/src/mupdf/thirdparty/mujs/jslex.c

Source
#include "jsi.h"
#include "utf.h"

JS_NORETURN static void jsY_error(js_State *J, const char *fmt, ...) JS_PRINTFLIKE(2,3);

static void jsY_error(js_State *J, const char *fmt, ...)
{
  va_list ap;
  char buf[512];
  char msgbuf[256];

  va_start(ap, fmt);
  vsnprintf(msgbuf, 256, fmt, ap);
  va_end(ap);

  snprintf(buf, 256, "%s:%d: ", J->filename, J->lexline);
  strcat(buf, msgbuf);

  js_newsyntaxerror(J, buf);
  js_throw(J);
}

static const char *tokenstring[] = {
  "(end-of-file)",
  "'\\x01'", "'\\x02'", "'\\x03'", "'\\x04'", "'\\x05'", "'\\x06'", "'\\x07'",
  "'\\x08'", "'\\x09'", "'\\x0A'", "'\\x0B'", "'\\x0C'", "'\\x0D'", "'\\x0E'", "'\\x0F'",
  "'\\x10'", "'\\x11'", "'\\x12'", "'\\x13'", "'\\x14'", "'\\x15'", "'\\x16'", "'\\x17'",
  "'\\x18'", "'\\x19'", "'\\x1A'", "'\\x1B'", "'\\x1C'", "'\\x1D'", "'\\x1E'", "'\\x1F'",
  "' '", "'!'", "'\"'", "'#'", "'$'", "'%'", "'&'", "'\\''",
  "'('", "')'", "'*'", "'+'", "','", "'-'", "'.'", "'/'",
  "'0'", "'1'", "'2'", "'3'", "'4'", "'5'", "'6'", "'7'",
  "'8'", "'9'", "':'", "';'", "'<'", "'='", "'>'", "'?'",
  "'@'", "'A'", "'B'", "'C'", "'D'", "'E'", "'F'", "'G'",
  "'H'", "'I'", "'J'", "'K'", "'L'", "'M'", "'N'", "'O'",
  "'P'", "'Q'", "'R'", "'S'", "'T'", "'U'", "'V'", "'W'",
  "'X'", "'Y'", "'Z'", "'['", "'\'", "']'", "'^'", "'_'",
  "'`'", "'a'", "'b'", "'c'", "'d'", "'e'", "'f'", "'g'",
  "'h'", "'i'", "'j'", "'k'", "'l'", "'m'", "'n'", "'o'",
  "'p'", "'q'", "'r'", "'s'", "'t'", "'u'", "'v'", "'w'",
  "'x'", "'y'", "'z'", "'{'", "'|'", "'}'", "'~'", "'\\x7F'",

  0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
  0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
  0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
  0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
  0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
  0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
  0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
  0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,

  "(identifier)", "(number)", "(string)", "(regexp)",

  "'<='", "'>='", "'=='", "'!='", "'==='", "'!=='",
  "'<<'", "'>>'", "'>>>'", "'&&'", "'||'",
  "'+='", "'-='", "'*='", "'/='", "'%='",
  "'<<='", "'>>='", "'>>>='", "'&='", "'|='", "'^='",
  "'++'", "'--'",

  "'break'", "'case'", "'catch'", "'continue'", "'debugger'",
  "'default'", "'delete'", "'do'", "'else'", "'false'", "'finally'", "'for'",
  "'function'", "'if'", "'in'", "'instanceof'", "'new'", "'null'", "'return'",
  "'switch'", "'this'", "'throw'", "'true'", "'try'", "'typeof'", "'var'",
  "'void'", "'while'", "'with'",
};

const char *jsY_tokenstring(int token)
{
  if (token >= 0 && token < (int)nelem(tokenstring))
    if (tokenstring[token])
      return tokenstring[token];
  return "<unknown>";
}

static const char *keywords[] = {
  "break", "case", "catch", "continue", "debugger", "default", "delete",
  "do", "else", "false", "finally", "for", "function", "if", "in",
  "instanceof", "new", "null", "return", "switch", "this", "throw",
  "true", "try", "typeof", "var", "void", "while", "with",
};

int jsY_findword(const char *s, const char **list, int num)
{
  int l = 0;
  int r = num - 1;
  while (l <= r) {
    int m = (l + r) >> 1;
    int c = strcmp(s, list[m]);
    if (c < 0)
      r = m - 1;
    else if (c > 0)
      l = m + 1;
    else
      return m;
  }
  return -1;
}

static int jsY_findkeyword(js_State *J, const char *s)
{
  int i = jsY_findword(s, keywords, nelem(keywords));
  if (i >= 0) {
    J->text = keywords[i];
    return TK_BREAK + i; /* first keyword + i */
  }
  J->text = s;
  return TK_IDENTIFIER;
}

int jsY_iswhite(int c)
{
  return c == 0x9 || c == 0xB || c == 0xC || c == 0x20 || c == 0xA0 || c == 0xFEFF;
}

int jsY_isnewline(int c)
{
  return c == 0xA || c == 0xD || c == 0x2028 || c == 0x2029;
}

#ifndef isalpha
#define isalpha(c) ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
#endif
#ifndef isdigit
#define isdigit(c) (c >= '0' && c <= '9')
#endif
#ifndef ishex
#define ishex(c) ((c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'))
#endif

static int jsY_isidentifierstart(int c)
{
  return isalpha(c) || c == '$' || c == '_' || isalpharune(c);
}

static int jsY_isidentifierpart(int c)
{
  return isdigit(c) || isalpha(c) || c == '$' || c == '_' || isalpharune(c);
}

static int jsY_isdec(int c)
{
  return isdigit(c);
}

int jsY_ishex(int c)
{
  return isdigit(c) || ishex(c);
}

int jsY_tohex(int c)
{
  if (c >= '0' && c <= '9') return c - '0';
  if (c >= 'a' && c <= 'f') return c - 'a' + 0xA;
  if (c >= 'A' && c <= 'F') return c - 'A' + 0xA;
  return 0;
}

static void jsY_next(js_State *J)
{
  Rune c;
  if (*J->source == 0) {
    J->lexchar = EOF;
    return;
  }
  J->source += chartorune(&c, J->source);
  /* consume CR LF as one unit */
  if (c == '\r' && *J->source == '\n')
    ++J->source;
  if (jsY_isnewline(c)) {
    J->line++;
    c = '\n';
  }
  J->lexchar = c;
}

#define jsY_accept(J, x) (J->lexchar == x ? (jsY_next(J), 1) : 0)

#define jsY_expect(J, x) if (!jsY_accept(J, x)) jsY_error(J, "expected '%c'", x)

static void jsY_unescape(js_State *J)
{
  if (jsY_accept(J, '\\')) {
    if (jsY_accept(J, 'u')) {
      int x = 0;
      if (!jsY_ishex(J->lexchar)) { goto error; } x |= jsY_tohex(J->lexchar) << 12; jsY_next(J);
      if (!jsY_ishex(J->lexchar)) { goto error; } x |= jsY_tohex(J->lexchar) << 8; jsY_next(J);
      if (!jsY_ishex(J->lexchar)) { goto error; } x |= jsY_tohex(J->lexchar) << 4; jsY_next(J);
      if (!jsY_ishex(J->lexchar)) { goto error; } x |= jsY_tohex(J->lexchar);
      J->lexchar = x;
      return;
    }
error:
    jsY_error(J, "unexpected escape sequence");
  }
}

static void textinit(js_State *J)
{
  if (!J->lexbuf.text) {
    J->lexbuf.cap = 4096;
    J->lexbuf.text = js_malloc(J, J->lexbuf.cap);
  }
  J->lexbuf.len = 0;
}

static void textpush(js_State *J, Rune c)
{
  int n, newcap;
  if (c == EOF)
    n = 1;
  else
    n = runelen(c);
  if (J->lexbuf.len + n > J->lexbuf.cap) {
    newcap = J->lexbuf.cap * 2;
    J->lexbuf.text = js_realloc(J, J->lexbuf.text, J->lexbuf.cap);
    J->lexbuf.cap = newcap;
  }
  if (c == EOF)
    J->lexbuf.text[J->lexbuf.len++] = 0;
  else
    J->lexbuf.len += runetochar(J->lexbuf.text + J->lexbuf.len, &c);
}

static char *textend(js_State *J)
{
  textpush(J, EOF);
  return J->lexbuf.text;
}

static void lexlinecomment(js_State *J)
{
  while (J->lexchar != EOF && J->lexchar != '\n')
    jsY_next(J);
}

static int lexcomment(js_State *J)
{
  /* already consumed initial '/' '*' sequence */
  while (J->lexchar != EOF) {
    if (jsY_accept(J, '*')) {
      while (J->lexchar == '*')
        jsY_next(J);
      if (jsY_accept(J, '/'))
        return 0;
    }
    else
      jsY_next(J);
  }
  return -1;
}

static double lexhex(js_State *J)
{
  double n = 0;
  if (!jsY_ishex(J->lexchar))
    jsY_error(J, "malformed hexadecimal number");
  while (jsY_ishex(J->lexchar)) {
    n = n * 16 + jsY_tohex(J->lexchar);
    jsY_next(J);
  }
  return n;
}

#if 0

static double lexinteger(js_State *J)
{
  double n = 0;
  if (!jsY_isdec(J->lexchar))
    jsY_error(J, "malformed number");
  while (jsY_isdec(J->lexchar)) {
    n = n * 10 + (J->lexchar - '0');
    jsY_next(J);
  }
  return n;
}

static double lexfraction(js_State *J)
{
  double n = 0;
  double d = 1;
  while (jsY_isdec(J->lexchar)) {
    n = n * 10 + (J->lexchar - '0');
    d = d * 10;
    jsY_next(J);
  }
  return n / d;
}

static double lexexponent(js_State *J)
{
  double sign;
  if (jsY_accept(J, 'e') || jsY_accept(J, 'E')) {
    if (jsY_accept(J, '-')) sign = -1;
    else if (jsY_accept(J, '+')) sign = 1;
    else sign = 1;
    return sign * lexinteger(J);
  }
  return 0;
}

static int lexnumber(js_State *J)
{
  double n;
  double e;

  if (jsY_accept(J, '0')) {
    if (jsY_accept(J, 'x') || jsY_accept(J, 'X')) {
      J->number = lexhex(J);
      return TK_NUMBER;
    }
    if (jsY_isdec(J->lexchar))
      jsY_error(J, "number with leading zero");
    n = 0;
    if (jsY_accept(J, '.'))
      n += lexfraction(J);
  } else if (jsY_accept(J, '.')) {
    if (!jsY_isdec(J->lexchar))
      return '.';
    n = lexfraction(J);
  } else {
    n = lexinteger(J);
    if (jsY_accept(J, '.'))
      n += lexfraction(J);
  }

  e = lexexponent(J);
  if (e < 0)
    n /= pow(10, -e);
  else if (e > 0)
    n *= pow(10, e);

  if (jsY_isidentifierstart(J->lexchar))
    jsY_error(J, "number with letter suffix");

  J->number = n;
  return TK_NUMBER;
}

#else

static int lexnumber(js_State *J)
{
  const char *s = J->source - 1;

  if (jsY_accept(J, '0')) {
    if (jsY_accept(J, 'x') || jsY_accept(J, 'X')) {
      J->number = lexhex(J);
      return TK_NUMBER;
    }
    if (jsY_isdec(J->lexchar))
      jsY_error(J, "number with leading zero");
    if (jsY_accept(J, '.')) {
      while (jsY_isdec(J->lexchar))
        jsY_next(J);
    }
  } else if (jsY_accept(J, '.')) {
    if (!jsY_isdec(J->lexchar))
      return '.';
    while (jsY_isdec(J->lexchar))
      jsY_next(J);
  } else {
    while (jsY_isdec(J->lexchar))
      jsY_next(J);
    if (jsY_accept(J, '.')) {
      while (jsY_isdec(J->lexchar))
        jsY_next(J);
    }
  }

  if (jsY_accept(J, 'e') || jsY_accept(J, 'E')) {
    if (J->lexchar == '-' || J->lexchar == '+')
      jsY_next(J);
    if (jsY_isdec(J->lexchar))
      while (jsY_isdec(J->lexchar))
        jsY_next(J);
    else
      jsY_error(J, "missing exponent");
  }

  if (jsY_isidentifierstart(J->lexchar))
    jsY_error(J, "number with letter suffix");

  J->number = js_strtod(s, NULL);
  return TK_NUMBER;
}

#endif

static int lexescape(js_State *J)
{
  int x = 0;

  /* already consumed '\' */

  if (jsY_accept(J, '\n'))
    return 0;

  switch (J->lexchar) {
  case EOF: jsY_error(J, "unterminated escape sequence");
  case 'u':
    jsY_next(J);
    if (!jsY_ishex(J->lexchar)) return 1; else { x |= jsY_tohex(J->lexchar) << 12; jsY_next(J); }
    if (!jsY_ishex(J->lexchar)) return 1; else { x |= jsY_tohex(J->lexchar) << 8; jsY_next(J); }
    if (!jsY_ishex(J->lexchar)) return 1; else { x |= jsY_tohex(J->lexchar) << 4; jsY_next(J); }
    if (!jsY_ishex(J->lexchar)) return 1; else { x |= jsY_tohex(J->lexchar); jsY_next(J); }
    textpush(J, x);
    break;
  case 'x':
    jsY_next(J);
    if (!jsY_ishex(J->lexchar)) return 1; else { x |= jsY_tohex(J->lexchar) << 4; jsY_next(J); }
    if (!jsY_ishex(J->lexchar)) return 1; else { x |= jsY_tohex(J->lexchar); jsY_next(J); }
    textpush(J, x);
    break;
  case '0': textpush(J, 0); jsY_next(J); break;
  case '\\': textpush(J, '\\'); jsY_next(J); break;
  case '\'': textpush(J, '\''); jsY_next(J); break;
  case '"': textpush(J, '"'); jsY_next(J); break;
  case 'b': textpush(J, '\b'); jsY_next(J); break;
  case 'f': textpush(J, '\f'); jsY_next(J); break;
  case 'n': textpush(J, '\n'); jsY_next(J); break;
  case 'r': textpush(J, '\r'); jsY_next(J); break;
  case 't': textpush(J, '\t'); jsY_next(J); break;
  case 'v': textpush(J, '\v'); jsY_next(J); break;
  default: textpush(J, J->lexchar); jsY_next(J); break;
  }
  return 0;
}

static int lexstring(js_State *J)
{
  const char *s;

  int q = J->lexchar;
  jsY_next(J);

  textinit(J);

  while (J->lexchar != q) {
    if (J->lexchar == EOF || J->lexchar == '\n')
      jsY_error(J, "string not terminated");
    if (jsY_accept(J, '\\')) {
      if (lexescape(J))
        jsY_error(J, "malformed escape sequence");
    } else {
      textpush(J, J->lexchar);
      jsY_next(J);
    }
  }
  jsY_expect(J, q);

  s = textend(J);

  J->text = s;
  return TK_STRING;
}

/* the ugliest language wart ever... */
static int isregexpcontext(int last)
{
  switch (last) {
  case ']':
  case ')':
  case '}':
  case TK_IDENTIFIER:
  case TK_NUMBER:
  case TK_STRING:
  case TK_FALSE:
  case TK_NULL:
  case TK_THIS:
  case TK_TRUE:
    return 0;
  default:
    return 1;
  }
}

static int lexregexp(js_State *J)
{
  const char *s;
  int g, m, i;
  int inclass = 0;

  /* already consumed initial '/' */

  textinit(J);

  /* regexp body */
  while (J->lexchar != '/' || inclass) {
    if (J->lexchar == EOF || J->lexchar == '\n') {
      jsY_error(J, "regular expression not terminated");
    } else if (jsY_accept(J, '\\')) {
      if (jsY_accept(J, '/')) {
        textpush(J, '/');
      } else {
        textpush(J, '\\');
        if (J->lexchar == EOF || J->lexchar == '\n')
          jsY_error(J, "regular expression not terminated");
        textpush(J, J->lexchar);
        jsY_next(J);
      }
    } else {
      if (J->lexchar == '[' && !inclass)
        inclass = 1;
      if (J->lexchar == ']' && inclass)
        inclass = 0;
      textpush(J, J->lexchar);
      jsY_next(J);
    }
  }
  jsY_expect(J, '/');

  s = textend(J);

  /* regexp flags */
  g = i = m = 0;

  while (jsY_isidentifierpart(J->lexchar)) {
    if (jsY_accept(J, 'g')) ++g;
    else if (jsY_accept(J, 'i')) ++i;
    else if (jsY_accept(J, 'm')) ++m;
    else jsY_error(J, "illegal flag in regular expression: %c", J->lexchar);
  }

  if (g > 1 || i > 1 || m > 1)
    jsY_error(J, "duplicated flag in regular expression");

  J->text = s;
  J->number = 0;
  if (g) J->number += JS_REGEXP_G;
  if (i) J->number += JS_REGEXP_I;
  if (m) J->number += JS_REGEXP_M;
  return TK_REGEXP;
}

/* simple "return [no Line Terminator here] ..." contexts */
static int isnlthcontext(int last)
{
  switch (last) {
  case TK_BREAK:
  case TK_CONTINUE:
  case TK_RETURN:
  case TK_THROW:
    return 1;
  default:
    return 0;
  }
}

static int jsY_lexx(js_State *J)
{
  J->newline = 0;

  while (1) {
    J->lexline = J->line; /* save location of beginning of token */

    while (jsY_iswhite(J->lexchar))
      jsY_next(J);

    if (jsY_accept(J, '\n')) {
      J->newline = 1;
      if (isnlthcontext(J->lasttoken))
        return ';';
      continue;
    }

    if (jsY_accept(J, '/')) {
      if (jsY_accept(J, '/')) {
        lexlinecomment(J);
        continue;
      } else if (jsY_accept(J, '*')) {
        if (lexcomment(J))
          jsY_error(J, "multi-line comment not terminated");
        continue;
      } else if (isregexpcontext(J->lasttoken)) {
        return lexregexp(J);
      } else if (jsY_accept(J, '=')) {
        return TK_DIV_ASS;
      } else {
        return '/';
      }
    }

    if (J->lexchar >= '0' && J->lexchar <= '9') {
      return lexnumber(J);
    }

    switch (J->lexchar) {
    case '(': jsY_next(J); return '(';
    case ')': jsY_next(J); return ')';
    case ',': jsY_next(J); return ',';
    case ':': jsY_next(J); return ':';
    case ';': jsY_next(J); return ';';
    case '?': jsY_next(J); return '?';
    case '[': jsY_next(J); return '[';
    case ']': jsY_next(J); return ']';
    case '{': jsY_next(J); return '{';
    case '}': jsY_next(J); return '}';
    case '~': jsY_next(J); return '~';

    case '\'':
    case '"':
      return lexstring(J);

    case '.':
      return lexnumber(J);

    case '<':
      jsY_next(J);
      if (jsY_accept(J, '<')) {
        if (jsY_accept(J, '='))
          return TK_SHL_ASS;
        return TK_SHL;
      }
      if (jsY_accept(J, '='))
        return TK_LE;
      return '<';

    case '>':
      jsY_next(J);
      if (jsY_accept(J, '>')) {
        if (jsY_accept(J, '>')) {
          if (jsY_accept(J, '='))
            return TK_USHR_ASS;
          return TK_USHR;
        }
        if (jsY_accept(J, '='))
          return TK_SHR_ASS;
        return TK_SHR;
      }
      if (jsY_accept(J, '='))
        return TK_GE;
      return '>';

    case '=':
      jsY_next(J);
      if (jsY_accept(J, '=')) {
        if (jsY_accept(J, '='))
          return TK_STRICTEQ;
        return TK_EQ;
      }
      return '=';

    case '!':
      jsY_next(J);
      if (jsY_accept(J, '=')) {
        if (jsY_accept(J, '='))
          return TK_STRICTNE;
        return TK_NE;
      }
      return '!';

    case '+':
      jsY_next(J);
      if (jsY_accept(J, '+'))
        return TK_INC;
      if (jsY_accept(J, '='))
        return TK_ADD_ASS;
      return '+';

    case '-':
      jsY_next(J);
      if (jsY_accept(J, '-'))
        return TK_DEC;
      if (jsY_accept(J, '='))
        return TK_SUB_ASS;
      return '-';

    case '*':
      jsY_next(J);
      if (jsY_accept(J, '='))
        return TK_MUL_ASS;
      return '*';

    case '%':
      jsY_next(J);
      if (jsY_accept(J, '='))
        return TK_MOD_ASS;
      return '%';

    case '&':
      jsY_next(J);
      if (jsY_accept(J, '&'))
        return TK_AND;
      if (jsY_accept(J, '='))
        return TK_AND_ASS;
      return '&';

    case '|':
      jsY_next(J);
      if (jsY_accept(J, '|'))
        return TK_OR;
      if (jsY_accept(J, '='))
        return TK_OR_ASS;
      return '|';

    case '^':
      jsY_next(J);
      if (jsY_accept(J, '='))
        return TK_XOR_ASS;
      return '^';

    case EOF:
      return 0; /* EOF */
    }

    /* Handle \uXXXX escapes in identifiers */
    jsY_unescape(J);
    if (jsY_isidentifierstart(J->lexchar)) {
      textinit(J);
      textpush(J, J->lexchar);

      jsY_next(J);
      jsY_unescape(J);
      while (jsY_isidentifierpart(J->lexchar)) {
        textpush(J, J->lexchar);
        jsY_next(J);
        jsY_unescape(J);
      }

      textend(J);

      return jsY_findkeyword(J, J->lexbuf.text);
    }

    if (J->lexchar >= 0x20 && J->lexchar <= 0x7E)
      jsY_error(J, "unexpected character: '%c'", J->lexchar);
    jsY_error(J, "unexpected character: \\u%04X", J->lexchar);
  }
}

void jsY_initlex(js_State *J, const char *filename, const char *source)
{
  J->filename = filename;
  J->source = source;
  J->line = 1;
  J->lasttoken = 0;
  jsY_next(J); /* load first lookahead character */
}

int jsY_lex(js_State *J)
{
  return J->lasttoken = jsY_lexx(J);
}

static int lexjsonnumber(js_State *J)
{
  const char *s = J->source - 1;

  if (J->lexchar == '-')
    jsY_next(J);

  if (J->lexchar == '0')
    jsY_next(J);
  else if (J->lexchar >= '1' && J->lexchar <= '9')
    while (isdigit(J->lexchar))
      jsY_next(J);
  else
    jsY_error(J, "unexpected non-digit");

  if (jsY_accept(J, '.')) {
    if (isdigit(J->lexchar))
      while (isdigit(J->lexchar))
        jsY_next(J);
    else
      jsY_error(J, "missing digits after decimal point");
  }

  if (jsY_accept(J, 'e') || jsY_accept(J, 'E')) {
    if (J->lexchar == '-' || J->lexchar == '+')
      jsY_next(J);
    if (isdigit(J->lexchar))
      while (isdigit(J->lexchar))
        jsY_next(J);
    else
      jsY_error(J, "missing digits after exponent indicator");
  }

  J->number = js_strtod(s, NULL);
  return TK_NUMBER;
}

static int lexjsonescape(js_State *J)
{
  int x = 0;

  /* already consumed '\' */

  switch (J->lexchar) {
  default: jsY_error(J, "invalid escape sequence");
  case 'u':
    jsY_next(J);
    if (!jsY_ishex(J->lexchar)) return 1; else { x |= jsY_tohex(J->lexchar) << 12; jsY_next(J); }
    if (!jsY_ishex(J->lexchar)) return 1; else { x |= jsY_tohex(J->lexchar) << 8; jsY_next(J); }
    if (!jsY_ishex(J->lexchar)) return 1; else { x |= jsY_tohex(J->lexchar) << 4; jsY_next(J); }
    if (!jsY_ishex(J->lexchar)) return 1; else { x |= jsY_tohex(J->lexchar); jsY_next(J); }
    textpush(J, x);
    break;
  case '"': textpush(J, '"'); jsY_next(J); break;
  case '\\': textpush(J, '\\'); jsY_next(J); break;
  case '/': textpush(J, '/'); jsY_next(J); break;
  case 'b': textpush(J, '\b'); jsY_next(J); break;
  case 'f': textpush(J, '\f'); jsY_next(J); break;
  case 'n': textpush(J, '\n'); jsY_next(J); break;
  case 'r': textpush(J, '\r'); jsY_next(J); break;
  case 't': textpush(J, '\t'); jsY_next(J); break;
  }
  return 0;
}

static int lexjsonstring(js_State *J)
{
  const char *s;

  textinit(J);

  while (J->lexchar != '"') {
    if (J->lexchar == EOF)
      jsY_error(J, "unterminated string");
    else if (J->lexchar < 32)
      jsY_error(J, "invalid control character in string");
    else if (jsY_accept(J, '\\'))
      lexjsonescape(J);
    else {
      textpush(J, J->lexchar);
      jsY_next(J);
    }
  }
  jsY_expect(J, '"');

  s = textend(J);

  J->text = s;
  return TK_STRING;
}

int jsY_lexjson(js_State *J)
{
  while (1) {
    J->lexline = J->line; /* save location of beginning of token */

    while (jsY_iswhite(J->lexchar) || J->lexchar == '\n')
      jsY_next(J);

    if ((J->lexchar >= '0' && J->lexchar <= '9') || J->lexchar == '-')
      return lexjsonnumber(J);

    switch (J->lexchar) {
    case ',': jsY_next(J); return ',';
    case ':': jsY_next(J); return ':';
    case '[': jsY_next(J); return '[';
    case ']': jsY_next(J); return ']';
    case '{': jsY_next(J); return '{';
    case '}': jsY_next(J); return '}';

    case '"':
      jsY_next(J);
      return lexjsonstring(J);

    case 'f':
      jsY_next(J); jsY_expect(J, 'a'); jsY_expect(J, 'l'); jsY_expect(J, 's'); jsY_expect(J, 'e');
      return TK_FALSE;

    case 'n':
      jsY_next(J); jsY_expect(J, 'u'); jsY_expect(J, 'l'); jsY_expect(J, 'l');
      return TK_NULL;

    case 't':
      jsY_next(J); jsY_expect(J, 'r'); jsY_expect(J, 'u'); jsY_expect(J, 'e');
      return TK_TRUE;

    case EOF:
      return 0; /* EOF */
    }

    if (J->lexchar >= 0x20 && J->lexchar <= 0x7E)
      jsY_error(J, "unexpected character: '%c'", J->lexchar);
    jsY_error(J, "unexpected character: \\u%04X", J->lexchar);
  }
}

Coverage Report

Created: 2026-02-14 06:44