rev |
line source |
jbe@121
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1 #include <lua.h>
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jbe@121
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2 #include <lauxlib.h>
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jbe@122
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3 #include <stdlib.h>
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jbe@121
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4 #include <string.h>
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jbe@154
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5 #include <math.h>
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jbe@121
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6
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jbe@144
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7 // maximum number of nested JSON values (objects and arrays):
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jbe@182
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8 // NOTE: json_import can store 2^32 / 3 levels on stack swap (using
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jbe@183
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9 // also negative indicies after integer wraparound), and
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jbe@183
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10 // json_export can store even more levels, so 1024^3 =
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jbe@183
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11 // 1073741824 is a safe value and allows practically unlimited
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jbe@183
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12 // levels for JSON documents <= 2 GiB.
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jbe@182
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13 #define JSON_MAXDEPTH (1024*1024*1024)
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jbe@142
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14
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jbe@193
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15 // define type JSON_LIGHTUSERDATA and
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jbe@193
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16 // generate dummy memory addresses for lightuserdata values:
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jbe@193
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17 #define JSON_LIGHTUSERDATA char
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jbe@193
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18 static struct {
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jbe@193
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19 JSON_LIGHTUSERDATA nullmark; // lightuserdata value represents a NULL value
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jbe@193
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20 JSON_LIGHTUSERDATA shadowtbl; // lightuserdata key for shadow table
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jbe@193
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21 } json_lightuserdata;
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jbe@193
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22
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jbe@193
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23 // macros for special nullmark value:
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jbe@193
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24 #define json_isnullmark(L, i) (lua_touserdata((L), (i)) == &json_lightuserdata.nullmark)
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jbe@193
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25 #define json_pushnullmark(L) lua_pushlightuserdata((L), &json_lightuserdata.nullmark)
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jbe@193
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26
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jbe@193
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27 // macros for getting and setting shadow tables
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jbe@193
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28 #define json_setshadow(L, i) lua_rawsetp((L), (i), &json_lightuserdata.shadowtbl)
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jbe@193
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29 #define json_getshadow(L, i) lua_rawgetp((L), (i), &json_lightuserdata.shadowtbl)
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jbe@193
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30 #define json_createproxy(L) lua_createtable((L), 0, 1)
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jbe@193
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31
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jbe@193
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32 // generate additional dummy memory addresses that represent Lua objects
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jbe@193
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33 // via lightuserdata keys and LUA_REGISTRYINDEX:
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jbe@193
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34 static struct {
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jbe@193
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35 JSON_LIGHTUSERDATA objectmt; // metatable for JSON objects
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jbe@193
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36 JSON_LIGHTUSERDATA arraymt; // metatable for JSON arrays
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jbe@193
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37 } json_registry;
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jbe@155
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38
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jbe@144
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39 // macros for usage of Lua registry:
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jbe@145
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40 #define json_regpointer(x) (&json_registry.x)
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jbe@151
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41 #define json_regfetchpointer(L, x) lua_rawgetp((L), LUA_REGISTRYINDEX, (x))
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jbe@151
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42 #define json_regfetch(L, x) json_regfetchpointer(L, json_regpointer(x))
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jbe@151
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43 #define json_regstore(L, x) lua_rawsetp(L, LUA_REGISTRYINDEX, json_regpointer(x))
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jbe@145
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44
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jbe@157
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45 // returns the string "<JSON null marker>":
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jbe@157
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46 static int json_nullmark_tostring(lua_State *L) {
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jbe@157
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47 lua_pushliteral(L, "<JSON null marker>");
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jbe@157
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48 return 1;
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jbe@157
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49 }
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jbe@157
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50
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jbe@202
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51 #define json_object_source_idx 1
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jbe@202
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52 #define json_object_iterator_idx 2
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jbe@202
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53 #define json_object_output_idx 3
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jbe@202
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54 #define json_object_shadow_idx 4
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jbe@202
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55 #define json_object_iterfun_idx 5
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jbe@202
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56 #define json_object_itertbl_idx 6
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jbe@169
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57
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jbe@202
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58 // converts a Lua table (or any other iterable value) to a JSON object:
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jbe@169
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59 // (does never modify the argument, returns an empty object or array if argument is nil)
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jbe@202
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60 static int json_object(lua_State *L) {
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jbe@171
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61 // determine is argument is given:
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jbe@202
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62 if (lua_isnoneornil(L, json_object_source_idx)) {
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jbe@171
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63 // if no argument is given (or if argument is nil),
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jbe@193
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64 // create proxy table with shadow table, and leave proxy table on top of stack:
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jbe@193
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65 json_createproxy(L);
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jbe@169
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66 lua_newtable(L);
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jbe@193
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67 json_setshadow(L, -2);
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jbe@169
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68 } else {
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jbe@171
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69 // if an argument was given,
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jbe@193
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70 // stack shall contain only one function argument:
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jbe@171
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71 lua_settop(L, 1);
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jbe@193
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72 // check if there is an iterator function in its metatable:
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jbe@202
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73 if (luaL_getmetafield(L, json_object_source_idx, "__pairs")) {
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jbe@193
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74 // if there is an iterator function,
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jbe@193
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75 // leave it on stack position 2 and verify its type:
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jbe@202
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76 if (lua_type(L, json_object_iterator_idx) != LUA_TFUNCTION)
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jbe@202
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77 return luaL_error(L, "__pairs metamethod is not a function");
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jbe@169
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78 } else {
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jbe@193
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79 // if there is no iterator function,
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jbe@193
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80 // verify the type of the argument itself:
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jbe@202
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81 luaL_checktype(L, json_object_source_idx, LUA_TTABLE);
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jbe@193
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82 // push nil onto stack position 2:
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jbe@169
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83 lua_pushnil(L);
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jbe@143
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84 }
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jbe@171
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85 // create result table on stack position 3:
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jbe@193
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86 json_createproxy(L);
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jbe@169
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87 // create shadow table on stack position 4:
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jbe@169
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88 lua_newtable(L);
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jbe@193
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89 lua_pushvalue(L, -1);
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jbe@193
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90 json_setshadow(L, -3);
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jbe@171
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91 // check if iterator function exists:
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jbe@202
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92 if (lua_isnil(L, json_object_iterator_idx)) {
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jbe@171
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93 // if there is no iterator function,
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jbe@202
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94 // copy all string key value pairs to shadow table:
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jbe@202
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95 for (lua_pushnil(L); lua_next(L, json_object_source_idx); lua_pop(L, 1)) {
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jbe@202
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96 if (lua_type(L, -2) == LUA_TSTRING) {
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jbe@202
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97 lua_pushvalue(L, -2);
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jbe@202
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98 lua_pushvalue(L, -2);
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jbe@202
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99 lua_rawset(L, json_object_shadow_idx);
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jbe@171
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100 }
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jbe@169
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101 }
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jbe@169
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102 } else {
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jbe@172
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103 // if there is an iterator function,
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jbe@172
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104 // call iterator function with source value (first argument)
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jbe@172
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105 // and store 3 result values on stack positions 5 through 7:
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jbe@202
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106 lua_pushvalue(L, json_object_iterator_idx);
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jbe@172
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107 lua_pushvalue(L, 1);
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jbe@172
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108 lua_call(L, 1, 3);
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jbe@175
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109 // iterate through key value pairs and store some of them in shadow table
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jbe@174
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110 // while replacing nil values with null-marker:
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jbe@172
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111 while (1) {
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jbe@175
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112 // call iterfun function:
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jbe@202
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113 lua_pushvalue(L, json_object_iterfun_idx);
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jbe@202
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114 lua_pushvalue(L, json_object_itertbl_idx);
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jbe@172
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115 lua_pushvalue(L, -3);
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jbe@172
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116 lua_remove(L, -4);
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jbe@172
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117 lua_call(L, 2, 2);
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jbe@175
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118 // break iteration loop if key is nil:
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jbe@172
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119 if (lua_isnil(L, -2)) break;
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jbe@175
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120 // store key value pair only if key type is correct:
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jbe@202
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121 if (lua_type(L, -2) == LUA_TSTRING) {
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jbe@175
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122 // if key type is correct,
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jbe@175
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123 // push key onto stack:
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jbe@172
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124 lua_pushvalue(L, -2);
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jbe@175
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125 // if value is nil, push null-marker onto stack (as value):
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jbe@174
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126 if (lua_isnil(L, -2)) json_pushnullmark(L);
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jbe@175
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127 // else push value onto stack:
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jbe@174
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128 else lua_pushvalue(L, -2);
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jbe@175
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129 // set key value pair in shadow table:
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jbe@202
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130 lua_rawset(L, json_object_shadow_idx);
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jbe@172
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131 }
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jbe@175
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132 // pop value from stack, but leave key on stack:
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jbe@172
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133 lua_pop(L, 1);
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jbe@172
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134 }
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jbe@143
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135 }
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jbe@171
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136 // let result table be on top of stack:
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jbe@202
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137 lua_settop(L, json_object_output_idx);
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jbe@136
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138 }
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jbe@171
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139 // set metatable (for result table on top of stack):
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jbe@202
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140 json_regfetch(L, objectmt);
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jbe@169
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141 lua_setmetatable(L, -2);
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jbe@171
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142 // return table on top of stack:
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jbe@136
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143 return 1;
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jbe@136
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144 }
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jbe@136
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145
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jbe@202
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146 #define json_array_source_idx 1
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jbe@202
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147 #define json_array_output_idx 2
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jbe@202
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148 #define json_array_shadow_idx 3
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jbe@136
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149
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jbe@175
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150 // converts a Lua table (or any other iterable value) to a JSON array:
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jbe@175
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151 // (does never modify the argument, returns an empty object or array if argument is nil)
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jbe@136
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152 static int json_array(lua_State *L) {
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jbe@202
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153 // determine is argument is given:
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jbe@202
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154 if (lua_isnoneornil(L, json_array_source_idx)) {
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jbe@202
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155 // if no argument is given (or if argument is nil),
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jbe@202
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156 // create proxy table with shadow table, and leave proxy table on top of stack:
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jbe@202
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157 json_createproxy(L);
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jbe@202
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158 lua_newtable(L);
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jbe@202
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159 json_setshadow(L, -2);
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jbe@202
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160 } else {
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jbe@202
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161 lua_Integer arrayidx, arraylen;
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jbe@202
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162 // if an argument was given,
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jbe@202
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163 // stack shall contain only one function argument:
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jbe@202
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164 lua_settop(L, 1);
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jbe@202
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165 // create result table on stack position 2:
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jbe@202
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166 json_createproxy(L);
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jbe@202
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167 // create shadow table on stack position 3:
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jbe@202
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168 lua_newtable(L);
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jbe@202
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169 lua_pushvalue(L, -1);
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jbe@202
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170 json_setshadow(L, -3);
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jbe@202
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171 // determine length of array:
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jbe@202
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172 arraylen = luaL_len(L, json_array_source_idx);
|
jbe@202
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173 // for an array, copy consecutive integer value pairs to shadow table:
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jbe@202
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174 for (arrayidx=0; arrayidx<arraylen; ) {
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jbe@202
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175 // increment arrayidx at head of loop:
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jbe@202
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176 arrayidx++;
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jbe@202
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177 // get next array entry:
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jbe@202
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178 lua_pushinteger(L, arrayidx);
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jbe@202
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179 lua_gettable(L, json_array_source_idx);
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jbe@202
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180 // check if value is nil:
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jbe@202
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181 if (lua_isnil(L, -1)) {
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jbe@202
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182 // if yes, replace it with null-marker:
|
jbe@202
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183 lua_pop(L, 1);
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jbe@202
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184 json_pushnullmark(L);
|
jbe@202
|
185 }
|
jbe@202
|
186 // store value in shadow table:
|
jbe@202
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187 lua_rawseti(L, json_array_shadow_idx, arrayidx);
|
jbe@202
|
188 }
|
jbe@202
|
189 // let result table be on top of stack:
|
jbe@202
|
190 lua_settop(L, json_array_output_idx);
|
jbe@202
|
191 }
|
jbe@202
|
192 // set metatable (for result table on top of stack):
|
jbe@202
|
193 json_regfetch(L, arraymt);
|
jbe@202
|
194 lua_setmetatable(L, -2);
|
jbe@202
|
195 // return table on top of stack:
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jbe@202
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196 return 1;
|
jbe@136
|
197 }
|
jbe@136
|
198
|
jbe@145
|
199 // internal states of JSON parser:
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jbe@124
|
200 #define JSON_STATE_VALUE 0
|
jbe@124
|
201 #define JSON_STATE_OBJECT_KEY 1
|
jbe@124
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202 #define JSON_STATE_OBJECT_KEY_TERMINATOR 2
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jbe@124
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203 #define JSON_STATE_OBJECT_VALUE 3
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jbe@124
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204 #define JSON_STATE_OBJECT_SEPARATOR 4
|
jbe@124
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205 #define JSON_STATE_ARRAY_VALUE 5
|
jbe@124
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206 #define JSON_STATE_ARRAY_SEPARATOR 6
|
jbe@124
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207 #define JSON_STATE_END 7
|
jbe@121
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208
|
jbe@145
|
209 // special Lua stack indicies for json_import function:
|
jbe@138
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210 #define json_import_objectmt_idx 2
|
jbe@138
|
211 #define json_import_arraymt_idx 3
|
jbe@193
|
212 #define json_import_stackswap_idx 4
|
jbe@138
|
213
|
jbe@168
|
214 // macros for hex decoding:
|
jbe@168
|
215 #define json_utf16_surrogate(x) ((x) >= 0xD800 && (x) <= 0xDFFF)
|
jbe@168
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216 #define json_utf16_lead(x) ((x) >= 0xD800 && (x) <= 0xDBFF)
|
jbe@168
|
217 #define json_utf16_tail(x) ((x) >= 0xDC00 && (x) <= 0xDFFF)
|
jbe@167
|
218 #define json_import_readhex(x) \
|
jbe@167
|
219 do { \
|
jbe@167
|
220 x = 0; \
|
jbe@167
|
221 for (i=0; i<4; i++) { \
|
jbe@167
|
222 x <<= 4; \
|
jbe@167
|
223 c = str[pos++]; \
|
jbe@167
|
224 if (c >= '0' && c <= '9') x += c - '0'; \
|
jbe@167
|
225 else if (c >= 'A' && c <= 'F') x += c - 'A' + 10; \
|
jbe@167
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226 else if (c >= 'a' && c <= 'f') x += c - 'a' + 10; \
|
jbe@167
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227 else if (c == 0) goto json_import_unexpected_eof; \
|
jbe@167
|
228 else goto json_import_unexpected_escape; \
|
jbe@167
|
229 } \
|
jbe@167
|
230 } while (0)
|
jbe@167
|
231
|
jbe@136
|
232 // decodes a JSON document:
|
jbe@121
|
233 static int json_import(lua_State *L) {
|
jbe@181
|
234 int stackswapidx = 0; // elements in stack swap table
|
jbe@181
|
235 int i; // loop variable
|
jbe@181
|
236 const char *str; // string to parse
|
jbe@181
|
237 size_t total; // total length of string to parse
|
jbe@181
|
238 size_t pos = 0; // current position in string to parse
|
jbe@181
|
239 size_t level = 0; // nested levels of objects/arrays currently being processed
|
jbe@145
|
240 int mode = JSON_STATE_VALUE; // state of parser (i.e. "what's expected next?")
|
jbe@181
|
241 unsigned char c; // variable to store a single character to be processed (unsigned!)
|
jbe@181
|
242 luaL_Buffer luabuf; // Lua buffer to decode JSON string values
|
jbe@181
|
243 char *cbuf; // C buffer to decode JSON string values
|
jbe@181
|
244 size_t outlen; // maximum length or write position of C buffer
|
jbe@181
|
245 long codepoint; // decoded UTF-16 character or higher codepoint
|
jbe@181
|
246 long utf16tail; // second decoded UTF-16 character (surrogate tail)
|
jbe@181
|
247 size_t arraylen; // variable to temporarily store the array length
|
jbe@166
|
248 // require string as argument and convert to C string with length information:
|
jbe@166
|
249 str = luaL_checklstring(L, 1, &total);
|
jbe@166
|
250 // if string contains a NULL byte, this is a syntax error
|
jbe@166
|
251 if (strlen(str) != total) goto json_import_syntax_error;
|
jbe@147
|
252 // stack shall contain one function argument:
|
jbe@138
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253 lua_settop(L, 1);
|
jbe@147
|
254 // push objectmt onto stack position 2:
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jbe@144
|
255 json_regfetch(L, objectmt);
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jbe@147
|
256 // push arraymt onto stack position 3:
|
jbe@144
|
257 json_regfetch(L, arraymt);
|
jbe@181
|
258 // push table for stack swapping onto stack position 5:
|
jbe@181
|
259 // (needed to avoid Lua stack overflows)
|
jbe@181
|
260 lua_newtable(L);
|
jbe@136
|
261 // main loop of parser:
|
jbe@136
|
262 json_import_loop:
|
jbe@136
|
263 // skip whitespace and store next character in variable 'c':
|
jbe@146
|
264 while (c = str[pos],
|
jbe@146
|
265 c == ' ' ||
|
jbe@146
|
266 c == '\f' ||
|
jbe@146
|
267 c == '\n' ||
|
jbe@146
|
268 c == '\r' ||
|
jbe@146
|
269 c == '\t' ||
|
jbe@146
|
270 c == '\v'
|
jbe@146
|
271 ) pos++;
|
jbe@170
|
272 // NOTE: variable c needs to be unsigned in the following code
|
jbe@136
|
273 // switch statement to handle certain (single) characters:
|
jbe@121
|
274 switch (c) {
|
jbe@136
|
275 // handle end of JSON document:
|
jbe@121
|
276 case 0:
|
jbe@136
|
277 // if end of JSON document was expected, then return top element of stack as result:
|
jbe@124
|
278 if (mode == JSON_STATE_END) return 1;
|
jbe@136
|
279 // otherwise, the JSON document was malformed:
|
jbe@167
|
280 if (level == 0) {
|
jbe@167
|
281 lua_pushnil(L);
|
jbe@167
|
282 lua_pushliteral(L, "Empty string");
|
jbe@167
|
283 } else {
|
jbe@167
|
284 json_import_unexpected_eof:
|
jbe@167
|
285 lua_pushnil(L);
|
jbe@167
|
286 lua_pushliteral(L, "Unexpected end of JSON document");
|
jbe@167
|
287 }
|
jbe@121
|
288 return 2;
|
jbe@181
|
289 // new JSON object or JSON array:
|
jbe@121
|
290 case '{':
|
jbe@181
|
291 case '[':
|
jbe@181
|
292 // if an encountered JSON object is not expected here, then return an error:
|
jbe@146
|
293 if (
|
jbe@181
|
294 c == '{' &&
|
jbe@181
|
295 mode != JSON_STATE_VALUE &&
|
jbe@181
|
296 mode != JSON_STATE_OBJECT_VALUE &&
|
jbe@181
|
297 mode != JSON_STATE_ARRAY_VALUE
|
jbe@181
|
298 ) goto json_import_syntax_error;
|
jbe@181
|
299 // if an encountered JSON array is not expected here, then return an error:
|
jbe@181
|
300 if (
|
jbe@181
|
301 c == '[' &&
|
jbe@146
|
302 mode != JSON_STATE_VALUE &&
|
jbe@146
|
303 mode != JSON_STATE_OBJECT_VALUE &&
|
jbe@146
|
304 mode != JSON_STATE_ARRAY_VALUE
|
jbe@146
|
305 ) goto json_import_syntax_error;
|
jbe@181
|
306 // consume input character:
|
jbe@181
|
307 pos++;
|
jbe@181
|
308 // limit nested levels:
|
jbe@181
|
309 if (level >= JSON_MAXDEPTH) {
|
jbe@181
|
310 lua_pushnil(L);
|
jbe@181
|
311 lua_pushfstring(L, "More than %d nested JSON levels", JSON_MAXDEPTH);
|
jbe@181
|
312 return 2;
|
jbe@181
|
313 }
|
jbe@181
|
314 // swap Lua stack entries for previous level to swap table:
|
jbe@181
|
315 // (avoids depth limitations due to Lua stack size)
|
jbe@181
|
316 if (level) {
|
jbe@181
|
317 lua_rawseti(L, json_import_stackswap_idx, ++stackswapidx);
|
jbe@181
|
318 lua_rawseti(L, json_import_stackswap_idx, ++stackswapidx);
|
jbe@181
|
319 lua_rawseti(L, json_import_stackswap_idx, ++stackswapidx);
|
jbe@181
|
320 }
|
jbe@181
|
321 // increment level:
|
jbe@181
|
322 level++;
|
jbe@181
|
323 // create JSON object or JSON array on stack:
|
jbe@136
|
324 lua_newtable(L);
|
jbe@181
|
325 // set metatable of JSON object or JSON array:
|
jbe@181
|
326 lua_pushvalue(L, c == '{' ? json_import_objectmt_idx : json_import_arraymt_idx);
|
jbe@125
|
327 lua_setmetatable(L, -2);
|
jbe@136
|
328 // create internal shadow table on stack:
|
jbe@136
|
329 lua_newtable(L);
|
jbe@146
|
330 // register internal shadow table:
|
jbe@193
|
331 lua_pushvalue(L, -1);
|
jbe@193
|
332 json_setshadow(L, -3);
|
jbe@181
|
333 // distinguish between JSON objects and JSON arrays:
|
jbe@181
|
334 if (c == '{') {
|
jbe@181
|
335 // if JSON object,
|
jbe@181
|
336 // expect object key (or end of object) to follow:
|
jbe@181
|
337 mode = JSON_STATE_OBJECT_KEY;
|
jbe@181
|
338 } else {
|
jbe@181
|
339 // if JSON array,
|
jbe@181
|
340 // expect array value (or end of array) to follow:
|
jbe@181
|
341 mode = JSON_STATE_ARRAY_VALUE;
|
jbe@181
|
342 // add nil as key (needed to keep stack balance) and as magic to detect arrays:
|
jbe@181
|
343 if (c == '[') lua_pushnil(L);
|
jbe@142
|
344 }
|
jbe@121
|
345 goto json_import_loop;
|
jbe@136
|
346 // end of JSON object:
|
jbe@121
|
347 case '}':
|
jbe@136
|
348 // if end of JSON object is not expected here, then return an error:
|
jbe@146
|
349 if (
|
jbe@146
|
350 mode != JSON_STATE_OBJECT_KEY &&
|
jbe@146
|
351 mode != JSON_STATE_OBJECT_SEPARATOR
|
jbe@146
|
352 ) goto json_import_syntax_error;
|
jbe@136
|
353 // jump to common code for end of JSON object and JSON array:
|
jbe@121
|
354 goto json_import_close;
|
jbe@136
|
355 // end of JSON array:
|
jbe@121
|
356 case ']':
|
jbe@136
|
357 // if end of JSON array is not expected here, then return an error:
|
jbe@146
|
358 if (
|
jbe@146
|
359 mode != JSON_STATE_ARRAY_VALUE &&
|
jbe@146
|
360 mode != JSON_STATE_ARRAY_SEPARATOR
|
jbe@146
|
361 ) goto json_import_syntax_error;
|
jbe@146
|
362 // pop nil key/magic (that was needed to keep stack balance):
|
jbe@140
|
363 lua_pop(L, 1);
|
jbe@136
|
364 // continue with common code for end of JSON object and JSON array:
|
jbe@136
|
365 // common code for end of JSON object or JSON array:
|
jbe@121
|
366 json_import_close:
|
jbe@136
|
367 // consume input character:
|
jbe@121
|
368 pos++;
|
jbe@136
|
369 // pop shadow table:
|
jbe@136
|
370 lua_pop(L, 1);
|
jbe@136
|
371 // check if nested:
|
jbe@121
|
372 if (--level) {
|
jbe@146
|
373 // if nested,
|
jbe@181
|
374 // restore previous stack elements from stack swap:
|
jbe@181
|
375 lua_rawgeti(L, json_import_stackswap_idx, stackswapidx--);
|
jbe@181
|
376 lua_insert(L, -2);
|
jbe@181
|
377 lua_rawgeti(L, json_import_stackswap_idx, stackswapidx--);
|
jbe@181
|
378 lua_insert(L, -2);
|
jbe@181
|
379 lua_rawgeti(L, json_import_stackswap_idx, stackswapidx--);
|
jbe@181
|
380 lua_insert(L, -2);
|
jbe@146
|
381 // check if outer(!) structure is an array or object:
|
jbe@140
|
382 if (lua_isnil(L, -2)) {
|
jbe@136
|
383 // select array value processing:
|
jbe@124
|
384 mode = JSON_STATE_ARRAY_VALUE;
|
jbe@121
|
385 } else {
|
jbe@136
|
386 // select object value processing:
|
jbe@124
|
387 mode = JSON_STATE_OBJECT_VALUE;
|
jbe@121
|
388 }
|
jbe@136
|
389 // store value in outer structure:
|
jbe@121
|
390 goto json_import_process_value;
|
jbe@121
|
391 }
|
jbe@136
|
392 // if not nested, then expect end of JSON document and continue with loop:
|
jbe@136
|
393 mode = JSON_STATE_END;
|
jbe@121
|
394 goto json_import_loop;
|
jbe@136
|
395 // key terminator:
|
jbe@121
|
396 case ':':
|
jbe@136
|
397 // if key terminator is not expected here, then return an error:
|
jbe@124
|
398 if (mode != JSON_STATE_OBJECT_KEY_TERMINATOR)
|
jbe@121
|
399 goto json_import_syntax_error;
|
jbe@136
|
400 // consume input character:
|
jbe@121
|
401 pos++;
|
jbe@146
|
402 // expect object value to follow:
|
jbe@124
|
403 mode = JSON_STATE_OBJECT_VALUE;
|
jbe@146
|
404 // continue with loop:
|
jbe@121
|
405 goto json_import_loop;
|
jbe@136
|
406 // value terminator (NOTE: trailing comma at end of value or key-value list is tolerated by this parser)
|
jbe@121
|
407 case ',':
|
jbe@146
|
408 // branch according to parser state:
|
jbe@124
|
409 if (mode == JSON_STATE_OBJECT_SEPARATOR) {
|
jbe@146
|
410 // expect an object key to follow:
|
jbe@124
|
411 mode = JSON_STATE_OBJECT_KEY;
|
jbe@124
|
412 } else if (mode == JSON_STATE_ARRAY_SEPARATOR) {
|
jbe@146
|
413 // expect an array value to follow:
|
jbe@124
|
414 mode = JSON_STATE_ARRAY_VALUE;
|
jbe@121
|
415 } else {
|
jbe@136
|
416 // if value terminator is not expected here, then return an error:
|
jbe@136
|
417 goto json_import_syntax_error;
|
jbe@121
|
418 }
|
jbe@136
|
419 // consume input character:
|
jbe@121
|
420 pos++;
|
jbe@136
|
421 // continue with loop:
|
jbe@121
|
422 goto json_import_loop;
|
jbe@136
|
423 // string literal:
|
jbe@121
|
424 case '"':
|
jbe@146
|
425 // consume quote character:
|
jbe@146
|
426 pos++;
|
jbe@162
|
427 // find last character in input string:
|
jbe@162
|
428 outlen = pos;
|
jbe@162
|
429 while ((c = str[outlen]) != '"') {
|
jbe@161
|
430 // consume one character:
|
jbe@162
|
431 outlen++;
|
jbe@161
|
432 // handle unexpected end of JSON document:
|
jbe@161
|
433 if (c == 0) goto json_import_unexpected_eof;
|
jbe@161
|
434 // consume one extra character when encountering an escaped quote:
|
jbe@162
|
435 else if (c == '\\' && str[outlen] == '"') outlen++;
|
jbe@161
|
436 }
|
jbe@162
|
437 // determine buffer length:
|
jbe@162
|
438 outlen -= pos;
|
jbe@161
|
439 // check if string is non empty:
|
jbe@162
|
440 if (outlen) {
|
jbe@161
|
441 // prepare buffer to decode string (with maximum possible length) and set write position to zero:
|
jbe@162
|
442 cbuf = luaL_buffinitsize(L, &luabuf, outlen);
|
jbe@162
|
443 outlen = 0;
|
jbe@161
|
444 // loop through the characters until encountering end quote:
|
jbe@161
|
445 while ((c = str[pos++]) != '"') {
|
jbe@162
|
446 // NOTE: unexpected end cannot happen anymore
|
jbe@162
|
447 if (c < 32 || c == 127) {
|
jbe@161
|
448 // do not allow ASCII control characters:
|
jbe@161
|
449 // NOTE: illegal UTF-8 sequences and extended control characters are not sanitized
|
jbe@161
|
450 // by this parser to allow different encodings than Unicode
|
jbe@161
|
451 lua_pushnil(L);
|
jbe@161
|
452 lua_pushliteral(L, "Unexpected control character in JSON string");
|
jbe@161
|
453 return 2;
|
jbe@161
|
454 } else if (c == '\\') {
|
jbe@161
|
455 // read next char after backslash escape:
|
jbe@161
|
456 c = str[pos++];
|
jbe@161
|
457 switch (c) {
|
jbe@161
|
458 // unexpected end-of-string:
|
jbe@161
|
459 case 0:
|
jbe@161
|
460 goto json_import_unexpected_eof;
|
jbe@161
|
461 // unescaping of quotation mark, slash, and backslash:
|
jbe@161
|
462 case '"':
|
jbe@161
|
463 case '/':
|
jbe@161
|
464 case '\\':
|
jbe@162
|
465 cbuf[outlen++] = c;
|
jbe@161
|
466 break;
|
jbe@161
|
467 // unescaping of backspace:
|
jbe@162
|
468 case 'b': cbuf[outlen++] = '\b'; break;
|
jbe@161
|
469 // unescaping of form-feed:
|
jbe@162
|
470 case 'f': cbuf[outlen++] = '\f'; break;
|
jbe@161
|
471 // unescaping of new-line:
|
jbe@162
|
472 case 'n': cbuf[outlen++] = '\n'; break;
|
jbe@161
|
473 // unescaping of carriage-return:
|
jbe@162
|
474 case 'r': cbuf[outlen++] = '\r'; break;
|
jbe@161
|
475 // unescaping of tabulator:
|
jbe@162
|
476 case 't': cbuf[outlen++] = '\t'; break;
|
jbe@161
|
477 // unescaping of UTF-16 characters
|
jbe@161
|
478 case 'u':
|
jbe@167
|
479 // decode 4 hex nibbles:
|
jbe@167
|
480 json_import_readhex(codepoint);
|
jbe@167
|
481 // handle surrogate character:
|
jbe@167
|
482 if (json_utf16_surrogate(codepoint)) {
|
jbe@167
|
483 // check if first surrogate is in valid range:
|
jbe@167
|
484 if (json_utf16_lead(codepoint)) {
|
jbe@167
|
485 // require second surrogate:
|
jbe@167
|
486 if ((c = str[pos++]) != '\\' || (c = str[pos++]) != 'u') {
|
jbe@167
|
487 if (c == 0) goto json_import_unexpected_eof;
|
jbe@167
|
488 else goto json_import_wrong_surrogate;
|
jbe@167
|
489 }
|
jbe@167
|
490 // read 4 hex nibbles of second surrogate character:
|
jbe@167
|
491 json_import_readhex(utf16tail);
|
jbe@167
|
492 // check if second surrogate is in valid range:
|
jbe@167
|
493 if (!json_utf16_tail(utf16tail)) goto json_import_wrong_surrogate;
|
jbe@167
|
494 // calculate codepoint:
|
jbe@167
|
495 codepoint = 0x10000 + (utf16tail - 0xDC00) + (codepoint - 0xD800) * 0x400;
|
jbe@167
|
496 } else {
|
jbe@167
|
497 // throw error for wrong surrogates:
|
jbe@167
|
498 json_import_wrong_surrogate:
|
jbe@167
|
499 lua_pushnil(L);
|
jbe@167
|
500 lua_pushliteral(L, "Illegal UTF-16 surrogate in JSON string escape sequence");
|
jbe@167
|
501 return 2;
|
jbe@167
|
502 }
|
jbe@167
|
503 }
|
jbe@167
|
504 // encode as UTF-8:
|
jbe@167
|
505 if (codepoint < 0x80) {
|
jbe@167
|
506 cbuf[outlen++] = (char)codepoint;
|
jbe@167
|
507 } else if (codepoint < 0x800) {
|
jbe@167
|
508 cbuf[outlen++] = (char)(0xc0 | (codepoint >> 6));
|
jbe@167
|
509 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
|
jbe@167
|
510 } else if (codepoint < 0x10000) {
|
jbe@167
|
511 cbuf[outlen++] = (char)(0xe0 | (codepoint >> 12));
|
jbe@167
|
512 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 6) & 0x3f));
|
jbe@167
|
513 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
|
jbe@167
|
514 } else {
|
jbe@167
|
515 cbuf[outlen++] = (char)(0xf0 | (codepoint >> 18));
|
jbe@167
|
516 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 12) & 0x3f));
|
jbe@167
|
517 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 6) & 0x3f));
|
jbe@167
|
518 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
|
jbe@167
|
519 }
|
jbe@167
|
520 break;
|
jbe@161
|
521 // unexpected escape sequence:
|
jbe@161
|
522 default:
|
jbe@167
|
523 json_import_unexpected_escape:
|
jbe@161
|
524 lua_pushnil(L);
|
jbe@161
|
525 lua_pushliteral(L, "Unexpected string escape sequence in JSON document");
|
jbe@161
|
526 return 2;
|
jbe@161
|
527 }
|
jbe@161
|
528 } else {
|
jbe@161
|
529 // normal character:
|
jbe@162
|
530 cbuf[outlen++] = c;
|
jbe@121
|
531 }
|
jbe@121
|
532 }
|
jbe@161
|
533 // process buffer to Lua string:
|
jbe@162
|
534 luaL_pushresultsize(&luabuf, outlen);
|
jbe@161
|
535 } else {
|
jbe@161
|
536 // if JSON string is empty,
|
jbe@161
|
537 // push empty Lua string:
|
jbe@161
|
538 lua_pushliteral(L, "");
|
jbe@167
|
539 // consume closing quote:
|
jbe@167
|
540 pos++;
|
jbe@121
|
541 }
|
jbe@136
|
542 // continue with processing of decoded string:
|
jbe@121
|
543 goto json_import_process_value;
|
jbe@121
|
544 }
|
jbe@136
|
545 // process values whose type is is not deducible from a single character:
|
jbe@136
|
546 if ((c >= '0' && c <= '9') || c == '-' || c == '+') {
|
jbe@146
|
547 // for numbers,
|
jbe@146
|
548 // use strtod() call to parse a (double precision) floating point number:
|
jbe@167
|
549 double numval;
|
jbe@122
|
550 char *endptr;
|
jbe@122
|
551 numval = strtod(str+pos, &endptr);
|
jbe@146
|
552 // catch parsing errors:
|
jbe@122
|
553 if (endptr == str+pos) goto json_import_syntax_error;
|
jbe@146
|
554 // consume characters that were parsed:
|
jbe@122
|
555 pos += endptr - (str+pos);
|
jbe@146
|
556 // push parsed (double precision) floating point number on Lua stack:
|
jbe@122
|
557 lua_pushnumber(L, numval);
|
jbe@122
|
558 } else if (!strncmp(str+pos, "true", 4)) {
|
jbe@136
|
559 // consume 4 input characters for "true":
|
jbe@121
|
560 pos += 4;
|
jbe@147
|
561 // put Lua true value onto stack:
|
jbe@136
|
562 lua_pushboolean(L, 1);
|
jbe@121
|
563 } else if (!strncmp(str+pos, "false", 5)) {
|
jbe@136
|
564 // consume 5 input characters for "false":
|
jbe@121
|
565 pos += 5;
|
jbe@147
|
566 // put Lua false value onto stack:
|
jbe@136
|
567 lua_pushboolean(L, 0);
|
jbe@121
|
568 } else if (!strncmp(str+pos, "null", 4)) {
|
jbe@136
|
569 // consume 4 input characters for "null":
|
jbe@136
|
570 pos += 4;
|
jbe@194
|
571 // push special null-marker onto stack:
|
jbe@194
|
572 json_pushnullmark(L);
|
jbe@121
|
573 } else {
|
jbe@136
|
574 // all other cases are a syntax error:
|
jbe@121
|
575 goto json_import_syntax_error;
|
jbe@121
|
576 }
|
jbe@136
|
577 // process a decoded value or key value pair (expected on top of Lua stack):
|
jbe@136
|
578 json_import_process_value:
|
jbe@121
|
579 switch (mode) {
|
jbe@136
|
580 // an object key has been read:
|
jbe@124
|
581 case JSON_STATE_OBJECT_KEY:
|
jbe@136
|
582 // if an object key is not a string, then this is a syntax error:
|
jbe@121
|
583 if (lua_type(L, -1) != LUA_TSTRING) goto json_import_syntax_error;
|
jbe@146
|
584 // expect key terminator to follow:
|
jbe@124
|
585 mode = JSON_STATE_OBJECT_KEY_TERMINATOR;
|
jbe@146
|
586 // continue with loop:
|
jbe@121
|
587 goto json_import_loop;
|
jbe@136
|
588 // a key value pair has been read:
|
jbe@124
|
589 case JSON_STATE_OBJECT_VALUE:
|
jbe@136
|
590 // store key value pair in outer shadow table:
|
jbe@130
|
591 lua_rawset(L, -3);
|
jbe@146
|
592 // expect value terminator (or end of object) to follow:
|
jbe@124
|
593 mode = JSON_STATE_OBJECT_SEPARATOR;
|
jbe@146
|
594 // continue with loop:
|
jbe@121
|
595 goto json_import_loop;
|
jbe@136
|
596 // an array value has been read:
|
jbe@124
|
597 case JSON_STATE_ARRAY_VALUE:
|
jbe@152
|
598 // get current array length:
|
jbe@152
|
599 arraylen = lua_rawlen(L, -3);
|
jbe@152
|
600 // throw error if array would exceed INT_MAX elements:
|
jbe@152
|
601 // TODO: Lua 5.3 may support more elements
|
jbe@152
|
602 if (arraylen >= INT_MAX) {
|
jbe@152
|
603 lua_pushnil(L);
|
jbe@152
|
604 lua_pushfstring(L, "Array exceeded length of %d elements", INT_MAX);
|
jbe@152
|
605 }
|
jbe@136
|
606 // store value in outer shadow table:
|
jbe@152
|
607 lua_rawseti(L, -3, arraylen + 1);
|
jbe@146
|
608 // expect value terminator (or end of object) to follow:
|
jbe@124
|
609 mode = JSON_STATE_ARRAY_SEPARATOR;
|
jbe@146
|
610 // continue with loop
|
jbe@121
|
611 goto json_import_loop;
|
jbe@136
|
612 // a single value has been read:
|
jbe@124
|
613 case JSON_STATE_VALUE:
|
jbe@136
|
614 // leave value on top of stack, expect end of JSON document, and continue with loop:
|
jbe@124
|
615 mode = JSON_STATE_END;
|
jbe@121
|
616 goto json_import_loop;
|
jbe@121
|
617 }
|
jbe@146
|
618 // syntax error handling (reachable by goto statement):
|
jbe@136
|
619 json_import_syntax_error:
|
jbe@121
|
620 lua_pushnil(L);
|
jbe@121
|
621 lua_pushliteral(L, "Syntax error in JSON document");
|
jbe@121
|
622 return 2;
|
jbe@121
|
623 }
|
jbe@121
|
624
|
jbe@146
|
625 // gets a value or its type from a JSON document (passed as first argument)
|
jbe@175
|
626 // using a path (passed as variable number of keys after the first argument):
|
jbe@137
|
627 static int json_path(lua_State *L, int type_mode) {
|
jbe@193
|
628 int stacktop; // number of arguments
|
jbe@193
|
629 int idx = 2; // stack index of current argument to process
|
jbe@173
|
630 // require at least one argument:
|
jbe@173
|
631 luaL_checkany(L, 1);
|
jbe@193
|
632 // store stack index of top of stack (number of arguments):
|
jbe@138
|
633 stacktop = lua_gettop(L);
|
jbe@146
|
634 // use first argument as "current value" (stored on top of stack):
|
jbe@193
|
635 lua_pushvalue(L, 1);
|
jbe@146
|
636 // process each "path key" (2nd argument and following arguments):
|
jbe@138
|
637 while (idx <= stacktop) {
|
jbe@146
|
638 // if "current value" (on top of stack) is nil, then the path cannot be walked and nil is returned:
|
jbe@137
|
639 if (lua_isnil(L, -1)) return 1;
|
jbe@137
|
640 // try to get shadow table of "current value":
|
jbe@193
|
641 json_getshadow(L, -1);
|
jbe@126
|
642 if (lua_isnil(L, -1)) {
|
jbe@137
|
643 // if no shadow table is found,
|
jbe@193
|
644 if (lua_type(L, -2) == LUA_TTABLE) {
|
jbe@146
|
645 // and if "current value" is a table,
|
jbe@193
|
646 // pop nil from stack:
|
jbe@146
|
647 lua_pop(L, 1);
|
jbe@137
|
648 // get "next value" using the "path key":
|
jbe@130
|
649 lua_pushvalue(L, idx++);
|
jbe@130
|
650 lua_gettable(L, -2);
|
jbe@130
|
651 } else {
|
jbe@137
|
652 // if "current value" is not a table,
|
jbe@146
|
653 // then the path cannot be walked and nil (already on top of stack) is returned:
|
jbe@137
|
654 return 1;
|
jbe@130
|
655 }
|
jbe@130
|
656 } else {
|
jbe@137
|
657 // if a shadow table is found,
|
jbe@137
|
658 // set "current value" to its shadow table:
|
jbe@130
|
659 lua_replace(L, -2);
|
jbe@137
|
660 // get "next value" using the "path key":
|
jbe@130
|
661 lua_pushvalue(L, idx++);
|
jbe@130
|
662 lua_rawget(L, -2);
|
jbe@126
|
663 }
|
jbe@137
|
664 // the "next value" replaces the "current value":
|
jbe@130
|
665 lua_replace(L, -2);
|
jbe@126
|
666 }
|
jbe@137
|
667 if (!type_mode) {
|
jbe@137
|
668 // if a value (and not its type) was requested,
|
jbe@137
|
669 // check if value is the null-marker, and store nil on top of Lua stack in that case:
|
jbe@155
|
670 if (json_isnullmark(L, -1)) lua_pushnil(L);
|
jbe@137
|
671 } else {
|
jbe@137
|
672 // if the type was requested,
|
jbe@137
|
673 // check if value is the null-marker:
|
jbe@155
|
674 if (json_isnullmark(L, -1)) {
|
jbe@137
|
675 // if yes, store string "null" on top of Lua stack:
|
jbe@130
|
676 lua_pushliteral(L, "null");
|
jbe@137
|
677 } else {
|
jbe@137
|
678 // otherwise,
|
jbe@138
|
679 // check if metatable indicates "object" or "array":
|
jbe@138
|
680 if (lua_getmetatable(L, -1)) {
|
jbe@144
|
681 json_regfetch(L, objectmt);
|
jbe@138
|
682 if (lua_rawequal(L, -2, -1)) {
|
jbe@146
|
683 // if value has metatable for JSON objects,
|
jbe@138
|
684 // return string "object":
|
jbe@138
|
685 lua_pushliteral(L, "object");
|
jbe@138
|
686 return 1;
|
jbe@138
|
687 }
|
jbe@144
|
688 json_regfetch(L, arraymt);
|
jbe@138
|
689 if (lua_rawequal(L, -3, -1)) {
|
jbe@146
|
690 // if value has metatable for JSON arrays,
|
jbe@146
|
691 // return string "object":
|
jbe@138
|
692 lua_pushliteral(L, "array");
|
jbe@138
|
693 return 1;
|
jbe@138
|
694 }
|
jbe@146
|
695 // remove 3 metatables (one of the value, two for comparison) from stack:
|
jbe@138
|
696 lua_pop(L, 3);
|
jbe@138
|
697 }
|
jbe@138
|
698 // otherwise, get the Lua type:
|
jbe@138
|
699 lua_pushstring(L, lua_typename(L, lua_type(L, -1)));
|
jbe@126
|
700 }
|
jbe@126
|
701 }
|
jbe@137
|
702 // return the top most value on the Lua stack:
|
jbe@137
|
703 return 1;
|
jbe@130
|
704 }
|
jbe@130
|
705
|
jbe@147
|
706 // gets a value from a JSON document (passed as first argument)
|
jbe@175
|
707 // using a path (passed as variable number of keys after the first argument):
|
jbe@130
|
708 static int json_get(lua_State *L) {
|
jbe@137
|
709 return json_path(L, 0);
|
jbe@130
|
710 }
|
jbe@130
|
711
|
jbe@147
|
712 // gets a value's type from a JSON document (passed as first argument)
|
jbe@175
|
713 // using a path (passed as variable number of keys after first the argument):
|
jbe@130
|
714 static int json_type(lua_State *L) {
|
jbe@137
|
715 return json_path(L, 1);
|
jbe@130
|
716 }
|
jbe@130
|
717
|
jbe@173
|
718 // special Lua stack indicies for json_set function:
|
jbe@193
|
719 #define json_set_objectmt_idx 1
|
jbe@193
|
720 #define json_set_arraymt_idx 2
|
jbe@173
|
721
|
jbe@173
|
722 // stack offset of arguments to json_set function:
|
jbe@193
|
723 #define json_set_idxshift 2
|
jbe@173
|
724
|
jbe@173
|
725 // sets a value (passed as second argument) in a JSON document (passed as first argument)
|
jbe@175
|
726 // using a path (passed as variable number of keys starting at third argument):
|
jbe@173
|
727 static int json_set(lua_State *L) {
|
jbe@193
|
728 int stacktop; // stack index of top of stack (after shifting)
|
jbe@193
|
729 int idx; // stack index of current argument to process
|
jbe@199
|
730 // require at least three arguments:
|
jbe@173
|
731 luaL_checkany(L, 1);
|
jbe@173
|
732 luaL_checkany(L, 2);
|
jbe@199
|
733 luaL_checkany(L, 3);
|
jbe@193
|
734 // insert objectmt into stack at position 1 (shifting the arguments):
|
jbe@173
|
735 json_regfetch(L, objectmt);
|
jbe@193
|
736 lua_insert(L, 1);
|
jbe@193
|
737 // insert arraymt into stack at position 2 (shifting the arguments):
|
jbe@193
|
738 json_regfetch(L, arraymt);
|
jbe@173
|
739 lua_insert(L, 2);
|
jbe@173
|
740 // store stack index of top of stack:
|
jbe@173
|
741 stacktop = lua_gettop(L);
|
jbe@173
|
742 // use nil as initial "parent value":
|
jbe@173
|
743 lua_pushnil(L);
|
jbe@173
|
744 // use first argument as "current value":
|
jbe@173
|
745 lua_pushvalue(L, 1 + json_set_idxshift);
|
jbe@173
|
746 // set all necessary values in path:
|
jbe@173
|
747 for (idx = 3 + json_set_idxshift; idx<=stacktop; idx++) {
|
jbe@173
|
748 // push metatable of "current value" onto stack:
|
jbe@173
|
749 if (!lua_getmetatable(L, -1)) lua_pushnil(L);
|
jbe@173
|
750 // distinguish according to type of path key:
|
jbe@173
|
751 switch (lua_type(L, idx)) {
|
jbe@173
|
752 case LUA_TSTRING:
|
jbe@173
|
753 // if path key is a string,
|
jbe@173
|
754 // check if "current value" is a JSON object (or table without metatable):
|
jbe@173
|
755 if (
|
jbe@173
|
756 lua_rawequal(L, -1, json_set_objectmt_idx) ||
|
jbe@173
|
757 (lua_isnil(L, -1) && lua_type(L, -2) == LUA_TTABLE)
|
jbe@173
|
758 ) {
|
jbe@173
|
759 // if "current value" is acceptable,
|
jbe@173
|
760 // pop metatable and leave "current value" on top of stack:
|
jbe@173
|
761 lua_pop(L, 1);
|
jbe@173
|
762 } else {
|
jbe@173
|
763 // if "current value" is not acceptable:
|
jbe@173
|
764 // pop metatable and "current value":
|
jbe@173
|
765 lua_pop(L, 2);
|
jbe@173
|
766 // throw error if parent element does not exist:
|
jbe@173
|
767 if (lua_isnil(L, -1)) return luaL_error(L, "Root element is not a JSON object");
|
jbe@173
|
768 // push new JSON object as "current value" onto stack:
|
jbe@193
|
769 json_createproxy(L);
|
jbe@173
|
770 // create and register shadow table:
|
jbe@173
|
771 lua_newtable(L);
|
jbe@193
|
772 json_setshadow(L, -2);
|
jbe@173
|
773 // set metatable of JSON object:
|
jbe@173
|
774 lua_pushvalue(L, json_set_objectmt_idx);
|
jbe@173
|
775 lua_setmetatable(L, -2);
|
jbe@173
|
776 // set entry in "parent value":
|
jbe@173
|
777 lua_pushvalue(L, idx-1);
|
jbe@173
|
778 lua_pushvalue(L, -2);
|
jbe@173
|
779 lua_settable(L, -4);
|
jbe@173
|
780 }
|
jbe@173
|
781 break;
|
jbe@173
|
782 case LUA_TNUMBER:
|
jbe@173
|
783 // if path key is a number,
|
jbe@173
|
784 // check if "current value" is a JSON array (or table without metatable):
|
jbe@173
|
785 if (
|
jbe@173
|
786 lua_rawequal(L, -1, json_set_arraymt_idx) ||
|
jbe@173
|
787 (lua_isnil(L, -1) && lua_type(L, -2) == LUA_TTABLE)
|
jbe@173
|
788 ) {
|
jbe@173
|
789 // if "current value" is acceptable,
|
jbe@173
|
790 // pop metatable and leave "current value" on top of stack:
|
jbe@173
|
791 lua_pop(L, 1);
|
jbe@173
|
792 } else {
|
jbe@173
|
793 // if "current value" is not acceptable:
|
jbe@173
|
794 // pop metatable and "current value":
|
jbe@173
|
795 lua_pop(L, 2);
|
jbe@173
|
796 // throw error if parent element does not exist:
|
jbe@173
|
797 if (lua_isnil(L, -1)) return luaL_error(L, "Root element is not a JSON array");
|
jbe@173
|
798 // push new JSON array as "current value" onto stack:
|
jbe@193
|
799 json_createproxy(L);
|
jbe@173
|
800 // create and register shadow table:
|
jbe@173
|
801 lua_newtable(L);
|
jbe@193
|
802 json_setshadow(L, -2);
|
jbe@173
|
803 // set metatable of JSON array:
|
jbe@173
|
804 lua_pushvalue(L, json_set_arraymt_idx);
|
jbe@173
|
805 lua_setmetatable(L, -2);
|
jbe@173
|
806 // set entry in "parent value":
|
jbe@173
|
807 lua_pushvalue(L, idx-1);
|
jbe@173
|
808 lua_pushvalue(L, -2);
|
jbe@173
|
809 lua_settable(L, -4);
|
jbe@173
|
810 }
|
jbe@173
|
811 break;
|
jbe@173
|
812 default:
|
jbe@173
|
813 return luaL_error(L, "Invalid path key of type %s", lua_typename(L, lua_type(L, idx)));
|
jbe@173
|
814 }
|
jbe@173
|
815 // check if last path element is being processed:
|
jbe@173
|
816 if (idx == stacktop) {
|
jbe@173
|
817 // if the last path element is being processed,
|
jbe@173
|
818 // set last path value in "current value" container:
|
jbe@173
|
819 lua_pushvalue(L, idx);
|
jbe@173
|
820 lua_pushvalue(L, 2 + json_set_idxshift);
|
jbe@173
|
821 lua_settable(L, -3);
|
jbe@173
|
822 } else {
|
jbe@173
|
823 // if the processed path element is not the last,
|
jbe@173
|
824 // use old "current value" as new "parent value"
|
jbe@173
|
825 lua_remove(L, -2);
|
jbe@173
|
826 // push new "current value" onto stack by performing a lookup:
|
jbe@173
|
827 lua_pushvalue(L, idx);
|
jbe@173
|
828 lua_gettable(L, -2);
|
jbe@173
|
829 }
|
jbe@173
|
830 }
|
jbe@173
|
831 // return first argument for convenience:
|
jbe@173
|
832 lua_settop(L, 1 + json_set_idxshift);
|
jbe@173
|
833 return 1;
|
jbe@173
|
834 }
|
jbe@173
|
835
|
jbe@147
|
836 // returns the length of a JSON array (or zero for a table without numeric keys):
|
jbe@130
|
837 static int json_len(lua_State *L) {
|
jbe@201
|
838 // require table as first argument:
|
jbe@201
|
839 luaL_checktype(L, 1, LUA_TTABLE);
|
jbe@147
|
840 // stack shall contain one function argument:
|
jbe@130
|
841 lua_settop(L, 1);
|
jbe@193
|
842 // push shadow table or nil onto stack:
|
jbe@193
|
843 json_getshadow(L, 1);
|
jbe@193
|
844 // pop nil from stack if no shadow table has been found:
|
jbe@193
|
845 if (lua_isnil(L, -1)) lua_pop(L, 1);
|
jbe@193
|
846 // return length of argument or shadow table:
|
jbe@193
|
847 lua_pushnumber(L, lua_rawlen(L, -1));
|
jbe@123
|
848 return 1;
|
jbe@123
|
849 }
|
jbe@123
|
850
|
jbe@175
|
851 // __index metamethod for JSON objects and JSON arrays:
|
jbe@130
|
852 static int json_index(lua_State *L) {
|
jbe@201
|
853 // require table as first argument:
|
jbe@201
|
854 luaL_checktype(L, 1, LUA_TTABLE);
|
jbe@148
|
855 // stack shall contain two function arguments:
|
jbe@130
|
856 lua_settop(L, 2);
|
jbe@193
|
857 // replace first argument with its shadow table
|
jbe@193
|
858 // or throw error if no shadow table is found:
|
jbe@193
|
859 json_getshadow(L, 1);
|
jbe@139
|
860 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@193
|
861 lua_replace(L, 1);
|
jbe@148
|
862 // use key passed as second argument to lookup value in shadow table:
|
jbe@193
|
863 lua_rawget(L, 1);
|
jbe@148
|
864 // if value is null-marker, then push nil onto stack:
|
jbe@193
|
865 if (json_isnullmark(L, 2)) lua_pushnil(L);
|
jbe@148
|
866 // return either looked up value, or nil
|
jbe@127
|
867 return 1;
|
jbe@127
|
868 }
|
jbe@127
|
869
|
jbe@175
|
870 // __newindex metamethod for JSON objects and JSON arrays:
|
jbe@130
|
871 static int json_newindex(lua_State *L) {
|
jbe@201
|
872 // require table as first argument
|
jbe@201
|
873 luaL_checktype(L, 1, LUA_TTABLE);
|
jbe@148
|
874 // stack shall contain three function arguments:
|
jbe@130
|
875 lua_settop(L, 3);
|
jbe@193
|
876 // replace first argument with its shadow table
|
jbe@193
|
877 // or throw error if no shadow table is found:
|
jbe@193
|
878 json_getshadow(L, 1);
|
jbe@130
|
879 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@130
|
880 lua_replace(L, 1);
|
jbe@193
|
881 // second and third argument to write to shadow table:
|
jbe@130
|
882 lua_rawset(L, 1);
|
jbe@148
|
883 // return nothing:
|
jbe@148
|
884 return 0;
|
jbe@121
|
885 }
|
jbe@121
|
886
|
jbe@175
|
887 // function returned as first value by json_pairs function:
|
jbe@135
|
888 static int json_pairs_iterfunc(lua_State *L) {
|
jbe@201
|
889 // require table as first argument
|
jbe@201
|
890 luaL_checktype(L, 1, LUA_TTABLE);
|
jbe@149
|
891 // stack shall contain two function arguments:
|
jbe@135
|
892 lua_settop(L, 2);
|
jbe@200
|
893 // get next key value pair from shadow table (argument 1) using previous key (argument 2)
|
jbe@149
|
894 // and return nothing if there is no next pair:
|
jbe@193
|
895 if (!lua_next(L, 1)) return 0;
|
jbe@149
|
896 // replace null-marker with nil:
|
jbe@155
|
897 if (json_isnullmark(L, -1)) {
|
jbe@135
|
898 lua_pop(L, 1);
|
jbe@135
|
899 lua_pushnil(L);
|
jbe@135
|
900 }
|
jbe@149
|
901 // return key and value (or key and nil, if null-marker was found):
|
jbe@135
|
902 return 2;
|
jbe@135
|
903 }
|
jbe@135
|
904
|
jbe@149
|
905 // returns a triple such that 'for key, value in pairs(obj) do ... end'
|
jbe@175
|
906 // iterates through all key value pairs (including JSON null values represented as Lua nil):
|
jbe@135
|
907 static int json_pairs(lua_State *L) {
|
jbe@201
|
908 // require table as first argument
|
jbe@201
|
909 luaL_checktype(L, 1, LUA_TTABLE);
|
jbe@200
|
910 // return triple of function json_pairs_iterfunc, shadow table of first argument, and nil:
|
jbe@139
|
911 lua_pushcfunction(L, json_pairs_iterfunc);
|
jbe@200
|
912 json_getshadow(L, 1);
|
jbe@200
|
913 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@135
|
914 lua_pushnil(L);
|
jbe@135
|
915 return 3;
|
jbe@135
|
916 }
|
jbe@135
|
917
|
jbe@175
|
918 // function returned as first value by json_ipairs function:
|
jbe@134
|
919 static int json_ipairs_iterfunc(lua_State *L) {
|
jbe@152
|
920 lua_Integer idx;
|
jbe@201
|
921 // require table as first argument
|
jbe@201
|
922 luaL_checktype(L, 1, LUA_TTABLE);
|
jbe@149
|
923 // stack shall contain two function arguments:
|
jbe@134
|
924 lua_settop(L, 2);
|
jbe@149
|
925 // calculate new index by incrementing second argument:
|
jbe@134
|
926 idx = lua_tointeger(L, 2) + 1;
|
jbe@200
|
927 // do integer lookup in shadow table and store result on stack position 3:
|
jbe@200
|
928 lua_rawgeti(L, 1, idx);
|
jbe@149
|
929 // return nothing if there was no value:
|
jbe@200
|
930 if (lua_isnil(L, 3)) return 0;
|
jbe@149
|
931 // return new index and
|
jbe@149
|
932 // either the looked up value if it is not equal to the null-marker
|
jbe@149
|
933 // or nil instead of null-marker:
|
jbe@134
|
934 lua_pushinteger(L, idx);
|
jbe@200
|
935 if (json_isnullmark(L, 3)) lua_pushnil(L);
|
jbe@200
|
936 else lua_pushvalue(L, 3);
|
jbe@134
|
937 return 2;
|
jbe@134
|
938 }
|
jbe@134
|
939
|
jbe@149
|
940 // returns a triple such that 'for idx, value in ipairs(ary) do ... end'
|
jbe@175
|
941 // iterates through all values (including JSON null values represented as Lua nil):
|
jbe@134
|
942 static int json_ipairs(lua_State *L) {
|
jbe@201
|
943 // require table as first argument
|
jbe@201
|
944 luaL_checktype(L, 1, LUA_TTABLE);
|
jbe@200
|
945 // return triple of function json_ipairs_iterfunc, shadow table of first argument, and zero:
|
jbe@139
|
946 lua_pushcfunction(L, json_ipairs_iterfunc);
|
jbe@200
|
947 json_getshadow(L, 1);
|
jbe@200
|
948 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@134
|
949 lua_pushinteger(L, 0);
|
jbe@134
|
950 return 3;
|
jbe@134
|
951 }
|
jbe@134
|
952
|
jbe@175
|
953 // datatype representing a table key:
|
jbe@175
|
954 // (used for sorting)
|
jbe@163
|
955 typedef struct {
|
jbe@163
|
956 size_t length;
|
jbe@163
|
957 const char *data;
|
jbe@163
|
958 } json_key_t;
|
jbe@163
|
959
|
jbe@175
|
960 // comparation function for table keys to be passed to qsort function:
|
jbe@163
|
961 static int json_key_cmp(json_key_t *key1, json_key_t *key2) {
|
jbe@163
|
962 size_t pos = 0;
|
jbe@163
|
963 unsigned char c1, c2;
|
jbe@163
|
964 while (1) {
|
jbe@163
|
965 if (key1->length > pos) {
|
jbe@163
|
966 if (key2->length > pos) {
|
jbe@163
|
967 c1 = key1->data[pos];
|
jbe@163
|
968 c2 = key2->data[pos];
|
jbe@163
|
969 if (c1 < c2) return -1;
|
jbe@163
|
970 else if (c1 > c2) return 1;
|
jbe@163
|
971 } else {
|
jbe@163
|
972 return 1;
|
jbe@163
|
973 }
|
jbe@163
|
974 } else {
|
jbe@163
|
975 if (key2->length > pos) {
|
jbe@163
|
976 return -1;
|
jbe@163
|
977 } else {
|
jbe@163
|
978 return 0;
|
jbe@163
|
979 }
|
jbe@163
|
980 }
|
jbe@163
|
981 pos++;
|
jbe@163
|
982 }
|
jbe@163
|
983 }
|
jbe@163
|
984
|
jbe@175
|
985 // constants for type detection of ambiguous tables:
|
jbe@154
|
986 #define JSON_TABLETYPE_UNKNOWN 0
|
jbe@154
|
987 #define JSON_TABLETYPE_OBJECT 1
|
jbe@154
|
988 #define JSON_TABLETYPE_ARRAY 2
|
jbe@154
|
989
|
jbe@183
|
990 typedef struct {
|
jbe@183
|
991 int type;
|
jbe@183
|
992 int pos;
|
jbe@183
|
993 int count;
|
jbe@183
|
994 json_key_t keys[1]; // or more
|
jbe@183
|
995 } json_container_t;
|
jbe@183
|
996
|
jbe@183
|
997 // special Lua stack indicies for json_export function:
|
jbe@183
|
998 #define json_export_value_idx 1
|
jbe@183
|
999 #define json_export_indentstring_idx 2
|
jbe@183
|
1000 #define json_export_objectmt_idx 3
|
jbe@183
|
1001 #define json_export_arraymt_idx 4
|
jbe@193
|
1002 #define json_export_stackswap_idx 5
|
jbe@193
|
1003 #define json_export_luacontainer_idx 6
|
jbe@193
|
1004 #define json_export_ccontainer_idx 7
|
jbe@193
|
1005 #define json_export_buffer_idx 8
|
jbe@164
|
1006
|
jbe@183
|
1007 // encodes a JSON document (passed as first argument)
|
jbe@187
|
1008 // optionally using indentation (indentation string or true passed as second argument)
|
jbe@183
|
1009 static int json_export(lua_State *L) {
|
jbe@183
|
1010 int pretty; // pretty printing on? (i.e. printing with indentation)
|
jbe@183
|
1011 luaL_Buffer buf; // Lua buffer containing result string
|
jbe@183
|
1012 lua_Number num; // number to encode
|
jbe@190
|
1013 char numstr[21]; // encoded number (sign, zero, point, 17 significant digits, and terminating NULL byte)
|
jbe@183
|
1014 const char *str; // string to encode
|
jbe@183
|
1015 size_t strlen; // length of string to encode
|
jbe@183
|
1016 size_t strpos ; // position in string or position of current key
|
jbe@183
|
1017 unsigned char c; // character to encode (unsigned!)
|
jbe@183
|
1018 char hexcode[7]; // store for unicode hex escape sequence
|
jbe@183
|
1019 // NOTE: 7 bytes due to backslash, character 'u', 4 hex digits, and terminating NULL byte
|
jbe@183
|
1020 int tabletype; // table type: unknown, JSON object, or JSON array
|
jbe@183
|
1021 size_t keycount = 0; // number of string keys in object
|
jbe@185
|
1022 json_key_t *key; // pointer to C structure containing a string key
|
jbe@183
|
1023 int level = 0; // current depth level
|
jbe@183
|
1024 int i; // iteration variable for level dependent repetitions
|
jbe@183
|
1025 int stackswapidx = 0; // elements in stack swap table
|
jbe@183
|
1026 int containerkey = 0; // temporarily set to 1, if a container key is being encoded
|
jbe@183
|
1027 json_container_t *container = NULL; // pointer to current C struct for container information
|
jbe@183
|
1028 // stack shall contain two function arguments:
|
jbe@183
|
1029 lua_settop(L, 2);
|
jbe@188
|
1030 // check if pretty printing (with indentation) is desired:
|
jbe@188
|
1031 if (lua_toboolean(L, json_export_indentstring_idx)) {
|
jbe@188
|
1032 // if yes,
|
jbe@188
|
1033 // set pretty variable to 1:
|
jbe@188
|
1034 pretty = 1;
|
jbe@188
|
1035 // check if second argument is a boolean (true):
|
jbe@188
|
1036 if (lua_isboolean(L, json_export_indentstring_idx)) {
|
jbe@188
|
1037 // if yes,
|
jbe@188
|
1038 // use default indentation if indentation argument is boolean true:
|
jbe@188
|
1039 lua_pushliteral(L, " ");
|
jbe@188
|
1040 lua_replace(L, json_export_indentstring_idx);
|
jbe@188
|
1041 } else {
|
jbe@188
|
1042 // if no,
|
jbe@188
|
1043 // require second argument to be a string:
|
jbe@188
|
1044 luaL_checktype(L, json_export_indentstring_idx, LUA_TSTRING);
|
jbe@188
|
1045 }
|
jbe@188
|
1046 } else {
|
jbe@188
|
1047 // if no,
|
jbe@188
|
1048 // set pretty variable to 0:
|
jbe@188
|
1049 pretty = 0;
|
jbe@157
|
1050 }
|
jbe@183
|
1051 // push objectmt onto stack position 3:
|
jbe@183
|
1052 json_regfetch(L, objectmt);
|
jbe@183
|
1053 // push arraymt onto stack position 4:
|
jbe@183
|
1054 json_regfetch(L, arraymt);
|
jbe@193
|
1055 // push table for stack swapping onto stack position 5:
|
jbe@183
|
1056 lua_newtable(L);
|
jbe@193
|
1057 // create placeholders on stack positions 6 through 7:
|
jbe@187
|
1058 lua_settop(L, json_export_buffer_idx);
|
jbe@183
|
1059 // create Lua string buffer:
|
jbe@183
|
1060 luaL_buffinit(L, &buf);
|
jbe@183
|
1061 // loop:
|
jbe@183
|
1062 while (1) {
|
jbe@183
|
1063 // if value to encode is the null-marker, then treat it the same as nil:
|
jbe@183
|
1064 if (json_isnullmark(L, json_export_value_idx)) {
|
jbe@183
|
1065 lua_pushnil(L);
|
jbe@183
|
1066 lua_replace(L, json_export_value_idx);
|
jbe@164
|
1067 }
|
jbe@183
|
1068 // distinguish between different Lua types:
|
jbe@183
|
1069 switch (lua_type(L, json_export_value_idx)) {
|
jbe@183
|
1070 // value to encode is nil:
|
jbe@183
|
1071 case LUA_TNIL:
|
jbe@183
|
1072 // add string "null" to output buffer:
|
jbe@183
|
1073 luaL_addstring(&buf, "null");
|
jbe@183
|
1074 break;
|
jbe@183
|
1075 // value to encode is of type number:
|
jbe@183
|
1076 case LUA_TNUMBER:
|
jbe@183
|
1077 // convert value to double precision number:
|
jbe@183
|
1078 num = lua_tonumber(L, json_export_value_idx);
|
jbe@183
|
1079 // throw error if number is not-a-number:
|
jbe@183
|
1080 if (isnan(num)) return luaL_error(L, "JSON export not possible for NaN value");
|
jbe@183
|
1081 // throw error if number is positive or negative infinity:
|
jbe@183
|
1082 if (isinf(num)) return luaL_error(L, "JSON export not possible for infinite numbers");
|
jbe@191
|
1083 // determine necessary precision to represent double precision floating point number:
|
jbe@192
|
1084 sprintf(numstr, "%.16g", num);
|
jbe@191
|
1085 if (strtod(numstr, NULL) != num) sprintf(numstr, "%.17g", num);
|
jbe@191
|
1086 // add string encoding of the number to the output buffer:
|
jbe@189
|
1087 luaL_addstring(&buf, numstr);
|
jbe@183
|
1088 break;
|
jbe@183
|
1089 // value to encode is of type boolean:
|
jbe@183
|
1090 case LUA_TBOOLEAN:
|
jbe@183
|
1091 // add string "true" or "false" according to boolean value:
|
jbe@183
|
1092 luaL_addstring(&buf, lua_toboolean(L, json_export_value_idx) ? "true" : "false");
|
jbe@183
|
1093 break;
|
jbe@183
|
1094 // value to encode is of type string:
|
jbe@183
|
1095 case LUA_TSTRING:
|
jbe@183
|
1096 // add quoted and escaped string to output buffer:
|
jbe@183
|
1097 str = lua_tolstring(L, json_export_value_idx, &strlen);
|
jbe@183
|
1098 luaL_addchar(&buf, '"');
|
jbe@183
|
1099 strpos = 0;
|
jbe@183
|
1100 while (strpos < strlen) {
|
jbe@183
|
1101 c = str[strpos++];
|
jbe@183
|
1102 if (c == '"') luaL_addstring(&buf, "\\\"");
|
jbe@183
|
1103 else if (c == '\\') luaL_addstring(&buf, "\\\\");
|
jbe@183
|
1104 else if (c == 127) luaL_addstring(&buf, "\\u007F");
|
jbe@183
|
1105 else if (c >= 32) luaL_addchar(&buf, c);
|
jbe@183
|
1106 else if (c == '\b') luaL_addstring(&buf, "\\b");
|
jbe@183
|
1107 else if (c == '\f') luaL_addstring(&buf, "\\f");
|
jbe@183
|
1108 else if (c == '\n') luaL_addstring(&buf, "\\n");
|
jbe@183
|
1109 else if (c == '\r') luaL_addstring(&buf, "\\r");
|
jbe@183
|
1110 else if (c == '\t') luaL_addstring(&buf, "\\t");
|
jbe@183
|
1111 else if (c == '\v') luaL_addstring(&buf, "\\v");
|
jbe@183
|
1112 else {
|
jbe@183
|
1113 sprintf(hexcode, "\\u%04X", c);
|
jbe@183
|
1114 luaL_addstring(&buf, hexcode);
|
jbe@154
|
1115 }
|
jbe@154
|
1116 }
|
jbe@183
|
1117 luaL_addchar(&buf, '"');
|
jbe@183
|
1118 break;
|
jbe@183
|
1119 // value to encode is of type table (this includes JSON objects and JSON arrays):
|
jbe@183
|
1120 case LUA_TTABLE:
|
jbe@183
|
1121 // use table's metatable to try to determine type of table:
|
jbe@183
|
1122 tabletype = JSON_TABLETYPE_UNKNOWN;
|
jbe@188
|
1123 if (lua_getmetatable(L, json_export_value_idx)) {
|
jbe@183
|
1124 if (lua_rawequal(L, -1, json_export_objectmt_idx)) {
|
jbe@183
|
1125 tabletype = JSON_TABLETYPE_OBJECT;
|
jbe@183
|
1126 } else {
|
jbe@183
|
1127 if (lua_rawequal(L, -1, json_export_arraymt_idx)) {
|
jbe@183
|
1128 tabletype = JSON_TABLETYPE_ARRAY;
|
jbe@183
|
1129 } else {
|
jbe@183
|
1130 return luaL_error(L, "JSON export not possible for tables with nonsupported metatable");
|
jbe@183
|
1131 }
|
jbe@183
|
1132 }
|
jbe@183
|
1133 // reset stack (pop metatable from stack):
|
jbe@183
|
1134 lua_pop(L, 1);
|
jbe@183
|
1135 }
|
jbe@193
|
1136 // replace table with its shadow table if existent:
|
jbe@193
|
1137 json_getshadow(L, json_export_value_idx);
|
jbe@183
|
1138 if (lua_isnil(L, -1)) lua_pop(L, 1);
|
jbe@193
|
1139 else lua_replace(L, json_export_value_idx);
|
jbe@187
|
1140 // check if type of table is still undetermined
|
jbe@187
|
1141 // and optionally calculate number of string keys (keycount)
|
jbe@187
|
1142 // or set keycount to zero:
|
jbe@186
|
1143 keycount = 0;
|
jbe@183
|
1144 if (tabletype == JSON_TABLETYPE_UNKNOWN) {
|
jbe@187
|
1145 // if type of table is undetermined,
|
jbe@187
|
1146 // iterate over all keys:
|
jbe@188
|
1147 for (lua_pushnil(L); lua_next(L, json_export_value_idx); lua_pop(L, 1)) {
|
jbe@183
|
1148 switch (lua_type(L, -2)) {
|
jbe@183
|
1149 case LUA_TSTRING:
|
jbe@183
|
1150 // for string keys,
|
jbe@183
|
1151 // increase keycount (may avoid another iteration):
|
jbe@183
|
1152 keycount++;
|
jbe@183
|
1153 // if type of table was unknown, then type of table is a JSON object now:
|
jbe@183
|
1154 if (tabletype == JSON_TABLETYPE_UNKNOWN) tabletype = JSON_TABLETYPE_OBJECT;
|
jbe@183
|
1155 // if type of table was a JSON array, then the type of table is ambiguous now
|
jbe@183
|
1156 // and an error is thrown:
|
jbe@183
|
1157 else if (tabletype == JSON_TABLETYPE_ARRAY) goto json_export_tabletype_error;
|
jbe@183
|
1158 break;
|
jbe@183
|
1159 case LUA_TNUMBER:
|
jbe@183
|
1160 // for numeric keys,
|
jbe@183
|
1161 // if type of table was unknown, then type of table is a JSON array now:
|
jbe@183
|
1162 if (tabletype == JSON_TABLETYPE_UNKNOWN) tabletype = JSON_TABLETYPE_ARRAY;
|
jbe@183
|
1163 // if type of table was a JSON object, then the type of table is ambiguous now
|
jbe@183
|
1164 // and an error is thrown:
|
jbe@183
|
1165 else if (tabletype == JSON_TABLETYPE_OBJECT) goto json_export_tabletype_error;
|
jbe@183
|
1166 break;
|
jbe@183
|
1167 }
|
jbe@164
|
1168 }
|
jbe@163
|
1169 }
|
jbe@183
|
1170 // raise error if too many nested levels:
|
jbe@183
|
1171 if (level >= JSON_MAXDEPTH) {
|
jbe@183
|
1172 return luaL_error(L, "More than %d nested JSON levels", JSON_MAXDEPTH);
|
jbe@163
|
1173 }
|
jbe@183
|
1174 // store previous container information (if existent) on stack swap
|
jbe@183
|
1175 // and increase level variable:
|
jbe@183
|
1176 if (level++) {
|
jbe@183
|
1177 lua_pushvalue(L, json_export_luacontainer_idx);
|
jbe@183
|
1178 lua_rawseti(L, json_export_stackswap_idx, ++stackswapidx);
|
jbe@183
|
1179 lua_pushvalue(L, json_export_ccontainer_idx);
|
jbe@183
|
1180 lua_rawseti(L, json_export_stackswap_idx, ++stackswapidx);
|
jbe@183
|
1181 }
|
jbe@188
|
1182 // use value as current container:
|
jbe@188
|
1183 lua_pushvalue(L, json_export_value_idx);
|
jbe@188
|
1184 lua_replace(L, json_export_luacontainer_idx);
|
jbe@183
|
1185 // distinguish between JSON objects and JSON arrays:
|
jbe@183
|
1186 switch (tabletype) {
|
jbe@183
|
1187 // JSON object:
|
jbe@183
|
1188 case JSON_TABLETYPE_OBJECT:
|
jbe@183
|
1189 // calculate count of string keys unless it has been calculated before:
|
jbe@183
|
1190 if (!keycount) {
|
jbe@183
|
1191 for (lua_pushnil(L); lua_next(L, json_export_luacontainer_idx); lua_pop(L, 1)) {
|
jbe@183
|
1192 if (lua_type(L, -2) == LUA_TSTRING) keycount++;
|
jbe@164
|
1193 }
|
jbe@164
|
1194 }
|
jbe@186
|
1195 // allocate memory for C structure containing string keys and container iteration state:
|
jbe@186
|
1196 container = lua_newuserdata(L, sizeof(json_container_t) + (keycount-1) * sizeof(json_key_t));
|
jbe@187
|
1197 // store reference to C structure on designated stack position:
|
jbe@186
|
1198 lua_replace(L, json_export_ccontainer_idx);
|
jbe@186
|
1199 // initialize C structure for container state:
|
jbe@186
|
1200 container->type = JSON_TABLETYPE_OBJECT;
|
jbe@186
|
1201 container->count = keycount;
|
jbe@186
|
1202 container->pos = 0;
|
jbe@187
|
1203 // check if object contains any keys:
|
jbe@183
|
1204 if (keycount) {
|
jbe@187
|
1205 // if yes,
|
jbe@187
|
1206 // copy all string keys to the C structure (and reset container->pos again):
|
jbe@183
|
1207 for (lua_pushnil(L); lua_next(L, json_export_luacontainer_idx); lua_pop(L, 1)) {
|
jbe@183
|
1208 if (lua_type(L, -2) == LUA_TSTRING) {
|
jbe@183
|
1209 json_key_t *key = &container->keys[container->pos++];
|
jbe@183
|
1210 key->data = lua_tolstring(L, -2, &key->length);
|
jbe@183
|
1211 }
|
jbe@183
|
1212 }
|
jbe@183
|
1213 container->pos = 0;
|
jbe@183
|
1214 // sort C array using quicksort:
|
jbe@183
|
1215 qsort(container->keys, keycount, sizeof(json_key_t), (void *)json_key_cmp);
|
jbe@154
|
1216 }
|
jbe@183
|
1217 // add opening bracket to output buffer:
|
jbe@183
|
1218 luaL_addchar(&buf, '{');
|
jbe@183
|
1219 break;
|
jbe@183
|
1220 // JSON array:
|
jbe@183
|
1221 case JSON_TABLETYPE_ARRAY:
|
jbe@187
|
1222 // allocate memory for C structure for container iteration state:
|
jbe@183
|
1223 container = lua_newuserdata(L, sizeof(json_container_t) - sizeof(json_key_t));
|
jbe@187
|
1224 // store reference to C structure on designated stack position:
|
jbe@183
|
1225 lua_replace(L, json_export_ccontainer_idx);
|
jbe@187
|
1226 // initialize C structure for container state:
|
jbe@183
|
1227 container->type = JSON_TABLETYPE_ARRAY;
|
jbe@183
|
1228 container->pos = 0;
|
jbe@183
|
1229 // add opening bracket to output buffer:
|
jbe@183
|
1230 luaL_addchar(&buf, '[');
|
jbe@183
|
1231 break;
|
jbe@183
|
1232 default:
|
jbe@183
|
1233 // throw error if table type is unknown:
|
jbe@183
|
1234 json_export_tabletype_error:
|
jbe@183
|
1235 return luaL_error(L, "JSON export not possible for ambiguous table (cannot decide whether it is an object or array)");
|
jbe@183
|
1236 }
|
jbe@183
|
1237 break;
|
jbe@183
|
1238 default:
|
jbe@183
|
1239 // all other datatypes are considered an error:
|
jbe@183
|
1240 return luaL_error(L, "JSON export not possible for values of type \"%s\"", lua_typename(L, lua_type(L, json_export_value_idx)));
|
jbe@183
|
1241 }
|
jbe@187
|
1242 // check if a container is being processed:
|
jbe@183
|
1243 if (container) {
|
jbe@187
|
1244 // if yes,
|
jbe@187
|
1245 // execute code for container iteration:
|
jbe@184
|
1246 json_export_container:
|
jbe@187
|
1247 // distinguish between JSON objects and JSON arrays:
|
jbe@183
|
1248 switch (container->type) {
|
jbe@187
|
1249 // JSON object:
|
jbe@183
|
1250 case JSON_TABLETYPE_OBJECT:
|
jbe@187
|
1251 // finish iteration if all string keys have been processed:
|
jbe@185
|
1252 if (container->pos == container->count) goto json_export_close;
|
jbe@187
|
1253 // push current string key on top of stack:
|
jbe@185
|
1254 key = &container->keys[container->pos];
|
jbe@185
|
1255 lua_pushlstring(L, key->data, key->length);
|
jbe@187
|
1256 // check if the key has already been exported:
|
jbe@185
|
1257 if (!containerkey) {
|
jbe@187
|
1258 // if no,
|
jbe@187
|
1259 // add a comma to the output buffer if necessary:
|
jbe@185
|
1260 if (container->pos) luaL_addchar(&buf, ',');
|
jbe@187
|
1261 // set containerkey variable to true:
|
jbe@185
|
1262 containerkey = 1;
|
jbe@183
|
1263 } else {
|
jbe@187
|
1264 // if a key has already been exported,
|
jbe@187
|
1265 // add a colon to the output buffer:
|
jbe@185
|
1266 luaL_addchar(&buf, ':');
|
jbe@187
|
1267 // add a space to the output buffer for pretty results:
|
jbe@185
|
1268 if (pretty) luaL_addchar(&buf, ' ');
|
jbe@187
|
1269 // replace string key on top of stack with corresponding value:
|
jbe@185
|
1270 lua_rawget(L, json_export_luacontainer_idx);
|
jbe@187
|
1271 // reset containerkey variable
|
jbe@185
|
1272 containerkey = 0;
|
jbe@187
|
1273 // increase number of processed key value pairs:
|
jbe@185
|
1274 container->pos++;
|
jbe@163
|
1275 }
|
jbe@187
|
1276 // store key or value on top of stack in designated stack position:
|
jbe@185
|
1277 lua_replace(L, json_export_value_idx);
|
jbe@183
|
1278 break;
|
jbe@187
|
1279 // JSON array:
|
jbe@183
|
1280 case JSON_TABLETYPE_ARRAY:
|
jbe@187
|
1281 // store next value in designated stack position:
|
jbe@185
|
1282 lua_rawgeti(L, json_export_luacontainer_idx, container->pos+1);
|
jbe@183
|
1283 lua_replace(L, json_export_value_idx);
|
jbe@187
|
1284 // finish iteration if value is nil:
|
jbe@185
|
1285 if (lua_isnil(L, json_export_value_idx)) goto json_export_close;
|
jbe@187
|
1286 // add a comma to the output buffer if necessary:
|
jbe@185
|
1287 if (container->pos) luaL_addchar(&buf, ',');
|
jbe@187
|
1288 // increase number of processed values:
|
jbe@185
|
1289 container->pos++;
|
jbe@183
|
1290 break;
|
jbe@187
|
1291 // common code for closing JSON objects or JSON arrays:
|
jbe@183
|
1292 json_export_close:
|
jbe@187
|
1293 // decrement level variable:
|
jbe@185
|
1294 level--;
|
jbe@187
|
1295 // handle indentation for pretty results:
|
jbe@187
|
1296 if (pretty && container->pos) {
|
jbe@187
|
1297 luaL_addchar(&buf, '\n');
|
jbe@187
|
1298 for (i=0; i<level; i++) {
|
jbe@187
|
1299 lua_pushvalue(L, json_export_indentstring_idx);
|
jbe@187
|
1300 luaL_addvalue(&buf);
|
jbe@185
|
1301 }
|
jbe@164
|
1302 }
|
jbe@187
|
1303 // add closing bracket to output buffer:
|
jbe@185
|
1304 luaL_addchar(&buf, container->type == JSON_TABLETYPE_OBJECT ? '}' : ']');
|
jbe@187
|
1305 // finish export if last level has been closed:
|
jbe@185
|
1306 if (!level) goto json_export_finish;
|
jbe@187
|
1307 // otherwise,
|
jbe@187
|
1308 // recall previous container information from stack swap
|
jbe@187
|
1309 // and set C pointer to corresponding C struct:
|
jbe@185
|
1310 lua_rawgeti(L, json_export_stackswap_idx, stackswapidx--);
|
jbe@185
|
1311 lua_replace(L, json_export_ccontainer_idx);
|
jbe@185
|
1312 container = lua_touserdata(L, json_export_ccontainer_idx);
|
jbe@185
|
1313 lua_rawgeti(L, json_export_stackswap_idx, stackswapidx--);
|
jbe@185
|
1314 lua_replace(L, json_export_luacontainer_idx);
|
jbe@187
|
1315 // repeat code for container iteration:
|
jbe@185
|
1316 goto json_export_container;
|
jbe@164
|
1317 }
|
jbe@184
|
1318 // handle indentation for pretty results:
|
jbe@185
|
1319 if (pretty && (containerkey || container->type == JSON_TABLETYPE_ARRAY)) {
|
jbe@185
|
1320 luaL_addchar(&buf, '\n');
|
jbe@185
|
1321 for (i=0; i<level; i++) {
|
jbe@185
|
1322 lua_pushvalue(L, json_export_indentstring_idx);
|
jbe@185
|
1323 luaL_addvalue(&buf);
|
jbe@164
|
1324 }
|
jbe@154
|
1325 }
|
jbe@183
|
1326 } else {
|
jbe@187
|
1327 // if no container is being processed,
|
jbe@187
|
1328 // finish export:
|
jbe@185
|
1329 json_export_finish:
|
jbe@185
|
1330 // for pretty results, add final newline character if outermost container is processed:
|
jbe@185
|
1331 if (pretty) luaL_addchar(&buf, '\n');
|
jbe@187
|
1332 // create and return Lua string from buffer contents
|
jbe@154
|
1333 luaL_pushresult(&buf);
|
jbe@154
|
1334 return 1;
|
jbe@154
|
1335 }
|
jbe@154
|
1336 }
|
jbe@164
|
1337 }
|
jbe@164
|
1338
|
jbe@149
|
1339 // functions in library module:
|
jbe@121
|
1340 static const struct luaL_Reg json_module_functions[] = {
|
jbe@133
|
1341 {"object", json_object},
|
jbe@173
|
1342 {"array", json_array},
|
jbe@121
|
1343 {"import", json_import},
|
jbe@154
|
1344 {"export", json_export},
|
jbe@173
|
1345 {"get", json_get},
|
jbe@173
|
1346 {"type", json_type},
|
jbe@173
|
1347 {"set", json_set},
|
jbe@121
|
1348 {NULL, NULL}
|
jbe@121
|
1349 };
|
jbe@121
|
1350
|
jbe@149
|
1351 // metamethods for JSON objects, JSON arrays, and unknown JSON collections (object or array):
|
jbe@126
|
1352 static const struct luaL_Reg json_metatable_functions[] = {
|
jbe@130
|
1353 {"__len", json_len},
|
jbe@130
|
1354 {"__index", json_index},
|
jbe@130
|
1355 {"__newindex", json_newindex},
|
jbe@135
|
1356 {"__pairs", json_pairs},
|
jbe@134
|
1357 {"__ipairs", json_ipairs},
|
jbe@160
|
1358 {"__tostring", json_export},
|
jbe@126
|
1359 {NULL, NULL}
|
jbe@126
|
1360 };
|
jbe@126
|
1361
|
jbe@157
|
1362 // metamethods for JSON null marker:
|
jbe@157
|
1363 static const struct luaL_Reg json_nullmark_metamethods[] = {
|
jbe@157
|
1364 {"__tostring", json_nullmark_tostring},
|
jbe@157
|
1365 {NULL, NULL}
|
jbe@157
|
1366 };
|
jbe@157
|
1367
|
jbe@149
|
1368 // initializes json library:
|
jbe@121
|
1369 int luaopen_json(lua_State *L) {
|
jbe@149
|
1370 // empty stack:
|
jbe@126
|
1371 lua_settop(L, 0);
|
jbe@149
|
1372 // push library module onto stack position 1:
|
jbe@149
|
1373 lua_newtable(L);
|
jbe@149
|
1374 // register library functions:
|
jbe@149
|
1375 luaL_setfuncs(L, json_module_functions, 0);
|
jbe@149
|
1376 // create and store objectmt:
|
jbe@138
|
1377 lua_newtable(L);
|
jbe@138
|
1378 luaL_setfuncs(L, json_metatable_functions, 0);
|
jbe@144
|
1379 json_regstore(L, objectmt);
|
jbe@149
|
1380 // create and store arraymt:
|
jbe@138
|
1381 lua_newtable(L);
|
jbe@138
|
1382 luaL_setfuncs(L, json_metatable_functions, 0);
|
jbe@144
|
1383 json_regstore(L, arraymt);
|
jbe@157
|
1384 // set metatable of null marker and make it available through library module:
|
jbe@157
|
1385 json_pushnullmark(L);
|
jbe@157
|
1386 lua_newtable(L);
|
jbe@157
|
1387 luaL_setfuncs(L, json_nullmark_metamethods, 0);
|
jbe@157
|
1388 lua_setmetatable(L, -2);
|
jbe@157
|
1389 lua_setfield(L, 1, "null");
|
jbe@157
|
1390 // return library module (that's expected on top of stack):
|
jbe@121
|
1391 return 1;
|
jbe@121
|
1392 }
|