1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/libraries/json/json.c	Fri Jul 25 22:25:53 2014 +0200
     1.3 @@ -0,0 +1,209 @@
     1.4 +#include <lua.h>
     1.5 +#include <lauxlib.h>
     1.6 +#include <string.h>
     1.7 +
     1.8 +#define JSON_VALUE 0
     1.9 +#define JSON_OBJECT_KEY 1
    1.10 +#define JSON_OBJECT_KEY_TERMINATOR 2
    1.11 +#define JSON_OBJECT_VALUE 3
    1.12 +#define JSON_OBJECT_SEPARATOR 4
    1.13 +#define JSON_ARRAY_VALUE 5
    1.14 +#define JSON_ARRAY_SEPARATOR 6
    1.15 +#define JSON_END 7
    1.16 +
    1.17 +static int json_import(lua_State *L) {
    1.18 +  const char *str;
    1.19 +  size_t total;
    1.20 +  size_t pos = 0;
    1.21 +  size_t level = 0;
    1.22 +  int mode = JSON_VALUE;
    1.23 +  char c;
    1.24 +  luaL_Buffer luabuf;
    1.25 +  char *cbuf;
    1.26 +  size_t writepos;
    1.27 +  int aryidx;
    1.28 +  lua_settop(L, 1);
    1.29 +  str = lua_tostring(L, 1);
    1.30 +  total = strlen(str);
    1.31 +json_import_loop:
    1.32 +  while (c = str[pos], c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == '\f') pos++;
    1.33 +  switch (c) {
    1.34 +  case 0:
    1.35 +    if (mode == JSON_END) return 1;
    1.36 +    json_import_unexpected_eof:
    1.37 +    lua_pushnil(L);
    1.38 +    if (level == 0) lua_pushliteral(L, "Empty string");
    1.39 +    else lua_pushliteral(L, "Unexpected end of JSON document");
    1.40 +    return 2;
    1.41 +  case '{':
    1.42 +    if (mode != JSON_VALUE && mode != JSON_OBJECT_VALUE && mode != JSON_ARRAY_VALUE)
    1.43 +      goto json_import_syntax_error;
    1.44 +    pos++;
    1.45 +    lua_newtable(L);
    1.46 +    mode = JSON_OBJECT_KEY;
    1.47 +    level++;
    1.48 +    goto json_import_loop;
    1.49 +  case '[':
    1.50 +    if (mode != JSON_VALUE && mode != JSON_OBJECT_VALUE && mode != JSON_ARRAY_VALUE)
    1.51 +      goto json_import_syntax_error;
    1.52 +    pos++;
    1.53 +    lua_newtable(L);
    1.54 +    lua_pushinteger(L, 0);  // length of array (since it may contain nil's)
    1.55 +    mode = JSON_ARRAY_VALUE;
    1.56 +    level++;
    1.57 +    goto json_import_loop;
    1.58 +  case '}':
    1.59 +    if (mode != JSON_OBJECT_KEY && mode != JSON_OBJECT_SEPARATOR)
    1.60 +      goto json_import_syntax_error;
    1.61 +    goto json_import_close;
    1.62 +  case ']':
    1.63 +    if (mode != JSON_ARRAY_VALUE && mode != JSON_ARRAY_SEPARATOR)
    1.64 +      goto json_import_syntax_error;
    1.65 +    lua_pushvalue(L, -2);  // use array table as key
    1.66 +    lua_insert(L, -2);  // use length of array as value
    1.67 +    lua_rawset(L, lua_upvalueindex(1));  // store length in ephemeron table
    1.68 +    // leaves array table on top of stack
    1.69 +  json_import_close:
    1.70 +    pos++;
    1.71 +    if (--level) {
    1.72 +      if (lua_type(L, -2) == LUA_TNUMBER) {
    1.73 +        mode = JSON_ARRAY_VALUE;
    1.74 +      } else {
    1.75 +        mode = JSON_OBJECT_VALUE;
    1.76 +      }
    1.77 +      goto json_import_process_value;
    1.78 +    } else {
    1.79 +      mode = JSON_END;
    1.80 +    }
    1.81 +    goto json_import_loop;
    1.82 +  case ':':
    1.83 +    if (mode != JSON_OBJECT_KEY_TERMINATOR)
    1.84 +      goto json_import_syntax_error;
    1.85 +    pos++;
    1.86 +    mode = JSON_OBJECT_VALUE;
    1.87 +    goto json_import_loop;
    1.88 +  case ',':
    1.89 +    if (mode == JSON_OBJECT_SEPARATOR) {
    1.90 +      mode = JSON_OBJECT_KEY;
    1.91 +    } else if (mode == JSON_ARRAY_SEPARATOR) {
    1.92 +      mode = JSON_ARRAY_VALUE;
    1.93 +    } else {
    1.94 +      goto json_import_syntax_error;
    1.95 +    }
    1.96 +    pos++;
    1.97 +    goto json_import_loop;
    1.98 +  case '"':
    1.99 +    cbuf = luaL_buffinitsize(L, &luabuf, total-pos);
   1.100 +    writepos = 0;
   1.101 +    pos++;
   1.102 +    while ((c = str[pos++]) != '"') {
   1.103 +      if (c == 0) {
   1.104 +        goto json_import_unexpected_eof;
   1.105 +      } else if (c < 32 || c == 127) {
   1.106 +        lua_pushnil(L);
   1.107 +        lua_pushliteral(L, "Unexpected control character in JSON string");
   1.108 +        return 2;
   1.109 +      } else if (c == '\\') {
   1.110 +        c = str[pos++];
   1.111 +        switch (c) {
   1.112 +        case 0:
   1.113 +          goto json_import_unexpected_eof;
   1.114 +        case '"':
   1.115 +        case '/':
   1.116 +        case '\\':
   1.117 +          cbuf[writepos++] = c;
   1.118 +          break;
   1.119 +        case 'b':
   1.120 +          cbuf[writepos++] = '\b';
   1.121 +          break;
   1.122 +        case 'f':
   1.123 +          cbuf[writepos++] = '\f';
   1.124 +          break;
   1.125 +        case 'n':
   1.126 +          cbuf[writepos++] = '\n';
   1.127 +          break;
   1.128 +        case 'r':
   1.129 +          cbuf[writepos++] = '\r';
   1.130 +          break;
   1.131 +        case 't':
   1.132 +          cbuf[writepos++] = '\t';
   1.133 +          break;
   1.134 +        case 'u':
   1.135 +          lua_pushnil(L);
   1.136 +          lua_pushliteral(L, "JSON unicode escape sequences are not implemented yet");  // TODO
   1.137 +          return 2;
   1.138 +        default:
   1.139 +          lua_pushnil(L);
   1.140 +          lua_pushliteral(L, "Unexpected string escape sequence in JSON document");
   1.141 +          return 2;
   1.142 +        }
   1.143 +      } else {
   1.144 +        cbuf[writepos++] = c;
   1.145 +      }
   1.146 +    }
   1.147 +    if (!c) goto json_import_unexpected_eof;
   1.148 +    luaL_pushresultsize(&luabuf, writepos);
   1.149 +    goto json_import_process_value;
   1.150 +  }
   1.151 +  if (!strncmp(str+pos, "true", 4)) {
   1.152 +    lua_pushboolean(L, 1);
   1.153 +    pos += 4;
   1.154 +  } else if (!strncmp(str+pos, "false", 5)) {
   1.155 +    lua_pushboolean(L, 0);
   1.156 +    pos += 5;
   1.157 +  } else if (!strncmp(str+pos, "null", 4)) {
   1.158 +    lua_pushnil(L);
   1.159 +    pos += 4;
   1.160 +  } else {
   1.161 +    goto json_import_syntax_error;
   1.162 +  }
   1.163 +json_import_process_value:
   1.164 +  switch (mode) {
   1.165 +  case JSON_OBJECT_KEY:
   1.166 +    if (lua_type(L, -1) != LUA_TSTRING) goto json_import_syntax_error;
   1.167 +    mode = JSON_OBJECT_KEY_TERMINATOR;
   1.168 +    goto json_import_loop;
   1.169 +  case JSON_OBJECT_VALUE:
   1.170 +    lua_rawset(L, -3);
   1.171 +    mode = JSON_OBJECT_SEPARATOR;
   1.172 +    goto json_import_loop;
   1.173 +  case JSON_ARRAY_VALUE:
   1.174 +    aryidx = lua_tointeger(L, -2) + 1;
   1.175 +    lua_rawseti(L, -3, aryidx);
   1.176 +    lua_pop(L, 1);
   1.177 +    lua_pushinteger(L, aryidx);
   1.178 +    mode = JSON_ARRAY_SEPARATOR;
   1.179 +    goto json_import_loop;
   1.180 +  case JSON_VALUE:
   1.181 +    mode = JSON_END;
   1.182 +    goto json_import_loop;
   1.183 +  }
   1.184 +json_import_syntax_error:
   1.185 +  lua_pushnil(L);
   1.186 +  lua_pushliteral(L, "Syntax error in JSON document");
   1.187 +  return 2;
   1.188 +}
   1.189 +
   1.190 +static int json_arylen(lua_State *L) {
   1.191 +  lua_settop(L, 1);
   1.192 +  lua_rawget(L, lua_upvalueindex(1));
   1.193 +  return 1;
   1.194 +}
   1.195 +
   1.196 +static const struct luaL_Reg json_module_functions[] = {
   1.197 +  {"import", json_import},
   1.198 +  {"arylen", json_arylen},
   1.199 +  {NULL, NULL}
   1.200 +};
   1.201 +
   1.202 +int luaopen_json(lua_State *L) {
   1.203 +  lua_newtable(L);  // library table
   1.204 +  lua_newtable(L);  // ephemeron table to store the length of arrays (that may contain nil's)
   1.205 +  lua_newtable(L);  // meta table for ephemeron table
   1.206 +  lua_pushliteral(L, "__mode");
   1.207 +  lua_pushliteral(L, "k");
   1.208 +  lua_rawset(L, -3);
   1.209 +  lua_setmetatable(L, -2);
   1.210 +  luaL_setfuncs(L, json_module_functions, 1);
   1.211 +  return 1;
   1.212 +}