var Object = g.Object;
     var String = g.String;
     var Array = g.Array;
     var Date = g.Date;
     var Math = g.Math;
     var isFinite = g.isFinite;
     var parseFloat = g.parseFloat;
 
     var colors = {
         none:    "\x1b[0m",
         black:   "\x1b[30m",
         red:     "\x1b[31m",
         green:   "\x1b[32m",
         yellow:  "\x1b[33m",
         blue:    "\x1b[34m",
         magenta: "\x1b[35m",
         cyan:    "\x1b[36m",
         white:   "\x1b[37m",
         gray:    "\x1b[30;1m",
         grey:    "\x1b[30;1m",
         bright_red:     "\x1b[31;1m",
         bright_green:   "\x1b[32;1m",
         bright_yellow:  "\x1b[33;1m",
         bright_blue:    "\x1b[34;1m",
         bright_magenta: "\x1b[35;1m",
         bright_cyan:    "\x1b[36;1m",
         bright_white:   "\x1b[37;1m",
     };
 
     var styles = {
         'default':    'bright_green',
         'comment':    'white',
         'string':     'bright_cyan',
         'regex':      'cyan',
         'number':     'green',
         'keyword':    'bright_white',
         'function':   'bright_yellow',
         'type':       'bright_magenta',
         'identifier': 'bright_green',
         'error':      'red',
         'result':     'bright_white',
         'error_msg':  'bright_red',
     };
 
     var history = [];
     var clip_board = "";
     var prec;
     var expBits;
     var log2_10;
 
     var pstate = "";
     var prompt = "";
     var plen = 0;
     var ps1 = "qjs > ";
     var ps2 = "  ... ";
     var utf8 = true;
     var show_time = false;
     var show_colors = true;
     var eval_start_time;
     var eval_time = 0;
 
     var mexpr = "";
     var level = 0;
     var cmd = "";
     var cursor_pos = 0;
     var last_cmd = "";
     var last_cursor_pos = 0;
     var history_index;
     var this_fun, last_fun;
     var quote_flag = false;
 
     var utf8_state = 0;
     var utf8_val = 0;
 
     var term_fd;
     var term_read_buf;
     var term_width;
     /* current X position of the cursor in the terminal */
     var term_cursor_x = 0;
 
     function termInit() {
         var tab;
         term_fd = std.in.fileno();
 
         /* get the terminal size */
         term_width = 80;
         if (os.isatty(term_fd)) {
             if (os.ttyGetWinSize) {
                 tab = os.ttyGetWinSize(term_fd);
                 if (tab)
                     term_width = tab[0];
             }
             if (os.ttySetRaw) {
                 /* set the TTY to raw mode */
                 os.ttySetRaw(term_fd);
             }
         }
 
         /* install a Ctrl-C signal handler */
         os.signal(os.SIGINT, sigint_handler);
 
         /* install a handler to read stdin */
         term_read_buf = new Uint8Array(64);
         os.setReadHandler(term_fd, term_read_handler);
     }
 
     function sigint_handler() {
         /* send Ctrl-C to readline */
         handle_byte(3);
     }
 
     function term_read_handler() {
         var l, i;
         l = os.read(term_fd, term_read_buf.buffer, 0, term_read_buf.length);
         for(i = 0; i < l; i++)
             handle_byte(term_read_buf[i]);
     }
 
     function handle_byte(c) {
         if (!utf8) {
             handle_char(c);
         } else if (utf8_state !== 0 && (c >= 0x80 && c < 0xc0)) {
             utf8_val = (utf8_val << 6) | (c & 0x3F);
             utf8_state--;
             if (utf8_state === 0) {
                 handle_char(utf8_val);
             }
         } else if (c >= 0xc0 && c < 0xf8) {
             utf8_state = 1 + (c >= 0xe0) + (c >= 0xf0);
             utf8_val = c & ((1 << (6 - utf8_state)) - 1);
         } else {
             utf8_state = 0;
             handle_char(c);
         }
     }
 
     function is_alpha(c) {
         return typeof c === "string" &&
             ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
     }
 
     function is_digit(c) {
         return typeof c === "string" && (c >= '0' && c <= '9');
     }
 
     function is_word(c) {
         return typeof c === "string" &&
             (is_alpha(c) || is_digit(c) || c == '_' || c == '$');
     }
 
     function ucs_length(str) {
         var len, c, i, str_len = str.length;
         len = 0;
         /* we never count the trailing surrogate to have the
          following property: ucs_length(str) =
          ucs_length(str.substring(0, a)) + ucs_length(str.substring(a,
          str.length)) for 0 <= a <= str.length */
         for(i = 0; i < str_len; i++) {
             c = str.charCodeAt(i);
             if (c < 0xdc00 || c >= 0xe000)
                 len++;
         }
         return len;
     }
 
     function is_trailing_surrogate(c)  {
         var d;
         if (typeof c !== "string")
             return false;
         d = c.codePointAt(0); /* can be NaN if empty string */
         return d >= 0xdc00 && d < 0xe000;
     }
 
     function is_balanced(a, b) {
         switch (a + b) {
         case "()":
         case "[]":
         case "{}":
             return true;
         }
         return false;
     }
 
     function print_color_text(str, start, style_names) {
         var i, j;
         for (j = start; j < str.length;) {
             var style = style_names[i = j];
             while (++j < str.length && style_names[j] == style)
                 continue;
             std.puts(colors[styles[style] || 'default']);
             std.puts(str.substring(i, j));
             std.puts(colors['none']);
         }
     }
 
     function print_csi(n, code) {
         std.puts("\x1b[" + ((n != 1) ? n : "") + code);
     }
 
     /* XXX: handle double-width characters */
     function move_cursor(delta) {
         var i, l;
         if (delta > 0) {
             while (delta != 0) {
                 if (term_cursor_x == (term_width - 1)) {
                     std.puts("\n"); /* translated to CRLF */
                     term_cursor_x = 0;
                     delta--;
                 } else {
                     l = Math.min(term_width - 1 - term_cursor_x, delta);
                     print_csi(l, "C"); /* right */
                     delta -= l;
                     term_cursor_x += l;
                 }
             }
         } else {
             delta = -delta;
             while (delta != 0) {
                 if (term_cursor_x == 0) {
                     print_csi(1, "A"); /* up */
                     print_csi(term_width - 1, "C"); /* right */
                     delta--;
                     term_cursor_x = term_width - 1;
                 } else {
                     l = Math.min(delta, term_cursor_x);
                     print_csi(l, "D"); /* left */
                     delta -= l;
                     term_cursor_x -= l;
                 }
             }
         }
     }
 
     function update() {
         var i, cmd_len;
         /* cursor_pos is the position in 16 bit characters inside the
            UTF-16 string 'cmd' */
         if (cmd != last_cmd) {
             if (!show_colors && last_cmd.substring(0, last_cursor_pos) == cmd.substring(0, last_cursor_pos)) {
                 /* optimize common case */
                 std.puts(cmd.substring(last_cursor_pos));
             } else {
                 /* goto the start of the line */
                 move_cursor(-ucs_length(last_cmd.substring(0, last_cursor_pos)));
                 if (show_colors) {
                     var str = mexpr ? mexpr + '\n' + cmd : cmd;
                     var start = str.length - cmd.length;
                     var colorstate = colorize_js(str);
                     print_color_text(str, start, colorstate[2]);
                 } else {
                     std.puts(cmd);
                 }
             }
             term_cursor_x = (term_cursor_x + ucs_length(cmd)) % term_width;
             if (term_cursor_x == 0) {
                 /* show the cursor on the next line */
                 std.puts(" \x08");
             }
             /* remove the trailing characters */
             std.puts("\x1b[J");
             last_cmd = cmd;
             last_cursor_pos = cmd.length;
         }
         if (cursor_pos > last_cursor_pos) {
             move_cursor(ucs_length(cmd.substring(last_cursor_pos, cursor_pos)));
         } else if (cursor_pos < last_cursor_pos) {
             move_cursor(-ucs_length(cmd.substring(cursor_pos, last_cursor_pos)));
         }
         last_cursor_pos = cursor_pos;
         std.out.flush();
     }
 
     /* editing commands */
     function insert(str) {
         if (str) {
             cmd = cmd.substring(0, cursor_pos) + str + cmd.substring(cursor_pos);
             cursor_pos += str.length;
         }
     }
 
     function quoted_insert() {
         quote_flag = true;
     }
 
     function abort() {
         cmd = "";
         cursor_pos = 0;
         return -2;
     }
 
     function alert() {
     }
 
     function beginning_of_line() {
         cursor_pos = 0;
     }
 
     function end_of_line() {
         cursor_pos = cmd.length;
     }
 
     function forward_char() {
         if (cursor_pos < cmd.length) {
             cursor_pos++;
             while (is_trailing_surrogate(cmd.charAt(cursor_pos)))
                 cursor_pos++;
         }
     }
 
     function backward_char() {
         if (cursor_pos > 0) {
             cursor_pos--;
             while (is_trailing_surrogate(cmd.charAt(cursor_pos)))
                 cursor_pos--;
         }
     }
 
     function skip_word_forward(pos) {
         while (pos < cmd.length && !is_word(cmd.charAt(pos)))
             pos++;
         while (pos < cmd.length && is_word(cmd.charAt(pos)))
             pos++;
         return pos;
     }
 
     function skip_word_backward(pos) {
         while (pos > 0 && !is_word(cmd.charAt(pos - 1)))
             pos--;
         while (pos > 0 && is_word(cmd.charAt(pos - 1)))
             pos--;
         return pos;
     }
 
     function forward_word() {
         cursor_pos = skip_word_forward(cursor_pos);
     }
 
     function backward_word() {
         cursor_pos = skip_word_backward(cursor_pos);
     }
 
     function accept_line() {
         std.puts("\n");
         history_add(cmd);
         return -1;
     }
 
     function history_add(str) {
         if (str) {
             history.push(str);
         }
         history_index = history.length;
     }
 
     function previous_history() {
         if (history_index > 0) {
             if (history_index == history.length) {
                 history.push(cmd);
             }
             history_index--;
             cmd = history[history_index];
             cursor_pos = cmd.length;
         }
     }
 
     function next_history() {
         if (history_index < history.length - 1) {
             history_index++;
             cmd = history[history_index];
             cursor_pos = cmd.length;
         }
     }
 
     function history_search(dir) {
         var pos = cursor_pos;
         for (var i = 1; i <= history.length; i++) {
             var index = (history.length + i * dir + history_index) % history.length;
             if (history[index].substring(0, pos) == cmd.substring(0, pos)) {
                 history_index = index;
                 cmd = history[index];
                 return;
             }
         }
     }
 
     function history_search_backward() {
         return history_search(-1);
     }
 
     function history_search_forward() {
         return history_search(1);
     }
 
     function delete_char_dir(dir) {
         var start, end;
 
         start = cursor_pos;
         if (dir < 0) {
             start--;
             while (is_trailing_surrogate(cmd.charAt(start)))
                 start--;
         }
         end = start + 1;
         while (is_trailing_surrogate(cmd.charAt(end)))
             end++;
 
         if (start >= 0 && start < cmd.length) {
             if (last_fun === kill_region) {
                 kill_region(start, end, dir);
             } else {
                 cmd = cmd.substring(0, start) + cmd.substring(end);
                 cursor_pos = start;
             }
         }
     }
 
     function delete_char() {
         delete_char_dir(1);
     }
 
     function control_d() {
         if (cmd.length == 0) {
             std.puts("\n");
             return -3; /* exit read eval print loop */
         } else {
             delete_char_dir(1);
         }
     }
 
     function backward_delete_char() {
         delete_char_dir(-1);
     }
 
     function transpose_chars() {
         var pos = cursor_pos;
         if (cmd.length > 1 && pos > 0) {
             if (pos == cmd.length)
                 pos--;
             cmd = cmd.substring(0, pos - 1) + cmd.substring(pos, pos + 1) +
                 cmd.substring(pos - 1, pos) + cmd.substring(pos + 1);
             cursor_pos = pos + 1;
         }
     }
 
     function transpose_words() {
         var p1 = skip_word_backward(cursor_pos);
         var p2 = skip_word_forward(p1);
         var p4 = skip_word_forward(cursor_pos);
         var p3 = skip_word_backward(p4);
 
         if (p1 < p2 && p2 <= cursor_pos && cursor_pos <= p3 && p3 < p4) {
             cmd = cmd.substring(0, p1) + cmd.substring(p3, p4) +
             cmd.substring(p2, p3) + cmd.substring(p1, p2);
             cursor_pos = p4;
         }
     }
 
     function upcase_word() {
         var end = skip_word_forward(cursor_pos);
         cmd = cmd.substring(0, cursor_pos) +
             cmd.substring(cursor_pos, end).toUpperCase() +
             cmd.substring(end);
     }
 
     function downcase_word() {
         var end = skip_word_forward(cursor_pos);
         cmd = cmd.substring(0, cursor_pos) +
             cmd.substring(cursor_pos, end).toLowerCase() +
             cmd.substring(end);
     }
 
     function kill_region(start, end, dir) {
         var s = cmd.substring(start, end);
         if (last_fun !== kill_region)
             clip_board = s;
         else if (dir < 0)
             clip_board = s + clip_board;
         else
             clip_board = clip_board + s;
 
         cmd = cmd.substring(0, start) + cmd.substring(end);
         if (cursor_pos > end)
             cursor_pos -= end - start;
         else if (cursor_pos > start)
             cursor_pos = start;
         this_fun = kill_region;
     }
 
     function kill_line() {
         kill_region(cursor_pos, cmd.length, 1);
     }
 
     function backward_kill_line() {
         kill_region(0, cursor_pos, -1);
     }
 
     function kill_word() {
         kill_region(cursor_pos, skip_word_forward(cursor_pos), 1);
     }
 
     function backward_kill_word() {
         kill_region(skip_word_backward(cursor_pos), cursor_pos, -1);
     }
 
     function yank() {
         insert(clip_board);
     }
 
     function control_c() {
         if (last_fun === control_c) {
             std.puts("\n");
             std.exit(0);
         } else {
             std.puts("\n(Press Ctrl-C again to quit)\n");
             reset();
             readline_print_prompt();
         }
     }
 
     function reset() {
         cmd = "";
         cursor_pos = 0;
     }
 
     function get_context_word(line, pos) {
         var s = "";
         while (pos > 0 && is_word(line[pos - 1])) {
             pos--;
             s = line[pos] + s;
         }
         return s;
     }
     function get_context_object(line, pos) {
         var obj, base, c;
         if (pos <= 0 || " ~!%^&*(-+={[|:;,<>?/".indexOf(line[pos - 1]) >= 0)
             return g;
         if (pos >= 2 && line[pos - 1] === ".") {
             pos--;
             obj = {};
             switch (c = line[pos - 1]) {
             case '\'':
             case '\"':
                 return "a";
             case ']':
                 return [];
             case '}':
                 return {};
             case '/':
                 return / /;
             default:
                 if (is_word(c)) {
                     base = get_context_word(line, pos);
                     if (["true", "false", "null", "this"].includes(base) || !isNaN(+base))
                         return eval(base);
                     // Check if `base` is a set of regexp flags
                     if (pos - base.length >= 3 && line[pos - base.length - 1] === '/')
                         return new RegExp('', base);
                     obj = get_context_object(line, pos - base.length);
                     if (obj === null || obj === void 0)
                         return obj;
                     if (obj === g && obj[base] === void 0)
                         return eval(base);
                     else
                         return obj[base];
                 }
                 return {};
             }
         }
         return void 0;
     }
 
     function get_completions(line, pos) {
         var s, obj, ctx_obj, r, i, j, paren;
 
         s = get_context_word(line, pos);
         ctx_obj = get_context_object(line, pos - s.length);
         r = [];
         /* enumerate properties from object and its prototype chain,
            add non-numeric regular properties with s as e prefix
          */
         for (i = 0, obj = ctx_obj; i < 10 && obj !== null && obj !== void 0; i++) {
             var props = Object.getOwnPropertyNames(obj);
             /* add non-numeric regular properties */
             for (j = 0; j < props.length; j++) {
                 var prop = props[j];
                 if (typeof prop == "string" && ""+(+prop) != prop && prop.startsWith(s))
                     r.push(prop);
             }
             obj = Object.getPrototypeOf(obj);
         }
         if (r.length > 1) {
             /* sort list with internal names last and remove duplicates */
             function symcmp(a, b) {
                 if (a[0] != b[0]) {
                     if (a[0] == '_')
                         return 1;
                     if (b[0] == '_')
                         return -1;
                 }
                 if (a < b)
                     return -1;
                 if (a > b)
                     return +1;
                 return 0;
             }
             r.sort(symcmp);
             for(i = j = 1; i < r.length; i++) {
                 if (r[i] != r[i - 1])
                     r[j++] = r[i];
             }
             r.length = j;
         }
         /* 'tab' = list of completions, 'pos' = cursor position inside
            the completions */
         return { tab: r, pos: s.length, ctx: ctx_obj };
     }
 
     function completion() {
         var tab, res, s, i, j, len, t, max_width, col, n_cols, row, n_rows;
         res = get_completions(cmd, cursor_pos);
         tab = res.tab;
         if (tab.length === 0)
             return;
         s = tab[0];
         len = s.length;
         /* add the chars which are identical in all the completions */
         for(i = 1; i < tab.length; i++) {
             t = tab[i];
             for(j = 0; j < len; j++) {
                 if (t[j] !== s[j]) {
                     len = j;
                     break;
                 }
             }
         }
         for(i = res.pos; i < len; i++) {
             insert(s[i]);
         }
         if (last_fun === completion && tab.length == 1) {
             /* append parentheses to function names */
             var m = res.ctx[tab[0]];
             if (typeof m == "function") {
                 insert('(');
                 if (m.length == 0)
                     insert(')');
             } else if (typeof m == "object") {
                 insert('.');
             }
         }
         /* show the possible completions */
         if (last_fun === completion && tab.length >= 2) {
             max_width = 0;
             for(i = 0; i < tab.length; i++)
                 max_width = Math.max(max_width, tab[i].length);
             max_width += 2;
             n_cols = Math.max(1, Math.floor((term_width + 1) / max_width));
             n_rows = Math.ceil(tab.length / n_cols);
             std.puts("\n");
             /* display the sorted list column-wise */
             for (row = 0; row < n_rows; row++) {
                 for (col = 0; col < n_cols; col++) {
                     i = col * n_rows + row;
                     if (i >= tab.length)
                         break;
                     s = tab[i];
                     if (col != n_cols - 1)
                         s = s.padEnd(max_width);
                     std.puts(s);
                 }
                 std.puts("\n");
             }
             /* show a new prompt */
             readline_print_prompt();
         }
     }
 
     var commands = {        /* command table */
         "\x01":     beginning_of_line,      /* ^A - bol */
         "\x02":     backward_char,          /* ^B - backward-char */
         "\x03":     control_c,              /* ^C - abort */
         "\x04":     control_d,              /* ^D - delete-char or exit */
         "\x05":     end_of_line,            /* ^E - eol */
         "\x06":     forward_char,           /* ^F - forward-char */
         "\x07":     abort,                  /* ^G - bell */
         "\x08":     backward_delete_char,   /* ^H - backspace */
         "\x09":     completion,             /* ^I - history-search-backward */
         "\x0a":     accept_line,            /* ^J - newline */
         "\x0b":     kill_line,              /* ^K - delete to end of line */
         "\x0d":     accept_line,            /* ^M - enter */
         "\x0e":     next_history,           /* ^N - down */
         "\x10":     previous_history,       /* ^P - up */
         "\x11":     quoted_insert,          /* ^Q - quoted-insert */
         "\x12":     alert,                  /* ^R - reverse-search */
         "\x13":     alert,                  /* ^S - search */
         "\x14":     transpose_chars,        /* ^T - transpose */
         "\x18":     reset,                  /* ^X - cancel */
         "\x19":     yank,                   /* ^Y - yank */
         "\x1bOA":   previous_history,       /* ^[OA - up */
         "\x1bOB":   next_history,           /* ^[OB - down */
         "\x1bOC":   forward_char,           /* ^[OC - right */
         "\x1bOD":   backward_char,          /* ^[OD - left */
         "\x1bOF":   forward_word,           /* ^[OF - ctrl-right */
         "\x1bOH":   backward_word,          /* ^[OH - ctrl-left */
         "\x1b[1;5C": forward_word,          /* ^[[1;5C - ctrl-right */
         "\x1b[1;5D": backward_word,         /* ^[[1;5D - ctrl-left */
         "\x1b[1~":  beginning_of_line,      /* ^[[1~ - bol */
         "\x1b[3~":  delete_char,            /* ^[[3~ - delete */
         "\x1b[4~":  end_of_line,            /* ^[[4~ - eol */
         "\x1b[5~":  history_search_backward,/* ^[[5~ - page up */
         "\x1b[6~":  history_search_forward, /* ^[[5~ - page down */
         "\x1b[A":   previous_history,       /* ^[[A - up */
         "\x1b[B":   next_history,           /* ^[[B - down */
         "\x1b[C":   forward_char,           /* ^[[C - right */
         "\x1b[D":   backward_char,          /* ^[[D - left */
         "\x1b[F":   end_of_line,            /* ^[[F - end */
         "\x1b[H":   beginning_of_line,      /* ^[[H - home */
         "\x1b\x7f": backward_kill_word,     /* M-C-? - backward_kill_word */
         "\x1bb":    backward_word,          /* M-b - backward_word */
         "\x1bd":    kill_word,              /* M-d - kill_word */
         "\x1bf":    forward_word,           /* M-f - backward_word */
         "\x1bk":    backward_kill_line,     /* M-k - backward_kill_line */
         "\x1bl":    downcase_word,          /* M-l - downcase_word */
         "\x1bt":    transpose_words,        /* M-t - transpose_words */
         "\x1bu":    upcase_word,            /* M-u - upcase_word */
         "\x7f":     backward_delete_char,   /* ^? - delete */
     };
 
     function dupstr(str, count) {
         var res = "";
         while (count-- > 0)
             res += str;
         return res;
     }
 
     var readline_keys;
     var readline_state;
     var readline_cb;
 
     function readline_print_prompt()
     {
         std.puts(prompt);
         term_cursor_x = ucs_length(prompt) % term_width;
         last_cmd = "";
         last_cursor_pos = 0;
     }
 
     function readline_start(defstr, cb) {
         cmd = defstr || "";
         cursor_pos = cmd.length;
         history_index = history.length;
         readline_cb = cb;
 
         prompt = pstate;
 
         if (mexpr) {
             prompt += dupstr(" ", plen - prompt.length);
             prompt += ps2;
         } else {
             if (show_time) {
                 var t = eval_time / 1000;
                 prompt += t.toFixed(6) + " ";
             }
             plen = prompt.length;
             prompt += ps1;
         }
         readline_print_prompt();
         update();
         readline_state = 0;
     }
 
     function handle_char(c1) {
         var c;
         c = String.fromCodePoint(c1);
         switch(readline_state) {
         case 0:
             if (c == '\x1b') {  /* '^[' - ESC */
                 readline_keys = c;
                 readline_state = 1;
             } else {
                 handle_key(c);
             }
             break;
         case 1: /* '^[ */
             readline_keys += c;
             if (c == '[') {
                 readline_state = 2;
             } else if (c == 'O') {
                 readline_state = 3;
             } else {
                 handle_key(readline_keys);
                 readline_state = 0;
             }
             break;
         case 2: /* '^[[' - CSI */
             readline_keys += c;
             if (!(c == ';' || (c >= '0' && c <= '9'))) {
                 handle_key(readline_keys);
                 readline_state = 0;
             }
             break;
         case 3: /* '^[O' - ESC2 */
             readline_keys += c;
             handle_key(readline_keys);
             readline_state = 0;
             break;
         }
     }
 
     function handle_key(keys) {
         var fun;
 
         if (quote_flag) {
             if (ucs_length(keys) === 1)
                 insert(keys);
             quote_flag = false;
         } else if (fun = commands[keys]) {
             this_fun = fun;
             switch (fun(keys)) {
             case -1:
                 readline_cb(cmd);
                 return;
             case -2:
                 readline_cb(null);
                 return;
             case -3:
                 /* uninstall a Ctrl-C signal handler */
                 os.signal(os.SIGINT, null);
                 /* uninstall the stdin read handler */
                 os.setReadHandler(term_fd, null);
                 return;
             }
             last_fun = this_fun;
         } else if (ucs_length(keys) === 1 && keys >= ' ') {
             insert(keys);
             last_fun = insert;
         } else {
             alert(); /* beep! */
         }
 
         cursor_pos = (cursor_pos < 0) ? 0 :
             (cursor_pos > cmd.length) ? cmd.length : cursor_pos;
         update();
     }
 
     var hex_mode = false;
 
     function number_to_string_hex(a) {
         var s;
         if (a < 0) {
             a = -a;
             s = "-";
         } else {
             s = "";
         }
         s += "0x" + a.toString(16);
         return s;
     }
     
     function extract_directive(a) {
         var pos;
         if (a[0] !== '\\')
             return "";
         for (pos = 1; pos < a.length; pos++) {
             if (!is_alpha(a[pos]))
                 break;
         }
         return a.substring(1, pos);
     }
 
     /* return true if the string after cmd can be evaluted as JS */
     function handle_directive(cmd, expr) {
         var param, prec1, expBits1;
 
         if (cmd === "h" || cmd === "?" || cmd == "help") {
             help();
         } else if (cmd === "load") {
             var filename = expr.substring(cmd.length + 1).trim();
             if (filename.lastIndexOf(".") <= filename.lastIndexOf("/"))
                 filename += ".js";
             std.loadScript(filename);
             return false;
         } else if (cmd === "x") {
             hex_mode = true;
         } else if (cmd === "d") {
             hex_mode = false;
         } else if (cmd === "t") {
             show_time = !show_time;
         } else if (cmd === "clear") {
             std.puts("\x1b[H\x1b[J");
         } else if (cmd === "q") {
             std.exit(0);
         } else {
             std.puts("Unknown directive: " + cmd + "\n");
             return false;
         }
         return true;
     }
 
     function help() {
         function sel(n) {
             return n ? "*": " ";
         }
         std.puts("\\h          this help\n" +
                  "\\x         " + sel(hex_mode) + "hexadecimal number display\n" +
                  "\\d         " + sel(!hex_mode) + "decimal number display\n" +
                  "\\t         " + sel(show_time) + "toggle timing display\n" +
                   "\\clear      clear the terminal\n" +
                  "\\q          exit\n");
     }
 
     function cmd_start() {
         std.puts('QuickJS - Type "\\h" for help\n');
 
         cmd_readline_start();
     }
 
     function cmd_readline_start() {
         readline_start(dupstr("    ", level), readline_handle_cmd);
     }
 
     function readline_handle_cmd(expr) {
         if (!handle_cmd(expr)) {
             cmd_readline_start();
         }
     }
 
     /* return true if async termination */
     function handle_cmd(expr) {
         var colorstate, cmd;
 
         if (expr === null) {
             expr = "";
             return false;
         }
         if (expr === "?") {
             help();
             return false;
         }
         cmd = extract_directive(expr);
         if (cmd.length > 0) {
             if (!handle_directive(cmd, expr)) {
                 return false;
             }
             expr = expr.substring(cmd.length + 1);
         }
         if (expr === "")
             return false;
 
         if (mexpr)
             expr = mexpr + '\n' + expr;
         colorstate = colorize_js(expr);
         pstate = colorstate[0];
         level = colorstate[1];
         if (pstate) {
             mexpr = expr;
             return false;
         }
         mexpr = "";
 
         eval_and_print_start(expr);
 
         return true;
     }
 
     function eval_and_print_start(expr) {
         var result;
 
         try {
             eval_start_time = os.now();
             /* eval as a script */
             result = std.evalScript(expr, { backtrace_barrier: true, async: true });
             /* result is a promise */
             result.then(print_eval_result, print_eval_error);
         } catch (error) {
             print_eval_error(error);
         }
     }
 
     function print_eval_result(result) {
         var default_print = true;
 
         result = result.value;
         eval_time = os.now() - eval_start_time;
         std.puts(colors[styles.result]);
         if (hex_mode) {
             if (typeof result == "number" &&
                 result === Math.floor(result)) {
                 std.puts(number_to_string_hex(result));
                 default_print = false;
             } else if (typeof result == "bigint") {
                 std.puts(number_to_string_hex(result));
                 std.puts("n");
                 default_print = false;
             }
         }
         if (default_print) {
             std.__printObject(result);
         }
         std.puts("\n");
         std.puts(colors.none);
         /* set the last result */
         g._ = result;
 
         handle_cmd_end();
     }
 
     function print_eval_error(error) {
         std.puts(colors[styles.error_msg]);
         if (!(error instanceof Error))
             std.puts("Throw: ");
         std.__printObject(error);
         std.puts("\n");
         std.puts(colors.none);
 
         handle_cmd_end();
     }
 
     function handle_cmd_end() {
         level = 0;
         /* run the garbage collector after each command */
         std.gc();
         cmd_readline_start();
     }
 
     function colorize_js(str) {
         var i, c, start, n = str.length;
         var style, state = "", level = 0;
         var primary, can_regex = 1;
         var r = [];
 
         function push_state(c) { state += c; }
         function last_state(c) { return state.substring(state.length - 1); }
         function pop_state(c) {
             var c = last_state();
             state = state.substring(0, state.length - 1);
             return c;
         }
 
         function parse_block_comment() {
             style = 'comment';
             push_state('/');
             for (i++; i < n - 1; i++) {
                 if (str[i] == '*' && str[i + 1] == '/') {
                     i += 2;
                     pop_state('/');
                     break;
                 }
             }
         }
 
         function parse_line_comment() {
             style = 'comment';
             for (i++; i < n; i++) {
                 if (str[i] == '\n') {
                     break;
                 }
             }
         }
 
         function parse_string(delim) {
             style = 'string';
             push_state(delim);
             while (i < n) {
                 c = str[i++];
                 if (c == '\n') {
                     style = 'error';
                     continue;
                 }
                 if (c == '\\') {
                     if (i >= n)
                         break;
                     i++;
                 } else
                 if (c == delim) {
                     pop_state();
                     break;
                 }
             }
         }
 
         function parse_regex() {
             style = 'regex';
             push_state('/');
             while (i < n) {
                 c = str[i++];
                 if (c == '\n') {
                     style = 'error';
                     continue;
                 }
                 if (c == '\\') {
                     if (i < n) {
                         i++;
                     }
                     continue;
                 }
                 if (last_state() == '[') {
                     if (c == ']') {
                         pop_state()
                     }
                     // ECMA 5: ignore '/' inside char classes
                     continue;
                 }
                 if (c == '[') {
                     push_state('[');
                     if (str[i] == '[' || str[i] == ']')
                         i++;
                     continue;
                 }
                 if (c == '/') {
                     pop_state();
                     while (i < n && is_word(str[i]))
                         i++;
                     break;
                 }
             }
         }
 
         function parse_number() {
             style = 'number';
             while (i < n && (is_word(str[i]) || (str[i] == '.' && (i == n - 1 || str[i + 1] != '.')))) {
                 i++;
             }
         }
 
         var js_keywords = "|" +
             "break|case|catch|continue|debugger|default|delete|do|" +
             "else|finally|for|function|if|in|instanceof|new|" +
             "return|switch|this|throw|try|typeof|while|with|" +
             "class|const|enum|import|export|extends|super|" +
             "implements|interface|let|package|private|protected|" +
             "public|static|yield|" +
             "undefined|null|true|false|Infinity|NaN|" +
             "eval|arguments|" +
             "await|";
 
         var js_no_regex = "|this|super|undefined|null|true|false|Infinity|NaN|arguments|";
         var js_types = "|void|var|";
 
         function parse_identifier() {
             can_regex = 1;
 
             while (i < n && is_word(str[i]))
                 i++;
 
             var w = '|' + str.substring(start, i) + '|';
 
             if (js_keywords.indexOf(w) >= 0) {
                 style = 'keyword';
                 if (js_no_regex.indexOf(w) >= 0)
                     can_regex = 0;
                 return;
             }
 
             var i1 = i;
             while (i1 < n && str[i1] == ' ')
                 i1++;
 
             if (i1 < n && str[i1] == '(') {
                 style = 'function';
                 return;
             }
 
             if (js_types.indexOf(w) >= 0) {
                 style = 'type';
                 return;
             }
 
             style = 'identifier';
             can_regex = 0;
         }
 
         function set_style(from, to) {
             while (r.length < from)
                 r.push('default');
             while (r.length < to)
                 r.push(style);
         }
 
         for (i = 0; i < n;) {
             style = null;
             start = i;
             switch (c = str[i++]) {
             case ' ':
             case '\t':
             case '\r':
             case '\n':
                 continue;
             case '+':
             case '-':
                 if (i < n && str[i] == c) {
                     i++;
                     continue;
                 }
                 can_regex = 1;
                 continue;
             case '/':
                 if (i < n && str[i] == '*') { // block comment
                     parse_block_comment();
                     break;
                 }
                 if (i < n && str[i] == '/') { // line comment
                     parse_line_comment();
                     break;
                 }
                 if (can_regex) {
                     parse_regex();
                     can_regex = 0;
                     break;
                 }
                 can_regex = 1;
                 continue;
             case '\'':
             case '\"':
             case '`':
                 parse_string(c);
                 can_regex = 0;
                 break;
             case '(':
             case '[':
             case '{':
                 can_regex = 1;
                 level++;
                 push_state(c);
                 continue;
             case ')':
             case ']':
             case '}':
                 can_regex = 0;
                 if (level > 0 && is_balanced(last_state(), c)) {
                     level--;
                     pop_state();
                     continue;
                 }
                 style = 'error';
                 break;
             default:
                 if (is_digit(c)) {
                     parse_number();
                     can_regex = 0;
                     break;
                 }
                 if (is_word(c) || c == '$') {
                     parse_identifier();
                     break;
                 }
                 can_regex = 1;
                 continue;
             }
             if (style)
                 set_style(start, i);
         }
         set_style(n, n);
         return [ state, level, r ];
     }
 
     termInit();
 
     cmd_start();
 
 })(globalThis);