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@150
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8 // NOTE: The Lua reference states that the stack may typically contain at least
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jbe@150
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9 // "a few thousand elements". Since every nested level consumes
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jbe@150
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10 // 3 elements on the Lua stack (the object/array, its shadow table,
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jbe@150
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11 // a string key or a placeholder), we limit the number of nested levels
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jbe@150
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12 // to 500. If a stack overflow would still happen in the import function,
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jbe@150
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13 // this is detected nevertheless and an error is thrown (instead of
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jbe@150
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14 // returning nil and an error string).
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jbe@150
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15 #define JSON_MAXDEPTH 500
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jbe@179
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16 // NOTE: As long as the function json_export_internal is implemented
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jbe@179
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17 // recursively, JSON_MAXDEPTH needs to be low (e.g. 50) to avoid C stack
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jbe@179
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18 // overflows.
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jbe@179
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19 #if JSON_MAXDEPTH > 50
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jbe@180
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20 #undef JSON_MAXDEPTH
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jbe@179
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21 #define JSON_MAXDEPTH 50
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jbe@179
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22 #endif
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jbe@142
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23
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jbe@155
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24 // generate dummy memory addresses that represents null values:
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jbe@155
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25 char json_nullmark;
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jbe@155
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26 #define json_isnullmark(L, i) (lua_touserdata((L), (i)) == &json_nullmark)
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jbe@155
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27 #define json_pushnullmark(L) lua_pushlightuserdata((L), &json_nullmark)
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jbe@155
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28
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jbe@144
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29 // macros for usage of Lua registry:
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jbe@144
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30 #define JSON_REGENT char
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jbe@145
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31 #define JSON_REGPOINTER void *
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jbe@145
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32 #define json_regpointer(x) (&json_registry.x)
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jbe@151
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33 #define json_regfetchpointer(L, x) lua_rawgetp((L), LUA_REGISTRYINDEX, (x))
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jbe@151
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34 #define json_regfetch(L, x) json_regfetchpointer(L, json_regpointer(x))
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jbe@151
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35 #define json_regstore(L, x) lua_rawsetp(L, LUA_REGISTRYINDEX, json_regpointer(x))
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jbe@145
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36
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jbe@144
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37 // generate dummy memory addresses that represent Lua objects
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jbe@145
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38 // via lightuserdata keys and LUA_REGISTRYINDEX:
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jbe@144
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39 static struct {
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jbe@145
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40 JSON_REGENT shadowtbl; // ephemeron table that maps tables to their corresponding shadow table
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jbe@145
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41 JSON_REGENT objectmt; // metatable for JSON objects
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jbe@145
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42 JSON_REGENT arraymt; // metatable for JSON arrays
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jbe@144
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43 } json_registry;
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jbe@138
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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
|
49 }
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jbe@157
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50
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jbe@169
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51 #define json_convert_source_idx 1
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jbe@169
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52 #define json_convert_iterator_idx 2
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jbe@169
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53 #define json_convert_output_idx 3
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jbe@169
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54 #define json_convert_shadow_idx 4
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jbe@172
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55 #define json_convert_iterfun_idx 5
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jbe@172
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56 #define json_convert_itertbl_idx 6
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jbe@169
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57
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jbe@175
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58 // converts a Lua table (or any other iterable value) to a JSON object or JSON array:
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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@169
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60 static int json_convert(lua_State *L, int array) {
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jbe@171
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61 int arrayidx = 0;
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jbe@171
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62 // determine is argument is given:
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jbe@169
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63 if (lua_isnoneornil(L, json_convert_source_idx)) {
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jbe@171
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64 // if no argument is given (or if argument is nil),
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jbe@171
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65 // create table with shadow table, and leave first table on top of stack:
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jbe@144
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66 json_regfetch(L, shadowtbl);
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jbe@169
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67 lua_newtable(L);
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jbe@169
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68 lua_pushvalue(L, -1);
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jbe@169
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69 lua_newtable(L);
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jbe@169
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70 lua_rawset(L, -4);
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jbe@169
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71 } else {
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jbe@171
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72 // if an argument was given,
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jbe@171
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73 // push its iterator function on stack position 2 if existent,
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jbe@169
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74 // else push null for normal tables:
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jbe@171
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75 lua_settop(L, 1);
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jbe@169
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76 if (lua_getmetatable(L, json_convert_source_idx)) {
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jbe@169
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77 lua_getfield(L, -1, array ? "__ipairs" : "__pairs");
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jbe@169
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78 if (lua_isnil(L, -1)) luaL_checktype(L, 1, LUA_TTABLE);
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jbe@169
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79 else if (lua_type(L, -1) != LUA_TFUNCTION)
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jbe@169
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80 return luaL_error(L, "%s metamethod is not a function", array ? "__ipairs" : "__pairs");
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jbe@169
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81 lua_replace(L, -2);
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jbe@169
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82 } else {
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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@169
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86 lua_newtable(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 json_regfetch(L, shadowtbl);
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jbe@169
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89 lua_newtable(L);
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jbe@169
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90 lua_pushvalue(L, json_convert_output_idx);
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jbe@169
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91 lua_pushvalue(L, -2);
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jbe@169
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92 lua_rawset(L, -4);
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jbe@169
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93 lua_replace(L, -2);
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jbe@171
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94 // check if iterator function exists:
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jbe@169
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95 if (lua_isnil(L, json_convert_iterator_idx)) {
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jbe@171
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96 // if there is no iterator function,
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jbe@171
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97 // distinguish between objects and arrays:
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jbe@171
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98 if (array == 0) {
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jbe@171
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99 // for an object, copy all string key value pairs to shadow table:
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jbe@171
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100 for (lua_pushnil(L); lua_next(L, json_convert_source_idx); lua_pop(L, 1)) {
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jbe@171
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101 if (lua_type(L, -2) == LUA_TSTRING) {
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jbe@171
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102 lua_pushvalue(L, -2);
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jbe@171
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103 lua_pushvalue(L, -2);
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jbe@171
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104 lua_rawset(L, json_convert_shadow_idx);
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jbe@171
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105 }
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jbe@171
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106 }
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jbe@171
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107 } else {
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jbe@171
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108 // for an array, copy consecutive integer value pairs to shadow table:
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jbe@171
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109 while (1) {
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jbe@175
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110 // throw error if array would exceed INT_MAX elements:
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jbe@171
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111 // TODO: Lua 5.3 may support more elements
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jbe@171
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112 if (arrayidx == INT_MAX) {
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jbe@171
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113 lua_pushnumber(L, (size_t)INT_MAX+1);
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jbe@171
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114 lua_rawget(L, json_convert_source_idx);
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jbe@171
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115 if (lua_isnil(L, -1)) break;
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jbe@171
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116 return luaL_error(L, "Array exceeded length of %d elements", INT_MAX);
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jbe@171
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117 }
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jbe@175
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118 // get next array entry:
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jbe@171
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119 arrayidx++;
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jbe@171
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120 lua_rawgeti(L, json_convert_source_idx, arrayidx);
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jbe@175
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121 // break if value is nil:
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jbe@171
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122 if (lua_isnil(L, -1)) break;
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jbe@175
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123 // store value in shadow table:
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jbe@171
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124 lua_rawseti(L, json_convert_shadow_idx, arrayidx);
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jbe@171
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125 }
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jbe@169
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126 }
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jbe@169
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127 } else {
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jbe@172
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128 // if there is an iterator function,
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jbe@172
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129 // call iterator function with source value (first argument)
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jbe@172
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130 // and store 3 result values on stack positions 5 through 7:
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jbe@172
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131 lua_pushvalue(L, json_convert_iterator_idx);
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jbe@172
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132 lua_pushvalue(L, 1);
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jbe@172
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133 lua_call(L, 1, 3);
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jbe@175
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134 // iterate through key value pairs and store some of them in shadow table
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jbe@174
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135 // while replacing nil values with null-marker:
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jbe@172
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136 while (1) {
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jbe@175
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137 // call iterfun function:
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jbe@172
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138 lua_pushvalue(L, json_convert_iterfun_idx);
|
jbe@172
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139 lua_pushvalue(L, json_convert_itertbl_idx);
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jbe@172
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140 lua_pushvalue(L, -3);
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jbe@172
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141 lua_remove(L, -4);
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jbe@172
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142 lua_call(L, 2, 2);
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jbe@175
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143 // break iteration loop if key is nil:
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jbe@172
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144 if (lua_isnil(L, -2)) break;
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jbe@175
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145 // store key value pair only if key type is correct:
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jbe@172
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146 if (lua_type(L, -2) == (array ? LUA_TNUMBER : LUA_TSTRING)) {
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jbe@175
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147 // if key type is correct,
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jbe@175
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148 // push key onto stack:
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jbe@172
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149 lua_pushvalue(L, -2);
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jbe@175
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150 // if value is nil, push null-marker onto stack (as value):
|
jbe@174
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151 if (lua_isnil(L, -2)) json_pushnullmark(L);
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jbe@175
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152 // else push value onto stack:
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jbe@174
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153 else lua_pushvalue(L, -2);
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jbe@175
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154 // set key value pair in shadow table:
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jbe@172
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155 lua_rawset(L, json_convert_shadow_idx);
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jbe@172
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156 }
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jbe@175
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157 // pop value from stack, but leave key on stack:
|
jbe@172
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158 lua_pop(L, 1);
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jbe@172
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159 }
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jbe@143
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160 }
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jbe@171
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161 // let result table be on top of stack:
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jbe@169
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162 lua_settop(L, json_convert_output_idx);
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jbe@136
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163 }
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jbe@171
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164 // set metatable (for result table on top of stack):
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jbe@171
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165 if (array == 0) json_regfetch(L, objectmt);
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jbe@171
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166 else json_regfetch(L, arraymt);
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jbe@169
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167 lua_setmetatable(L, -2);
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jbe@171
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168 // return table on top of stack:
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jbe@136
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169 return 1;
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jbe@136
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170 }
|
jbe@136
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171
|
jbe@175
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172 // converts a Lua table (or any other iterable value) to a JSON object:
|
jbe@175
|
173 // (does never modify the argument, returns an empty object or array if argument is nil)
|
jbe@136
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174 static int json_object(lua_State *L) {
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jbe@169
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175 return json_convert(L, 0);
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jbe@136
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176 }
|
jbe@136
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177
|
jbe@175
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178 // converts a Lua table (or any other iterable value) to a JSON array:
|
jbe@175
|
179 // (does never modify the argument, returns an empty object or array if argument is nil)
|
jbe@136
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180 static int json_array(lua_State *L) {
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jbe@169
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181 return json_convert(L, 1);
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jbe@136
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182 }
|
jbe@136
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183
|
jbe@145
|
184 // internal states of JSON parser:
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jbe@124
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185 #define JSON_STATE_VALUE 0
|
jbe@124
|
186 #define JSON_STATE_OBJECT_KEY 1
|
jbe@124
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187 #define JSON_STATE_OBJECT_KEY_TERMINATOR 2
|
jbe@124
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188 #define JSON_STATE_OBJECT_VALUE 3
|
jbe@124
|
189 #define JSON_STATE_OBJECT_SEPARATOR 4
|
jbe@124
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190 #define JSON_STATE_ARRAY_VALUE 5
|
jbe@124
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191 #define JSON_STATE_ARRAY_SEPARATOR 6
|
jbe@124
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192 #define JSON_STATE_END 7
|
jbe@121
|
193
|
jbe@145
|
194 // special Lua stack indicies for json_import function:
|
jbe@138
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195 #define json_import_objectmt_idx 2
|
jbe@138
|
196 #define json_import_arraymt_idx 3
|
jbe@138
|
197 #define json_import_shadowtbl_idx 4
|
jbe@138
|
198
|
jbe@168
|
199 // macros for hex decoding:
|
jbe@168
|
200 #define json_utf16_surrogate(x) ((x) >= 0xD800 && (x) <= 0xDFFF)
|
jbe@168
|
201 #define json_utf16_lead(x) ((x) >= 0xD800 && (x) <= 0xDBFF)
|
jbe@168
|
202 #define json_utf16_tail(x) ((x) >= 0xDC00 && (x) <= 0xDFFF)
|
jbe@167
|
203 #define json_import_readhex(x) \
|
jbe@167
|
204 do { \
|
jbe@167
|
205 x = 0; \
|
jbe@167
|
206 for (i=0; i<4; i++) { \
|
jbe@167
|
207 x <<= 4; \
|
jbe@167
|
208 c = str[pos++]; \
|
jbe@167
|
209 if (c >= '0' && c <= '9') x += c - '0'; \
|
jbe@167
|
210 else if (c >= 'A' && c <= 'F') x += c - 'A' + 10; \
|
jbe@167
|
211 else if (c >= 'a' && c <= 'f') x += c - 'a' + 10; \
|
jbe@167
|
212 else if (c == 0) goto json_import_unexpected_eof; \
|
jbe@167
|
213 else goto json_import_unexpected_escape; \
|
jbe@167
|
214 } \
|
jbe@167
|
215 } while (0)
|
jbe@167
|
216
|
jbe@136
|
217 // decodes a JSON document:
|
jbe@121
|
218 static int json_import(lua_State *L) {
|
jbe@167
|
219 int i; // loop variable
|
jbe@136
|
220 const char *str; // string to parse
|
jbe@136
|
221 size_t total; // total length of string to parse
|
jbe@136
|
222 size_t pos = 0; // current position in string to parse
|
jbe@136
|
223 size_t level = 0; // nested levels of objects/arrays currently being processed
|
jbe@145
|
224 int mode = JSON_STATE_VALUE; // state of parser (i.e. "what's expected next?")
|
jbe@170
|
225 unsigned char c; // variable to store a single character to be processed (unsigned!)
|
jbe@145
|
226 luaL_Buffer luabuf; // Lua buffer to decode JSON string values
|
jbe@145
|
227 char *cbuf; // C buffer to decode JSON string values
|
jbe@162
|
228 size_t outlen; // maximum length or write position of C buffer
|
jbe@167
|
229 long codepoint; // decoded UTF-16 character or higher codepoint
|
jbe@167
|
230 long utf16tail; // second decoded UTF-16 character (surrogate tail)
|
jbe@152
|
231 size_t arraylen; // variable to temporarily store the array length
|
jbe@166
|
232 // require string as argument and convert to C string with length information:
|
jbe@166
|
233 str = luaL_checklstring(L, 1, &total);
|
jbe@166
|
234 // if string contains a NULL byte, this is a syntax error
|
jbe@166
|
235 if (strlen(str) != total) goto json_import_syntax_error;
|
jbe@147
|
236 // stack shall contain one function argument:
|
jbe@138
|
237 lua_settop(L, 1);
|
jbe@147
|
238 // push objectmt onto stack position 2:
|
jbe@144
|
239 json_regfetch(L, objectmt);
|
jbe@147
|
240 // push arraymt onto stack position 3:
|
jbe@144
|
241 json_regfetch(L, arraymt);
|
jbe@147
|
242 // push shadowtbl onto stack position 4:
|
jbe@144
|
243 json_regfetch(L, shadowtbl);
|
jbe@136
|
244 // main loop of parser:
|
jbe@136
|
245 json_import_loop:
|
jbe@136
|
246 // skip whitespace and store next character in variable 'c':
|
jbe@146
|
247 while (c = str[pos],
|
jbe@146
|
248 c == ' ' ||
|
jbe@146
|
249 c == '\f' ||
|
jbe@146
|
250 c == '\n' ||
|
jbe@146
|
251 c == '\r' ||
|
jbe@146
|
252 c == '\t' ||
|
jbe@146
|
253 c == '\v'
|
jbe@146
|
254 ) pos++;
|
jbe@170
|
255 // NOTE: variable c needs to be unsigned in the following code
|
jbe@136
|
256 // switch statement to handle certain (single) characters:
|
jbe@121
|
257 switch (c) {
|
jbe@136
|
258 // handle end of JSON document:
|
jbe@121
|
259 case 0:
|
jbe@136
|
260 // if end of JSON document was expected, then return top element of stack as result:
|
jbe@124
|
261 if (mode == JSON_STATE_END) return 1;
|
jbe@136
|
262 // otherwise, the JSON document was malformed:
|
jbe@167
|
263 if (level == 0) {
|
jbe@167
|
264 lua_pushnil(L);
|
jbe@167
|
265 lua_pushliteral(L, "Empty string");
|
jbe@167
|
266 } else {
|
jbe@167
|
267 json_import_unexpected_eof:
|
jbe@167
|
268 lua_pushnil(L);
|
jbe@167
|
269 lua_pushliteral(L, "Unexpected end of JSON document");
|
jbe@167
|
270 }
|
jbe@121
|
271 return 2;
|
jbe@136
|
272 // new JSON object:
|
jbe@121
|
273 case '{':
|
jbe@136
|
274 // if a JSON object is not expected here, then return an error:
|
jbe@146
|
275 if (
|
jbe@146
|
276 mode != JSON_STATE_VALUE &&
|
jbe@146
|
277 mode != JSON_STATE_OBJECT_VALUE &&
|
jbe@146
|
278 mode != JSON_STATE_ARRAY_VALUE
|
jbe@146
|
279 ) goto json_import_syntax_error;
|
jbe@136
|
280 // create JSON object on stack:
|
jbe@136
|
281 lua_newtable(L);
|
jbe@136
|
282 // set metatable of JSON object:
|
jbe@138
|
283 lua_pushvalue(L, json_import_objectmt_idx);
|
jbe@125
|
284 lua_setmetatable(L, -2);
|
jbe@136
|
285 // create internal shadow table on stack:
|
jbe@136
|
286 lua_newtable(L);
|
jbe@146
|
287 // register internal shadow table:
|
jbe@123
|
288 lua_pushvalue(L, -2);
|
jbe@123
|
289 lua_pushvalue(L, -2);
|
jbe@138
|
290 lua_rawset(L, json_import_shadowtbl_idx);
|
jbe@146
|
291 // expect object key (or end of object) to follow:
|
jbe@136
|
292 mode = JSON_STATE_OBJECT_KEY;
|
jbe@146
|
293 // jump to common code for opening JSON object and JSON array:
|
jbe@142
|
294 goto json_import_open;
|
jbe@136
|
295 // new JSON array:
|
jbe@121
|
296 case '[':
|
jbe@136
|
297 // if a JSON array is not expected here, then return an error:
|
jbe@146
|
298 if (
|
jbe@146
|
299 mode != JSON_STATE_VALUE &&
|
jbe@146
|
300 mode != JSON_STATE_OBJECT_VALUE &&
|
jbe@146
|
301 mode != JSON_STATE_ARRAY_VALUE
|
jbe@146
|
302 ) goto json_import_syntax_error;
|
jbe@136
|
303 // create JSON array on stack:
|
jbe@136
|
304 lua_newtable(L);
|
jbe@136
|
305 // set metatable of JSON array:
|
jbe@138
|
306 lua_pushvalue(L, json_import_arraymt_idx);
|
jbe@125
|
307 lua_setmetatable(L, -2);
|
jbe@136
|
308 // create internal shadow table on stack:
|
jbe@136
|
309 lua_newtable(L);
|
jbe@146
|
310 // register internal shadow table:
|
jbe@123
|
311 lua_pushvalue(L, -2);
|
jbe@123
|
312 lua_pushvalue(L, -2);
|
jbe@138
|
313 lua_rawset(L, json_import_shadowtbl_idx);
|
jbe@140
|
314 // add nil as key (needed to keep stack balance) and as magic to detect arrays:
|
jbe@140
|
315 lua_pushnil(L);
|
jbe@146
|
316 // expect array value (or end of array) to follow:
|
jbe@142
|
317 mode = JSON_STATE_ARRAY_VALUE;
|
jbe@142
|
318 // continue with common code for opening JSON object and JSON array:
|
jbe@146
|
319 // common code for opening JSON object or JSON array:
|
jbe@142
|
320 json_import_open:
|
jbe@142
|
321 // limit nested levels:
|
jbe@142
|
322 if (level >= JSON_MAXDEPTH) {
|
jbe@142
|
323 lua_pushnil(L);
|
jbe@164
|
324 lua_pushfstring(L, "More than %d nested JSON levels", JSON_MAXDEPTH);
|
jbe@142
|
325 return 2;
|
jbe@142
|
326 }
|
jbe@142
|
327 // additional buffer overflow protection:
|
jbe@142
|
328 if (!lua_checkstack(L, LUA_MINSTACK))
|
jbe@142
|
329 return luaL_error(L, "Caught stack overflow in JSON import function (too many nested levels and stack size too small)");
|
jbe@136
|
330 // increment level:
|
jbe@121
|
331 level++;
|
jbe@142
|
332 // consume input character:
|
jbe@142
|
333 pos++;
|
jbe@121
|
334 goto json_import_loop;
|
jbe@136
|
335 // end of JSON object:
|
jbe@121
|
336 case '}':
|
jbe@136
|
337 // if end of JSON object is not expected here, then return an error:
|
jbe@146
|
338 if (
|
jbe@146
|
339 mode != JSON_STATE_OBJECT_KEY &&
|
jbe@146
|
340 mode != JSON_STATE_OBJECT_SEPARATOR
|
jbe@146
|
341 ) goto json_import_syntax_error;
|
jbe@136
|
342 // jump to common code for end of JSON object and JSON array:
|
jbe@121
|
343 goto json_import_close;
|
jbe@136
|
344 // end of JSON array:
|
jbe@121
|
345 case ']':
|
jbe@136
|
346 // if end of JSON array is not expected here, then return an error:
|
jbe@146
|
347 if (
|
jbe@146
|
348 mode != JSON_STATE_ARRAY_VALUE &&
|
jbe@146
|
349 mode != JSON_STATE_ARRAY_SEPARATOR
|
jbe@146
|
350 ) goto json_import_syntax_error;
|
jbe@146
|
351 // pop nil key/magic (that was needed to keep stack balance):
|
jbe@140
|
352 lua_pop(L, 1);
|
jbe@136
|
353 // continue with common code for end of JSON object and JSON array:
|
jbe@136
|
354 // common code for end of JSON object or JSON array:
|
jbe@121
|
355 json_import_close:
|
jbe@136
|
356 // consume input character:
|
jbe@121
|
357 pos++;
|
jbe@136
|
358 // pop shadow table:
|
jbe@136
|
359 lua_pop(L, 1);
|
jbe@136
|
360 // check if nested:
|
jbe@121
|
361 if (--level) {
|
jbe@146
|
362 // if nested,
|
jbe@146
|
363 // check if outer(!) structure is an array or object:
|
jbe@140
|
364 if (lua_isnil(L, -2)) {
|
jbe@136
|
365 // select array value processing:
|
jbe@124
|
366 mode = JSON_STATE_ARRAY_VALUE;
|
jbe@121
|
367 } else {
|
jbe@136
|
368 // select object value processing:
|
jbe@124
|
369 mode = JSON_STATE_OBJECT_VALUE;
|
jbe@121
|
370 }
|
jbe@136
|
371 // store value in outer structure:
|
jbe@121
|
372 goto json_import_process_value;
|
jbe@121
|
373 }
|
jbe@136
|
374 // if not nested, then expect end of JSON document and continue with loop:
|
jbe@136
|
375 mode = JSON_STATE_END;
|
jbe@121
|
376 goto json_import_loop;
|
jbe@136
|
377 // key terminator:
|
jbe@121
|
378 case ':':
|
jbe@136
|
379 // if key terminator is not expected here, then return an error:
|
jbe@124
|
380 if (mode != JSON_STATE_OBJECT_KEY_TERMINATOR)
|
jbe@121
|
381 goto json_import_syntax_error;
|
jbe@136
|
382 // consume input character:
|
jbe@121
|
383 pos++;
|
jbe@146
|
384 // expect object value to follow:
|
jbe@124
|
385 mode = JSON_STATE_OBJECT_VALUE;
|
jbe@146
|
386 // continue with loop:
|
jbe@121
|
387 goto json_import_loop;
|
jbe@136
|
388 // value terminator (NOTE: trailing comma at end of value or key-value list is tolerated by this parser)
|
jbe@121
|
389 case ',':
|
jbe@146
|
390 // branch according to parser state:
|
jbe@124
|
391 if (mode == JSON_STATE_OBJECT_SEPARATOR) {
|
jbe@146
|
392 // expect an object key to follow:
|
jbe@124
|
393 mode = JSON_STATE_OBJECT_KEY;
|
jbe@124
|
394 } else if (mode == JSON_STATE_ARRAY_SEPARATOR) {
|
jbe@146
|
395 // expect an array value to follow:
|
jbe@124
|
396 mode = JSON_STATE_ARRAY_VALUE;
|
jbe@121
|
397 } else {
|
jbe@136
|
398 // if value terminator is not expected here, then return an error:
|
jbe@136
|
399 goto json_import_syntax_error;
|
jbe@121
|
400 }
|
jbe@136
|
401 // consume input character:
|
jbe@121
|
402 pos++;
|
jbe@136
|
403 // continue with loop:
|
jbe@121
|
404 goto json_import_loop;
|
jbe@136
|
405 // string literal:
|
jbe@121
|
406 case '"':
|
jbe@146
|
407 // consume quote character:
|
jbe@146
|
408 pos++;
|
jbe@162
|
409 // find last character in input string:
|
jbe@162
|
410 outlen = pos;
|
jbe@162
|
411 while ((c = str[outlen]) != '"') {
|
jbe@161
|
412 // consume one character:
|
jbe@162
|
413 outlen++;
|
jbe@161
|
414 // handle unexpected end of JSON document:
|
jbe@161
|
415 if (c == 0) goto json_import_unexpected_eof;
|
jbe@161
|
416 // consume one extra character when encountering an escaped quote:
|
jbe@162
|
417 else if (c == '\\' && str[outlen] == '"') outlen++;
|
jbe@161
|
418 }
|
jbe@162
|
419 // determine buffer length:
|
jbe@162
|
420 outlen -= pos;
|
jbe@161
|
421 // check if string is non empty:
|
jbe@162
|
422 if (outlen) {
|
jbe@161
|
423 // prepare buffer to decode string (with maximum possible length) and set write position to zero:
|
jbe@162
|
424 cbuf = luaL_buffinitsize(L, &luabuf, outlen);
|
jbe@162
|
425 outlen = 0;
|
jbe@161
|
426 // loop through the characters until encountering end quote:
|
jbe@161
|
427 while ((c = str[pos++]) != '"') {
|
jbe@162
|
428 // NOTE: unexpected end cannot happen anymore
|
jbe@162
|
429 if (c < 32 || c == 127) {
|
jbe@161
|
430 // do not allow ASCII control characters:
|
jbe@161
|
431 // NOTE: illegal UTF-8 sequences and extended control characters are not sanitized
|
jbe@161
|
432 // by this parser to allow different encodings than Unicode
|
jbe@161
|
433 lua_pushnil(L);
|
jbe@161
|
434 lua_pushliteral(L, "Unexpected control character in JSON string");
|
jbe@161
|
435 return 2;
|
jbe@161
|
436 } else if (c == '\\') {
|
jbe@161
|
437 // read next char after backslash escape:
|
jbe@161
|
438 c = str[pos++];
|
jbe@161
|
439 switch (c) {
|
jbe@161
|
440 // unexpected end-of-string:
|
jbe@161
|
441 case 0:
|
jbe@161
|
442 goto json_import_unexpected_eof;
|
jbe@161
|
443 // unescaping of quotation mark, slash, and backslash:
|
jbe@161
|
444 case '"':
|
jbe@161
|
445 case '/':
|
jbe@161
|
446 case '\\':
|
jbe@162
|
447 cbuf[outlen++] = c;
|
jbe@161
|
448 break;
|
jbe@161
|
449 // unescaping of backspace:
|
jbe@162
|
450 case 'b': cbuf[outlen++] = '\b'; break;
|
jbe@161
|
451 // unescaping of form-feed:
|
jbe@162
|
452 case 'f': cbuf[outlen++] = '\f'; break;
|
jbe@161
|
453 // unescaping of new-line:
|
jbe@162
|
454 case 'n': cbuf[outlen++] = '\n'; break;
|
jbe@161
|
455 // unescaping of carriage-return:
|
jbe@162
|
456 case 'r': cbuf[outlen++] = '\r'; break;
|
jbe@161
|
457 // unescaping of tabulator:
|
jbe@162
|
458 case 't': cbuf[outlen++] = '\t'; break;
|
jbe@161
|
459 // unescaping of UTF-16 characters
|
jbe@161
|
460 case 'u':
|
jbe@167
|
461 // decode 4 hex nibbles:
|
jbe@167
|
462 json_import_readhex(codepoint);
|
jbe@167
|
463 // handle surrogate character:
|
jbe@167
|
464 if (json_utf16_surrogate(codepoint)) {
|
jbe@167
|
465 // check if first surrogate is in valid range:
|
jbe@167
|
466 if (json_utf16_lead(codepoint)) {
|
jbe@167
|
467 // require second surrogate:
|
jbe@167
|
468 if ((c = str[pos++]) != '\\' || (c = str[pos++]) != 'u') {
|
jbe@167
|
469 if (c == 0) goto json_import_unexpected_eof;
|
jbe@167
|
470 else goto json_import_wrong_surrogate;
|
jbe@167
|
471 }
|
jbe@167
|
472 // read 4 hex nibbles of second surrogate character:
|
jbe@167
|
473 json_import_readhex(utf16tail);
|
jbe@167
|
474 // check if second surrogate is in valid range:
|
jbe@167
|
475 if (!json_utf16_tail(utf16tail)) goto json_import_wrong_surrogate;
|
jbe@167
|
476 // calculate codepoint:
|
jbe@167
|
477 codepoint = 0x10000 + (utf16tail - 0xDC00) + (codepoint - 0xD800) * 0x400;
|
jbe@167
|
478 } else {
|
jbe@167
|
479 // throw error for wrong surrogates:
|
jbe@167
|
480 json_import_wrong_surrogate:
|
jbe@167
|
481 lua_pushnil(L);
|
jbe@167
|
482 lua_pushliteral(L, "Illegal UTF-16 surrogate in JSON string escape sequence");
|
jbe@167
|
483 return 2;
|
jbe@167
|
484 }
|
jbe@167
|
485 }
|
jbe@167
|
486 // encode as UTF-8:
|
jbe@167
|
487 if (codepoint < 0x80) {
|
jbe@167
|
488 cbuf[outlen++] = (char)codepoint;
|
jbe@167
|
489 } else if (codepoint < 0x800) {
|
jbe@167
|
490 cbuf[outlen++] = (char)(0xc0 | (codepoint >> 6));
|
jbe@167
|
491 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
|
jbe@167
|
492 } else if (codepoint < 0x10000) {
|
jbe@167
|
493 cbuf[outlen++] = (char)(0xe0 | (codepoint >> 12));
|
jbe@167
|
494 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 6) & 0x3f));
|
jbe@167
|
495 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
|
jbe@167
|
496 } else {
|
jbe@167
|
497 cbuf[outlen++] = (char)(0xf0 | (codepoint >> 18));
|
jbe@167
|
498 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 12) & 0x3f));
|
jbe@167
|
499 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 6) & 0x3f));
|
jbe@167
|
500 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
|
jbe@167
|
501 }
|
jbe@167
|
502 break;
|
jbe@161
|
503 // unexpected escape sequence:
|
jbe@161
|
504 default:
|
jbe@167
|
505 json_import_unexpected_escape:
|
jbe@161
|
506 lua_pushnil(L);
|
jbe@161
|
507 lua_pushliteral(L, "Unexpected string escape sequence in JSON document");
|
jbe@161
|
508 return 2;
|
jbe@161
|
509 }
|
jbe@161
|
510 } else {
|
jbe@161
|
511 // normal character:
|
jbe@162
|
512 cbuf[outlen++] = c;
|
jbe@121
|
513 }
|
jbe@121
|
514 }
|
jbe@161
|
515 // process buffer to Lua string:
|
jbe@162
|
516 luaL_pushresultsize(&luabuf, outlen);
|
jbe@161
|
517 } else {
|
jbe@161
|
518 // if JSON string is empty,
|
jbe@161
|
519 // push empty Lua string:
|
jbe@161
|
520 lua_pushliteral(L, "");
|
jbe@167
|
521 // consume closing quote:
|
jbe@167
|
522 pos++;
|
jbe@121
|
523 }
|
jbe@136
|
524 // continue with processing of decoded string:
|
jbe@121
|
525 goto json_import_process_value;
|
jbe@121
|
526 }
|
jbe@136
|
527 // process values whose type is is not deducible from a single character:
|
jbe@136
|
528 if ((c >= '0' && c <= '9') || c == '-' || c == '+') {
|
jbe@146
|
529 // for numbers,
|
jbe@146
|
530 // use strtod() call to parse a (double precision) floating point number:
|
jbe@167
|
531 double numval;
|
jbe@122
|
532 char *endptr;
|
jbe@122
|
533 numval = strtod(str+pos, &endptr);
|
jbe@146
|
534 // catch parsing errors:
|
jbe@122
|
535 if (endptr == str+pos) goto json_import_syntax_error;
|
jbe@146
|
536 // consume characters that were parsed:
|
jbe@122
|
537 pos += endptr - (str+pos);
|
jbe@146
|
538 // push parsed (double precision) floating point number on Lua stack:
|
jbe@122
|
539 lua_pushnumber(L, numval);
|
jbe@122
|
540 } else if (!strncmp(str+pos, "true", 4)) {
|
jbe@136
|
541 // consume 4 input characters for "true":
|
jbe@121
|
542 pos += 4;
|
jbe@147
|
543 // put Lua true value onto stack:
|
jbe@136
|
544 lua_pushboolean(L, 1);
|
jbe@121
|
545 } else if (!strncmp(str+pos, "false", 5)) {
|
jbe@136
|
546 // consume 5 input characters for "false":
|
jbe@121
|
547 pos += 5;
|
jbe@147
|
548 // put Lua false value onto stack:
|
jbe@136
|
549 lua_pushboolean(L, 0);
|
jbe@121
|
550 } else if (!strncmp(str+pos, "null", 4)) {
|
jbe@136
|
551 // consume 4 input characters for "null":
|
jbe@136
|
552 pos += 4;
|
jbe@153
|
553 // different behavor for top-level and sub-levels:
|
jbe@153
|
554 if (level) {
|
jbe@153
|
555 // if sub-level,
|
jbe@153
|
556 // push special null-marker onto stack:
|
jbe@155
|
557 json_pushnullmark(L);
|
jbe@153
|
558 } else {
|
jbe@153
|
559 // if top-level,
|
jbe@153
|
560 // push nil onto stack:
|
jbe@153
|
561 lua_pushnil(L);
|
jbe@153
|
562 }
|
jbe@121
|
563 } else {
|
jbe@136
|
564 // all other cases are a syntax error:
|
jbe@121
|
565 goto json_import_syntax_error;
|
jbe@121
|
566 }
|
jbe@136
|
567 // process a decoded value or key value pair (expected on top of Lua stack):
|
jbe@136
|
568 json_import_process_value:
|
jbe@121
|
569 switch (mode) {
|
jbe@136
|
570 // an object key has been read:
|
jbe@124
|
571 case JSON_STATE_OBJECT_KEY:
|
jbe@136
|
572 // if an object key is not a string, then this is a syntax error:
|
jbe@121
|
573 if (lua_type(L, -1) != LUA_TSTRING) goto json_import_syntax_error;
|
jbe@146
|
574 // expect key terminator to follow:
|
jbe@124
|
575 mode = JSON_STATE_OBJECT_KEY_TERMINATOR;
|
jbe@146
|
576 // continue with loop:
|
jbe@121
|
577 goto json_import_loop;
|
jbe@136
|
578 // a key value pair has been read:
|
jbe@124
|
579 case JSON_STATE_OBJECT_VALUE:
|
jbe@136
|
580 // store key value pair in outer shadow table:
|
jbe@130
|
581 lua_rawset(L, -3);
|
jbe@146
|
582 // expect value terminator (or end of object) to follow:
|
jbe@124
|
583 mode = JSON_STATE_OBJECT_SEPARATOR;
|
jbe@146
|
584 // continue with loop:
|
jbe@121
|
585 goto json_import_loop;
|
jbe@136
|
586 // an array value has been read:
|
jbe@124
|
587 case JSON_STATE_ARRAY_VALUE:
|
jbe@152
|
588 // get current array length:
|
jbe@152
|
589 arraylen = lua_rawlen(L, -3);
|
jbe@152
|
590 // throw error if array would exceed INT_MAX elements:
|
jbe@152
|
591 // TODO: Lua 5.3 may support more elements
|
jbe@152
|
592 if (arraylen >= INT_MAX) {
|
jbe@152
|
593 lua_pushnil(L);
|
jbe@152
|
594 lua_pushfstring(L, "Array exceeded length of %d elements", INT_MAX);
|
jbe@152
|
595 }
|
jbe@136
|
596 // store value in outer shadow table:
|
jbe@152
|
597 lua_rawseti(L, -3, arraylen + 1);
|
jbe@146
|
598 // expect value terminator (or end of object) to follow:
|
jbe@124
|
599 mode = JSON_STATE_ARRAY_SEPARATOR;
|
jbe@146
|
600 // continue with loop
|
jbe@121
|
601 goto json_import_loop;
|
jbe@136
|
602 // a single value has been read:
|
jbe@124
|
603 case JSON_STATE_VALUE:
|
jbe@136
|
604 // leave value on top of stack, expect end of JSON document, and continue with loop:
|
jbe@124
|
605 mode = JSON_STATE_END;
|
jbe@121
|
606 goto json_import_loop;
|
jbe@121
|
607 }
|
jbe@146
|
608 // syntax error handling (reachable by goto statement):
|
jbe@136
|
609 json_import_syntax_error:
|
jbe@121
|
610 lua_pushnil(L);
|
jbe@121
|
611 lua_pushliteral(L, "Syntax error in JSON document");
|
jbe@121
|
612 return 2;
|
jbe@121
|
613 }
|
jbe@121
|
614
|
jbe@146
|
615 // special Lua stack indicies for json_path function:
|
jbe@138
|
616 #define json_path_shadowtbl_idx 1
|
jbe@146
|
617
|
jbe@146
|
618 // stack offset of arguments to json_path function:
|
jbe@155
|
619 #define json_path_idxshift 1
|
jbe@138
|
620
|
jbe@146
|
621 // gets a value or its type from a JSON document (passed as first argument)
|
jbe@175
|
622 // using a path (passed as variable number of keys after the first argument):
|
jbe@137
|
623 static int json_path(lua_State *L, int type_mode) {
|
jbe@146
|
624 int stacktop; // stack index of top of stack (after shifting)
|
jbe@146
|
625 int idx = 2 + json_path_idxshift; // stack index of current argument to process
|
jbe@173
|
626 // require at least one argument:
|
jbe@173
|
627 luaL_checkany(L, 1);
|
jbe@148
|
628 // insert shadowtbl into stack at position 1 (shifting the arguments):
|
jbe@144
|
629 json_regfetch(L, shadowtbl);
|
jbe@138
|
630 lua_insert(L, 1);
|
jbe@146
|
631 // store stack index of top of stack:
|
jbe@138
|
632 stacktop = lua_gettop(L);
|
jbe@146
|
633 // use first argument as "current value" (stored on top of stack):
|
jbe@138
|
634 lua_pushvalue(L, 1 + json_path_idxshift);
|
jbe@146
|
635 // process each "path key" (2nd argument and following arguments):
|
jbe@138
|
636 while (idx <= stacktop) {
|
jbe@146
|
637 // if "current value" (on top of stack) is nil, then the path cannot be walked and nil is returned:
|
jbe@137
|
638 if (lua_isnil(L, -1)) return 1;
|
jbe@137
|
639 // try to get shadow table of "current value":
|
jbe@130
|
640 lua_pushvalue(L, -1);
|
jbe@138
|
641 lua_rawget(L, json_path_shadowtbl_idx);
|
jbe@126
|
642 if (lua_isnil(L, -1)) {
|
jbe@137
|
643 // if no shadow table is found,
|
jbe@130
|
644 if (lua_type(L, -1) == LUA_TTABLE) {
|
jbe@146
|
645 // and if "current value" is a table,
|
jbe@146
|
646 // drop 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@173
|
719 #define json_set_shadowtbl_idx 1
|
jbe@173
|
720 #define json_set_objectmt_idx 2
|
jbe@173
|
721 #define json_set_arraymt_idx 3
|
jbe@173
|
722
|
jbe@173
|
723 // stack offset of arguments to json_set function:
|
jbe@173
|
724 #define json_set_idxshift 3
|
jbe@173
|
725
|
jbe@173
|
726 // sets a value (passed as second argument) in a JSON document (passed as first argument)
|
jbe@175
|
727 // using a path (passed as variable number of keys starting at third argument):
|
jbe@173
|
728 static int json_set(lua_State *L) {
|
jbe@173
|
729 int stacktop; // stack index of top of stack (after shifting)
|
jbe@173
|
730 int idx = 3; // stack index of current argument to process
|
jbe@173
|
731 // require at least two arguments:
|
jbe@173
|
732 luaL_checkany(L, 1);
|
jbe@173
|
733 luaL_checkany(L, 2);
|
jbe@173
|
734 // insert shadowtbl into stack at position 1 (shifting the arguments):
|
jbe@173
|
735 json_regfetch(L, shadowtbl);
|
jbe@173
|
736 lua_insert(L, 1);
|
jbe@173
|
737 // insert objectmt into stack at position 2 (shifting the arguments):
|
jbe@173
|
738 json_regfetch(L, objectmt);
|
jbe@173
|
739 lua_insert(L, 2);
|
jbe@173
|
740 // insert arraymt into stack at position 3 (shifting the arguments):
|
jbe@173
|
741 json_regfetch(L, arraymt);
|
jbe@173
|
742 lua_insert(L, 3);
|
jbe@173
|
743 // store stack index of top of stack:
|
jbe@173
|
744 stacktop = lua_gettop(L);
|
jbe@173
|
745 // use nil as initial "parent value":
|
jbe@173
|
746 lua_pushnil(L);
|
jbe@173
|
747 // use first argument as "current value":
|
jbe@173
|
748 lua_pushvalue(L, 1 + json_set_idxshift);
|
jbe@173
|
749 // set all necessary values in path:
|
jbe@173
|
750 for (idx = 3 + json_set_idxshift; idx<=stacktop; idx++) {
|
jbe@173
|
751 // push metatable of "current value" onto stack:
|
jbe@173
|
752 if (!lua_getmetatable(L, -1)) lua_pushnil(L);
|
jbe@173
|
753 // distinguish according to type of path key:
|
jbe@173
|
754 switch (lua_type(L, idx)) {
|
jbe@173
|
755 case LUA_TSTRING:
|
jbe@173
|
756 // if path key is a string,
|
jbe@173
|
757 // check if "current value" is a JSON object (or table without metatable):
|
jbe@173
|
758 if (
|
jbe@173
|
759 lua_rawequal(L, -1, json_set_objectmt_idx) ||
|
jbe@173
|
760 (lua_isnil(L, -1) && lua_type(L, -2) == LUA_TTABLE)
|
jbe@173
|
761 ) {
|
jbe@173
|
762 // if "current value" is acceptable,
|
jbe@173
|
763 // pop metatable and leave "current value" on top of stack:
|
jbe@173
|
764 lua_pop(L, 1);
|
jbe@173
|
765 } else {
|
jbe@173
|
766 // if "current value" is not acceptable:
|
jbe@173
|
767 // pop metatable and "current value":
|
jbe@173
|
768 lua_pop(L, 2);
|
jbe@173
|
769 // throw error if parent element does not exist:
|
jbe@173
|
770 if (lua_isnil(L, -1)) return luaL_error(L, "Root element is not a JSON object");
|
jbe@173
|
771 // push new JSON object as "current value" onto stack:
|
jbe@173
|
772 lua_newtable(L);
|
jbe@173
|
773 // create and register shadow table:
|
jbe@173
|
774 lua_pushvalue(L, -1);
|
jbe@173
|
775 lua_newtable(L);
|
jbe@173
|
776 lua_rawset(L, json_set_shadowtbl_idx);
|
jbe@173
|
777 // set metatable of JSON object:
|
jbe@173
|
778 lua_pushvalue(L, json_set_objectmt_idx);
|
jbe@173
|
779 lua_setmetatable(L, -2);
|
jbe@173
|
780 // set entry in "parent value":
|
jbe@173
|
781 lua_pushvalue(L, idx-1);
|
jbe@173
|
782 lua_pushvalue(L, -2);
|
jbe@173
|
783 lua_settable(L, -4);
|
jbe@173
|
784 }
|
jbe@173
|
785 break;
|
jbe@173
|
786 case LUA_TNUMBER:
|
jbe@173
|
787 // if path key is a number,
|
jbe@173
|
788 // check if "current value" is a JSON array (or table without metatable):
|
jbe@173
|
789 if (
|
jbe@173
|
790 lua_rawequal(L, -1, json_set_arraymt_idx) ||
|
jbe@173
|
791 (lua_isnil(L, -1) && lua_type(L, -2) == LUA_TTABLE)
|
jbe@173
|
792 ) {
|
jbe@173
|
793 // if "current value" is acceptable,
|
jbe@173
|
794 // pop metatable and leave "current value" on top of stack:
|
jbe@173
|
795 lua_pop(L, 1);
|
jbe@173
|
796 } else {
|
jbe@173
|
797 // if "current value" is not acceptable:
|
jbe@173
|
798 // pop metatable and "current value":
|
jbe@173
|
799 lua_pop(L, 2);
|
jbe@173
|
800 // throw error if parent element does not exist:
|
jbe@173
|
801 if (lua_isnil(L, -1)) return luaL_error(L, "Root element is not a JSON array");
|
jbe@173
|
802 // push new JSON array as "current value" onto stack:
|
jbe@173
|
803 lua_newtable(L);
|
jbe@173
|
804 // create and register shadow table:
|
jbe@173
|
805 lua_pushvalue(L, -1);
|
jbe@173
|
806 lua_newtable(L);
|
jbe@173
|
807 lua_rawset(L, json_set_shadowtbl_idx);
|
jbe@173
|
808 // set metatable of JSON array:
|
jbe@173
|
809 lua_pushvalue(L, json_set_arraymt_idx);
|
jbe@173
|
810 lua_setmetatable(L, -2);
|
jbe@173
|
811 // set entry in "parent value":
|
jbe@173
|
812 lua_pushvalue(L, idx-1);
|
jbe@173
|
813 lua_pushvalue(L, -2);
|
jbe@173
|
814 lua_settable(L, -4);
|
jbe@173
|
815 }
|
jbe@173
|
816 break;
|
jbe@173
|
817 default:
|
jbe@173
|
818 return luaL_error(L, "Invalid path key of type %s", lua_typename(L, lua_type(L, idx)));
|
jbe@173
|
819 }
|
jbe@173
|
820 // check if last path element is being processed:
|
jbe@173
|
821 if (idx == stacktop) {
|
jbe@173
|
822 // if the last path element is being processed,
|
jbe@173
|
823 // set last path value in "current value" container:
|
jbe@173
|
824 lua_pushvalue(L, idx);
|
jbe@173
|
825 lua_pushvalue(L, 2 + json_set_idxshift);
|
jbe@173
|
826 lua_settable(L, -3);
|
jbe@173
|
827 } else {
|
jbe@173
|
828 // if the processed path element is not the last,
|
jbe@173
|
829 // use old "current value" as new "parent value"
|
jbe@173
|
830 lua_remove(L, -2);
|
jbe@173
|
831 // push new "current value" onto stack by performing a lookup:
|
jbe@173
|
832 lua_pushvalue(L, idx);
|
jbe@173
|
833 lua_gettable(L, -2);
|
jbe@173
|
834 }
|
jbe@173
|
835 }
|
jbe@173
|
836 // return first argument for convenience:
|
jbe@173
|
837 lua_settop(L, 1 + json_set_idxshift);
|
jbe@173
|
838 return 1;
|
jbe@173
|
839 }
|
jbe@173
|
840
|
jbe@147
|
841 // returns the length of a JSON array (or zero for a table without numeric keys):
|
jbe@130
|
842 static int json_len(lua_State *L) {
|
jbe@147
|
843 // stack shall contain one function argument:
|
jbe@130
|
844 lua_settop(L, 1);
|
jbe@148
|
845 // try to get corresponding shadow table for first argument:
|
jbe@144
|
846 json_regfetch(L, shadowtbl);
|
jbe@130
|
847 lua_pushvalue(L, 1);
|
jbe@138
|
848 lua_rawget(L, -2);
|
jbe@147
|
849 // if shadow table does not exist, return length of argument, else length of shadow table:
|
jbe@147
|
850 lua_pushnumber(L, lua_rawlen(L, lua_isnil(L, -1) ? 1 : -1));
|
jbe@123
|
851 return 1;
|
jbe@123
|
852 }
|
jbe@123
|
853
|
jbe@175
|
854 // __index metamethod for JSON objects and JSON arrays:
|
jbe@130
|
855 static int json_index(lua_State *L) {
|
jbe@148
|
856 // stack shall contain two function arguments:
|
jbe@130
|
857 lua_settop(L, 2);
|
jbe@155
|
858 // get corresponding shadow table for first argument:
|
jbe@144
|
859 json_regfetch(L, shadowtbl);
|
jbe@130
|
860 lua_pushvalue(L, 1);
|
jbe@155
|
861 lua_rawget(L, -2);
|
jbe@148
|
862 // throw error if no shadow table was found:
|
jbe@139
|
863 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@148
|
864 // use key passed as second argument to lookup value in shadow table:
|
jbe@130
|
865 lua_pushvalue(L, 2);
|
jbe@130
|
866 lua_rawget(L, -2);
|
jbe@148
|
867 // if value is null-marker, then push nil onto stack:
|
jbe@155
|
868 if (json_isnullmark(L, -1)) lua_pushnil(L);
|
jbe@148
|
869 // return either looked up value, or nil
|
jbe@127
|
870 return 1;
|
jbe@127
|
871 }
|
jbe@127
|
872
|
jbe@175
|
873 // __newindex metamethod for JSON objects and JSON arrays:
|
jbe@130
|
874 static int json_newindex(lua_State *L) {
|
jbe@148
|
875 // stack shall contain three function arguments:
|
jbe@130
|
876 lua_settop(L, 3);
|
jbe@148
|
877 // get corresponding shadow table for first argument:
|
jbe@144
|
878 json_regfetch(L, shadowtbl);
|
jbe@123
|
879 lua_pushvalue(L, 1);
|
jbe@143
|
880 lua_rawget(L, -2);
|
jbe@148
|
881 // throw error if no shadow table was found:
|
jbe@130
|
882 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@148
|
883 // replace first argument with shadow table:
|
jbe@130
|
884 lua_replace(L, 1);
|
jbe@148
|
885 // reset stack and use second and third argument to write to shadow table:
|
jbe@139
|
886 lua_settop(L, 3);
|
jbe@130
|
887 lua_rawset(L, 1);
|
jbe@148
|
888 // return nothing:
|
jbe@148
|
889 return 0;
|
jbe@121
|
890 }
|
jbe@121
|
891
|
jbe@175
|
892 // function returned as first value by json_pairs function:
|
jbe@135
|
893 static int json_pairs_iterfunc(lua_State *L) {
|
jbe@149
|
894 // stack shall contain two function arguments:
|
jbe@135
|
895 lua_settop(L, 2);
|
jbe@155
|
896 // get corresponding shadow table for first argument:
|
jbe@144
|
897 json_regfetch(L, shadowtbl);
|
jbe@135
|
898 lua_pushvalue(L, 1);
|
jbe@155
|
899 lua_rawget(L, -2);
|
jbe@149
|
900 // throw error if no shadow table was found:
|
jbe@135
|
901 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@149
|
902 // get next key value pair from shadow table (using previous key from argument 2)
|
jbe@149
|
903 // and return nothing if there is no next pair:
|
jbe@135
|
904 lua_pushvalue(L, 2);
|
jbe@135
|
905 if (!lua_next(L, -2)) return 0;
|
jbe@149
|
906 // replace null-marker with nil:
|
jbe@155
|
907 if (json_isnullmark(L, -1)) {
|
jbe@135
|
908 lua_pop(L, 1);
|
jbe@135
|
909 lua_pushnil(L);
|
jbe@135
|
910 }
|
jbe@149
|
911 // return key and value (or key and nil, if null-marker was found):
|
jbe@135
|
912 return 2;
|
jbe@135
|
913 }
|
jbe@135
|
914
|
jbe@149
|
915 // returns a triple such that 'for key, value in pairs(obj) do ... end'
|
jbe@175
|
916 // iterates through all key value pairs (including JSON null values represented as Lua nil):
|
jbe@135
|
917 static int json_pairs(lua_State *L) {
|
jbe@172
|
918 // require one argument to function
|
jbe@172
|
919 luaL_checkany(L, 1);
|
jbe@149
|
920 // return triple of function json_pairs_iterfunc, first argument, and nil:
|
jbe@139
|
921 lua_pushcfunction(L, json_pairs_iterfunc);
|
jbe@135
|
922 lua_pushvalue(L, 1);
|
jbe@135
|
923 lua_pushnil(L);
|
jbe@135
|
924 return 3;
|
jbe@135
|
925 }
|
jbe@135
|
926
|
jbe@175
|
927 // function returned as first value by json_ipairs function:
|
jbe@134
|
928 static int json_ipairs_iterfunc(lua_State *L) {
|
jbe@152
|
929 lua_Integer idx;
|
jbe@149
|
930 // stack shall contain two function arguments:
|
jbe@134
|
931 lua_settop(L, 2);
|
jbe@149
|
932 // calculate new index by incrementing second argument:
|
jbe@134
|
933 idx = lua_tointeger(L, 2) + 1;
|
jbe@149
|
934 // get corresponding shadow table for first argument:
|
jbe@155
|
935 json_regfetch(L, shadowtbl);
|
jbe@134
|
936 lua_pushvalue(L, 1);
|
jbe@155
|
937 lua_rawget(L, -2);
|
jbe@149
|
938 // throw error if no shadow table was found:
|
jbe@134
|
939 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@149
|
940 // do integer lookup in shadow table:
|
jbe@134
|
941 lua_rawgeti(L, -1, idx);
|
jbe@149
|
942 // return nothing if there was no value:
|
jbe@134
|
943 if (lua_isnil(L, -1)) return 0;
|
jbe@149
|
944 // return new index and
|
jbe@149
|
945 // either the looked up value if it is not equal to the null-marker
|
jbe@149
|
946 // or nil instead of null-marker:
|
jbe@134
|
947 lua_pushinteger(L, idx);
|
jbe@155
|
948 if (json_isnullmark(L, -2)) lua_pushnil(L);
|
jbe@134
|
949 else lua_pushvalue(L, -2);
|
jbe@134
|
950 return 2;
|
jbe@134
|
951 }
|
jbe@134
|
952
|
jbe@149
|
953 // returns a triple such that 'for idx, value in ipairs(ary) do ... end'
|
jbe@175
|
954 // iterates through all values (including JSON null values represented as Lua nil):
|
jbe@134
|
955 static int json_ipairs(lua_State *L) {
|
jbe@172
|
956 // require one argument to function
|
jbe@172
|
957 luaL_checkany(L, 1);
|
jbe@149
|
958 // return triple of function json_ipairs_iterfunc, first argument, and zero:
|
jbe@139
|
959 lua_pushcfunction(L, json_ipairs_iterfunc);
|
jbe@134
|
960 lua_pushvalue(L, 1);
|
jbe@134
|
961 lua_pushinteger(L, 0);
|
jbe@134
|
962 return 3;
|
jbe@134
|
963 }
|
jbe@134
|
964
|
jbe@175
|
965 // datatype representing a table key:
|
jbe@175
|
966 // (used for sorting)
|
jbe@163
|
967 typedef struct {
|
jbe@163
|
968 size_t length;
|
jbe@163
|
969 const char *data;
|
jbe@163
|
970 } json_key_t;
|
jbe@163
|
971
|
jbe@175
|
972 // comparation function for table keys to be passed to qsort function:
|
jbe@163
|
973 static int json_key_cmp(json_key_t *key1, json_key_t *key2) {
|
jbe@163
|
974 size_t pos = 0;
|
jbe@163
|
975 unsigned char c1, c2;
|
jbe@163
|
976 while (1) {
|
jbe@163
|
977 if (key1->length > pos) {
|
jbe@163
|
978 if (key2->length > pos) {
|
jbe@163
|
979 c1 = key1->data[pos];
|
jbe@163
|
980 c2 = key2->data[pos];
|
jbe@163
|
981 if (c1 < c2) return -1;
|
jbe@163
|
982 else if (c1 > c2) return 1;
|
jbe@163
|
983 } else {
|
jbe@163
|
984 return 1;
|
jbe@163
|
985 }
|
jbe@163
|
986 } else {
|
jbe@163
|
987 if (key2->length > pos) {
|
jbe@163
|
988 return -1;
|
jbe@163
|
989 } else {
|
jbe@163
|
990 return 0;
|
jbe@163
|
991 }
|
jbe@163
|
992 }
|
jbe@163
|
993 pos++;
|
jbe@163
|
994 }
|
jbe@163
|
995 }
|
jbe@163
|
996
|
jbe@175
|
997 // constants for type detection of ambiguous tables:
|
jbe@154
|
998 #define JSON_TABLETYPE_UNKNOWN 0
|
jbe@154
|
999 #define JSON_TABLETYPE_OBJECT 1
|
jbe@154
|
1000 #define JSON_TABLETYPE_ARRAY 2
|
jbe@154
|
1001
|
jbe@175
|
1002 // special Lua stack indicies for json_export_internal function:
|
jbe@164
|
1003 #define json_export_internal_indentstring_idx 1
|
jbe@164
|
1004 #define json_export_internal_level_idx 2
|
jbe@164
|
1005 #define json_export_internal_value_idx 3
|
jbe@164
|
1006 #define json_export_internal_tmp_idx 4
|
jbe@164
|
1007
|
jbe@175
|
1008 // encodes a JSON document (passed as third argument)
|
jbe@175
|
1009 // optionally using indentation (indentation string passed as first argument)
|
jbe@175
|
1010 // for a certain depth level (passed as second argument):
|
jbe@164
|
1011 static int json_export_internal(lua_State *L) {
|
jbe@175
|
1012 int level; // current depth level
|
jbe@175
|
1013 int pretty; // pretty printing on? (i.e. printing with indentation)
|
jbe@175
|
1014 int i; // iteration variable for level dependent repetitions:
|
jbe@175
|
1015 lua_Number num; // number to encode
|
jbe@175
|
1016 const char *str; // string to encode
|
jbe@175
|
1017 size_t strlen; // length of string to encode
|
jbe@175
|
1018 unsigned char c; // character to encode (unsigned!)
|
jbe@175
|
1019 size_t pos = 0; // position in string or position of current key (initialized with zero!)
|
jbe@175
|
1020 luaL_Buffer buf; // Lua buffer to create strings
|
jbe@175
|
1021 char hexcode[7]; // store for unicode hex escape sequence
|
jbe@175
|
1022 // NOTE: 7 bytes due to backslash, character 'u', 4 hex digits, and terminating NULL byte
|
jbe@175
|
1023 int tabletype = JSON_TABLETYPE_UNKNOWN; // table type: unknown, JSON object, or JSON array
|
jbe@175
|
1024 int anyelement = 0; // set to 1 if at least one array element has been processed
|
jbe@175
|
1025 size_t keycount = 0; // number of string keys in object
|
jbe@175
|
1026 json_key_t *keybuf = NULL; // temporary buffer to store (and sort) string keys of objects
|
jbe@175
|
1027 lua_Integer arrayidx; // index to iterate through arrays
|
jbe@175
|
1028 // stack shall contain three function arguments:
|
jbe@164
|
1029 lua_settop(L, json_export_internal_value_idx);
|
jbe@175
|
1030 // if value to encode is the null-marker, then treat it the same as nil:
|
jbe@164
|
1031 if (json_isnullmark(L, json_export_internal_value_idx)) {
|
jbe@164
|
1032 lua_pop(L, 1);
|
jbe@157
|
1033 lua_pushnil(L);
|
jbe@157
|
1034 }
|
jbe@175
|
1035 // distinguish between different Lua types:
|
jbe@164
|
1036 switch (lua_type(L, json_export_internal_value_idx)) {
|
jbe@175
|
1037 // value to encode is nil:
|
jbe@154
|
1038 case LUA_TNIL:
|
jbe@175
|
1039 // return string "null":
|
jbe@154
|
1040 lua_pushliteral(L, "null");
|
jbe@154
|
1041 return 1;
|
jbe@175
|
1042 // value to encode is of type number:
|
jbe@154
|
1043 case LUA_TNUMBER:
|
jbe@175
|
1044 // convert value to double precision number:
|
jbe@164
|
1045 num = lua_tonumber(L, json_export_internal_value_idx);
|
jbe@175
|
1046 // throw error if number is not-a-number:
|
jbe@154
|
1047 if (isnan(num)) return luaL_error(L, "JSON export not possible for NaN value");
|
jbe@175
|
1048 // throw error if number is positive or negative infinity:
|
jbe@154
|
1049 if (isinf(num)) return luaL_error(L, "JSON export not possible for infinite numbers");
|
jbe@175
|
1050 // return Lua's string encoding of the number:
|
jbe@164
|
1051 lua_tostring(L, json_export_internal_value_idx);
|
jbe@154
|
1052 return 1;
|
jbe@175
|
1053 // value to encode is of type boolean:
|
jbe@154
|
1054 case LUA_TBOOLEAN:
|
jbe@175
|
1055 // return string "true" or "false" according to boolean value:
|
jbe@164
|
1056 if (lua_toboolean(L, json_export_internal_value_idx)) {
|
jbe@164
|
1057 lua_pushliteral(L, "true");
|
jbe@164
|
1058 } else {
|
jbe@164
|
1059 lua_pushliteral(L, "false");
|
jbe@164
|
1060 }
|
jbe@154
|
1061 return 1;
|
jbe@175
|
1062 // value to encode is of type string:
|
jbe@154
|
1063 case LUA_TSTRING:
|
jbe@175
|
1064 // quote, escape and return string:
|
jbe@164
|
1065 str = lua_tolstring(L, 3, &strlen);
|
jbe@154
|
1066 luaL_buffinit(L, &buf);
|
jbe@154
|
1067 luaL_addchar(&buf, '"');
|
jbe@154
|
1068 while (pos < strlen) {
|
jbe@154
|
1069 c = str[pos++];
|
jbe@154
|
1070 if (c == '"') luaL_addstring(&buf, "\\\"");
|
jbe@154
|
1071 else if (c == '\\') luaL_addstring(&buf, "\\\\");
|
jbe@154
|
1072 else if (c == 127) luaL_addstring(&buf, "\\u007F");
|
jbe@154
|
1073 else if (c >= 32) luaL_addchar(&buf, c);
|
jbe@154
|
1074 else if (c == '\b') luaL_addstring(&buf, "\\b");
|
jbe@154
|
1075 else if (c == '\f') luaL_addstring(&buf, "\\f");
|
jbe@154
|
1076 else if (c == '\n') luaL_addstring(&buf, "\\n");
|
jbe@154
|
1077 else if (c == '\r') luaL_addstring(&buf, "\\r");
|
jbe@154
|
1078 else if (c == '\t') luaL_addstring(&buf, "\\t");
|
jbe@154
|
1079 else if (c == '\v') luaL_addstring(&buf, "\\v");
|
jbe@154
|
1080 else {
|
jbe@154
|
1081 sprintf(hexcode, "\\u%04X", c);
|
jbe@154
|
1082 luaL_addstring(&buf, hexcode);
|
jbe@154
|
1083 }
|
jbe@154
|
1084 }
|
jbe@154
|
1085 luaL_addchar(&buf, '"');
|
jbe@154
|
1086 luaL_pushresult(&buf);
|
jbe@154
|
1087 return 1;
|
jbe@175
|
1088 // value to encode is of type table (this includes JSON objects and JSON arrays):
|
jbe@154
|
1089 case LUA_TTABLE:
|
jbe@175
|
1090 // use table's metatable to try to determine type of table:
|
jbe@164
|
1091 if (lua_getmetatable(L, json_export_internal_value_idx)) {
|
jbe@154
|
1092 json_regfetch(L, objectmt);
|
jbe@154
|
1093 if (lua_rawequal(L, -2, -1)) {
|
jbe@154
|
1094 tabletype = JSON_TABLETYPE_OBJECT;
|
jbe@154
|
1095 } else {
|
jbe@154
|
1096 json_regfetch(L, arraymt);
|
jbe@164
|
1097 if (lua_rawequal(L, -3, -1)) {
|
jbe@164
|
1098 tabletype = JSON_TABLETYPE_ARRAY;
|
jbe@164
|
1099 } else {
|
jbe@164
|
1100 return luaL_error(L, "JSON export not possible for tables with nonsupported metatable");
|
jbe@164
|
1101 }
|
jbe@154
|
1102 }
|
jbe@154
|
1103 }
|
jbe@175
|
1104 // replace table with its shadow table if existent, and reset stack:
|
jbe@154
|
1105 json_regfetch(L, shadowtbl);
|
jbe@164
|
1106 lua_pushvalue(L, json_export_internal_value_idx);
|
jbe@154
|
1107 lua_rawget(L, -2);
|
jbe@164
|
1108 if (!lua_isnil(L, -1)) lua_replace(L, json_export_internal_value_idx);
|
jbe@164
|
1109 lua_settop(L, json_export_internal_value_idx);
|
jbe@175
|
1110 // check if type of table is still undetermined:
|
jbe@154
|
1111 if (tabletype == JSON_TABLETYPE_UNKNOWN) {
|
jbe@175
|
1112 // if yes, iterate over all keys:
|
jbe@164
|
1113 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
|
jbe@164
|
1114 switch (lua_type(L, -2)) {
|
jbe@164
|
1115 case LUA_TSTRING:
|
jbe@175
|
1116 // for string keys,
|
jbe@175
|
1117 // increase keycount (may avoid another iteration):
|
jbe@164
|
1118 keycount++;
|
jbe@175
|
1119 // if type of table was unknown, then type of table is a JSON object now:
|
jbe@164
|
1120 if (tabletype == JSON_TABLETYPE_UNKNOWN) tabletype = JSON_TABLETYPE_OBJECT;
|
jbe@175
|
1121 // if type of table was a JSON array, then the type of table is ambiguous now
|
jbe@175
|
1122 // and an error is thrown:
|
jbe@164
|
1123 else if (tabletype == JSON_TABLETYPE_ARRAY) goto json_export_tabletype_error;
|
jbe@164
|
1124 break;
|
jbe@164
|
1125 case LUA_TNUMBER:
|
jbe@175
|
1126 // for numeric keys,
|
jbe@175
|
1127 // if type of table was unknown, then type of table is a JSON array now:
|
jbe@164
|
1128 if (tabletype == JSON_TABLETYPE_UNKNOWN) tabletype = JSON_TABLETYPE_ARRAY;
|
jbe@175
|
1129 // if type of table was a JSON object, then the type of table is ambiguous now
|
jbe@175
|
1130 // and an error is thrown:
|
jbe@164
|
1131 else if (tabletype == JSON_TABLETYPE_OBJECT) goto json_export_tabletype_error;
|
jbe@164
|
1132 break;
|
jbe@154
|
1133 }
|
jbe@154
|
1134 }
|
jbe@154
|
1135 }
|
jbe@175
|
1136 // set pretty variable to 1 if pretty printing (with indentation) is desired:
|
jbe@164
|
1137 pretty = lua_toboolean(L, json_export_internal_indentstring_idx);
|
jbe@175
|
1138 // set level variable to corresponding function argument increased by one:
|
jbe@164
|
1139 level = lua_tointeger(L, json_export_internal_level_idx) + 1;
|
jbe@175
|
1140 // throw error if there are more levels that could be imported by this library:
|
jbe@164
|
1141 if (level > JSON_MAXDEPTH) {
|
jbe@164
|
1142 return luaL_error(L, "More than %d nested JSON levels", JSON_MAXDEPTH);
|
jbe@164
|
1143 }
|
jbe@175
|
1144 // distinguish between JSON objects and JSON arrays:
|
jbe@154
|
1145 switch (tabletype) {
|
jbe@175
|
1146 // JSON object:
|
jbe@154
|
1147 case JSON_TABLETYPE_OBJECT:
|
jbe@175
|
1148 // calculate count of string keys unless it has been calculated before:
|
jbe@164
|
1149 if (!keycount) {
|
jbe@164
|
1150 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
|
jbe@164
|
1151 if (lua_type(L, -2) == LUA_TSTRING) keycount++;
|
jbe@164
|
1152 }
|
jbe@163
|
1153 }
|
jbe@175
|
1154 // create a sorted list of all string keys in memory:
|
jbe@163
|
1155 if (keycount) {
|
jbe@175
|
1156 // allocate memory for string keys:
|
jbe@163
|
1157 keybuf = calloc(keycount, sizeof(json_key_t));
|
jbe@175
|
1158 // check if memory allocation was successful:
|
jbe@175
|
1159 if (!keybuf) {
|
jbe@175
|
1160 // in case of memory exhaustion, try to collect garbage:
|
jbe@175
|
1161 lua_gc(L, LUA_GCCOLLECT, 0);
|
jbe@175
|
1162 // try to allocate memory again:
|
jbe@175
|
1163 keybuf = calloc(keycount, sizeof(json_key_t));
|
jbe@175
|
1164 // throw error if memory allocation failed again:
|
jbe@175
|
1165 if (!keybuf) {
|
jbe@175
|
1166 return luaL_error(L, "Memory allocation failed in JSON library");
|
jbe@175
|
1167 }
|
jbe@175
|
1168 }
|
jbe@175
|
1169 // copy all string keys to the C array:
|
jbe@164
|
1170 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
|
jbe@163
|
1171 if (lua_type(L, -2) == LUA_TSTRING) {
|
jbe@175
|
1172 json_key_t *key = keybuf + (pos++);
|
jbe@163
|
1173 key->data = lua_tolstring(L, -2, &key->length);
|
jbe@163
|
1174 }
|
jbe@163
|
1175 }
|
jbe@175
|
1176 // sort C array using quicksort:
|
jbe@163
|
1177 qsort(keybuf, keycount, sizeof(json_key_t), (void *)json_key_cmp);
|
jbe@163
|
1178 }
|
jbe@175
|
1179 // create Lua string buffer:
|
jbe@154
|
1180 luaL_buffinit(L, &buf);
|
jbe@175
|
1181 // add opening bracket to output buffer:
|
jbe@154
|
1182 luaL_addchar(&buf, '{');
|
jbe@175
|
1183 // iterate through all (sorted) string keys:
|
jbe@175
|
1184 for (pos=0; pos<keycount; pos++) {
|
jbe@175
|
1185 json_key_t *key = keybuf + pos;
|
jbe@175
|
1186 // add comma to output buffer unless we process the first key:
|
jbe@175
|
1187 if (pos) luaL_addchar(&buf, ',');
|
jbe@175
|
1188 // handle indentation for pretty results:
|
jbe@164
|
1189 if (pretty) {
|
jbe@164
|
1190 luaL_addchar(&buf, '\n');
|
jbe@164
|
1191 for (i=0; i<level; i++) {
|
jbe@164
|
1192 lua_pushvalue(L, json_export_internal_indentstring_idx);
|
jbe@164
|
1193 luaL_addvalue(&buf);
|
jbe@164
|
1194 }
|
jbe@164
|
1195 }
|
jbe@175
|
1196 // recursive call to encode key:
|
jbe@164
|
1197 lua_pushcfunction(L, json_export_internal);
|
jbe@164
|
1198 lua_pushvalue(L, json_export_internal_indentstring_idx);
|
jbe@164
|
1199 lua_pushinteger(L, level);
|
jbe@163
|
1200 lua_pushlstring(L, key->data, key->length);
|
jbe@164
|
1201 if (lua_pcall(L, 3, 1, 0)) {
|
jbe@175
|
1202 // free memory of sorted string keys on error:
|
jbe@163
|
1203 if (keybuf) free(keybuf);
|
jbe@175
|
1204 // rethrow error:
|
jbe@163
|
1205 return lua_error(L);
|
jbe@154
|
1206 }
|
jbe@175
|
1207 // add encoded key to output buffer:
|
jbe@163
|
1208 luaL_addvalue(&buf);
|
jbe@175
|
1209 // add colon to output buffer:
|
jbe@163
|
1210 luaL_addchar(&buf, ':');
|
jbe@175
|
1211 // handle indentation for pretty results:
|
jbe@164
|
1212 if (pretty) luaL_addchar(&buf, ' ');
|
jbe@175
|
1213 // recursive call to encode value:
|
jbe@164
|
1214 lua_pushcfunction(L, json_export_internal);
|
jbe@164
|
1215 lua_pushvalue(L, json_export_internal_indentstring_idx);
|
jbe@164
|
1216 lua_pushinteger(L, level);
|
jbe@163
|
1217 lua_pushlstring(L, key->data, key->length);
|
jbe@164
|
1218 lua_rawget(L, json_export_internal_value_idx);
|
jbe@164
|
1219 if (lua_pcall(L, 3, 1, 0)) {
|
jbe@175
|
1220 // free memory of sorted string keys on error:
|
jbe@163
|
1221 if (keybuf) free(keybuf);
|
jbe@175
|
1222 // rethrow error:
|
jbe@163
|
1223 return lua_error(L);
|
jbe@163
|
1224 }
|
jbe@175
|
1225 // add encoded value to output buffer:
|
jbe@163
|
1226 luaL_addvalue(&buf);
|
jbe@154
|
1227 }
|
jbe@175
|
1228 // decrement level variable for all following statements:
|
jbe@175
|
1229 level--;
|
jbe@175
|
1230 // free memory of sorted string keys:
|
jbe@163
|
1231 if (keybuf) free(keybuf);
|
jbe@175
|
1232 // handle indentation for pretty results:
|
jbe@164
|
1233 if (pretty && keycount != 0) {
|
jbe@164
|
1234 luaL_addchar(&buf, '\n');
|
jbe@175
|
1235 for (i=0; i<level; i++) {
|
jbe@164
|
1236 lua_pushvalue(L, json_export_internal_indentstring_idx);
|
jbe@164
|
1237 luaL_addvalue(&buf);
|
jbe@164
|
1238 }
|
jbe@164
|
1239 }
|
jbe@175
|
1240 // add closing bracket to output buffer:
|
jbe@154
|
1241 luaL_addchar(&buf, '}');
|
jbe@175
|
1242 // for pretty results, add final newline character if outermost container is processed:
|
jbe@175
|
1243 if (pretty && level == 0) luaL_addchar(&buf, '\n');
|
jbe@175
|
1244 // convert and return buffer:
|
jbe@154
|
1245 luaL_pushresult(&buf);
|
jbe@154
|
1246 return 1;
|
jbe@175
|
1247 // JSON array:
|
jbe@154
|
1248 case JSON_TABLETYPE_ARRAY:
|
jbe@175
|
1249 // reserve an extra element on the stack (needed because Lua buffer has unknown size on stack):
|
jbe@164
|
1250 lua_settop(L, json_export_internal_tmp_idx);
|
jbe@175
|
1251 // create Lua string buffer:
|
jbe@154
|
1252 luaL_buffinit(L, &buf);
|
jbe@175
|
1253 // add opening bracket to output buffer:
|
jbe@154
|
1254 luaL_addchar(&buf, '[');
|
jbe@175
|
1255 // iterate through integer keys:
|
jbe@175
|
1256 for (arrayidx = 1; ; arrayidx++) {
|
jbe@175
|
1257 // get value in array, and break if nil:
|
jbe@175
|
1258 lua_rawgeti(L, json_export_internal_value_idx, arrayidx);
|
jbe@154
|
1259 if (lua_isnil(L, -1)) {
|
jbe@154
|
1260 lua_pop(L, 1);
|
jbe@154
|
1261 break;
|
jbe@154
|
1262 }
|
jbe@175
|
1263 // store value below Lua string buffer on stack (to allow operation on string buffer):
|
jbe@164
|
1264 lua_replace(L, json_export_internal_tmp_idx);
|
jbe@175
|
1265 //
|
jbe@175
|
1266 // add comma to output buffer unless we process the first element:
|
jbe@164
|
1267 if (anyelement) luaL_addchar(&buf, ',');
|
jbe@175
|
1268 // remember that we processed an element:
|
jbe@164
|
1269 anyelement = 1;
|
jbe@175
|
1270 // handle indentation for pretty results:
|
jbe@164
|
1271 if (pretty) {
|
jbe@164
|
1272 luaL_addchar(&buf, '\n');
|
jbe@164
|
1273 for (i=0; i<level; i++) {
|
jbe@164
|
1274 lua_pushvalue(L, json_export_internal_indentstring_idx);
|
jbe@164
|
1275 luaL_addvalue(&buf);
|
jbe@164
|
1276 }
|
jbe@164
|
1277 }
|
jbe@175
|
1278 // recursive call to encode previously stored value:
|
jbe@164
|
1279 lua_pushcfunction(L, json_export_internal);
|
jbe@164
|
1280 lua_pushvalue(L, json_export_internal_indentstring_idx);
|
jbe@164
|
1281 lua_pushinteger(L, level);
|
jbe@164
|
1282 lua_pushvalue(L, json_export_internal_tmp_idx);
|
jbe@164
|
1283 lua_call(L, 3, 1);
|
jbe@175
|
1284 // add encoded value to output buffer:
|
jbe@154
|
1285 luaL_addvalue(&buf);
|
jbe@154
|
1286 }
|
jbe@175
|
1287 // decrement level variable for all following statements:
|
jbe@175
|
1288 level--;
|
jbe@175
|
1289 // handle indentation for pretty results:
|
jbe@164
|
1290 if (pretty && anyelement) {
|
jbe@164
|
1291 luaL_addchar(&buf, '\n');
|
jbe@175
|
1292 for (i=0; i<level; i++) {
|
jbe@164
|
1293 lua_pushvalue(L, json_export_internal_indentstring_idx);
|
jbe@164
|
1294 luaL_addvalue(&buf);
|
jbe@164
|
1295 }
|
jbe@164
|
1296 }
|
jbe@175
|
1297 // add closing bracket to output buffer:
|
jbe@154
|
1298 luaL_addchar(&buf, ']');
|
jbe@175
|
1299 // for pretty results, add final newline character if outermost container is processed:
|
jbe@175
|
1300 if (pretty && level == 0) luaL_addchar(&buf, '\n');
|
jbe@175
|
1301 // convert and return buffer:
|
jbe@154
|
1302 luaL_pushresult(&buf);
|
jbe@154
|
1303 return 1;
|
jbe@154
|
1304 }
|
jbe@175
|
1305 // throw error if table type is unknown:
|
jbe@154
|
1306 json_export_tabletype_error:
|
jbe@154
|
1307 return luaL_error(L, "JSON export not possible for ambiguous table (cannot decide whether it is an object or array)");
|
jbe@154
|
1308 }
|
jbe@175
|
1309 // all other datatypes are considered an error:
|
jbe@166
|
1310 return luaL_error(L, "JSON export not possible for values of type \"%s\"", lua_typename(L, lua_type(L, json_export_internal_value_idx)));
|
jbe@154
|
1311 }
|
jbe@154
|
1312
|
jbe@175
|
1313 // encodes a JSON document (passed as argument):
|
jbe@164
|
1314 static int json_export(lua_State *L) {
|
jbe@175
|
1315 // stack shall contain one function argument:
|
jbe@164
|
1316 lua_settop(L, 1);
|
jbe@175
|
1317 // call json_export_internal function with proper arguments:
|
jbe@164
|
1318 lua_pushcfunction(L, json_export_internal);
|
jbe@164
|
1319 lua_pushnil(L);
|
jbe@164
|
1320 lua_pushinteger(L, 0);
|
jbe@164
|
1321 lua_pushvalue(L, 1);
|
jbe@164
|
1322 lua_call(L, 3, 1);
|
jbe@175
|
1323 // return result:
|
jbe@164
|
1324 return 1;
|
jbe@164
|
1325 }
|
jbe@164
|
1326
|
jbe@175
|
1327 // encodes a JSON document (passed as first argument)
|
jbe@175
|
1328 // with indentation (indentation string may be passed as second argument):
|
jbe@164
|
1329 static int json_pretty(lua_State *L) {
|
jbe@175
|
1330 // stack shall contain two function arguments:
|
jbe@164
|
1331 lua_settop(L, 2);
|
jbe@175
|
1332 // call json_export_internal function with proper arguments:
|
jbe@164
|
1333 lua_pushcfunction(L, json_export_internal);
|
jbe@164
|
1334 if (lua_isnil(L, 2)) lua_pushliteral(L, " ");
|
jbe@164
|
1335 else lua_pushvalue(L, 2);
|
jbe@164
|
1336 lua_pushinteger(L, 0);
|
jbe@164
|
1337 lua_pushvalue(L, 1);
|
jbe@164
|
1338 lua_call(L, 3, 1);
|
jbe@175
|
1339 // return result:
|
jbe@164
|
1340 return 1;
|
jbe@164
|
1341 }
|
jbe@164
|
1342
|
jbe@149
|
1343 // functions in library module:
|
jbe@121
|
1344 static const struct luaL_Reg json_module_functions[] = {
|
jbe@133
|
1345 {"object", json_object},
|
jbe@173
|
1346 {"array", json_array},
|
jbe@121
|
1347 {"import", json_import},
|
jbe@154
|
1348 {"export", json_export},
|
jbe@164
|
1349 {"pretty", json_pretty},
|
jbe@173
|
1350 {"get", json_get},
|
jbe@173
|
1351 {"type", json_type},
|
jbe@173
|
1352 {"set", json_set},
|
jbe@121
|
1353 {NULL, NULL}
|
jbe@121
|
1354 };
|
jbe@121
|
1355
|
jbe@149
|
1356 // metamethods for JSON objects, JSON arrays, and unknown JSON collections (object or array):
|
jbe@126
|
1357 static const struct luaL_Reg json_metatable_functions[] = {
|
jbe@130
|
1358 {"__len", json_len},
|
jbe@130
|
1359 {"__index", json_index},
|
jbe@130
|
1360 {"__newindex", json_newindex},
|
jbe@135
|
1361 {"__pairs", json_pairs},
|
jbe@134
|
1362 {"__ipairs", json_ipairs},
|
jbe@160
|
1363 {"__tostring", json_export},
|
jbe@126
|
1364 {NULL, NULL}
|
jbe@126
|
1365 };
|
jbe@126
|
1366
|
jbe@157
|
1367 // metamethods for JSON null marker:
|
jbe@157
|
1368 static const struct luaL_Reg json_nullmark_metamethods[] = {
|
jbe@157
|
1369 {"__tostring", json_nullmark_tostring},
|
jbe@157
|
1370 {NULL, NULL}
|
jbe@157
|
1371 };
|
jbe@157
|
1372
|
jbe@149
|
1373 // initializes json library:
|
jbe@121
|
1374 int luaopen_json(lua_State *L) {
|
jbe@149
|
1375 // empty stack:
|
jbe@126
|
1376 lua_settop(L, 0);
|
jbe@149
|
1377 // push library module onto stack position 1:
|
jbe@149
|
1378 lua_newtable(L);
|
jbe@149
|
1379 // register library functions:
|
jbe@149
|
1380 luaL_setfuncs(L, json_module_functions, 0);
|
jbe@149
|
1381 // create and store objectmt:
|
jbe@138
|
1382 lua_newtable(L);
|
jbe@138
|
1383 luaL_setfuncs(L, json_metatable_functions, 0);
|
jbe@144
|
1384 json_regstore(L, objectmt);
|
jbe@149
|
1385 // create and store arraymt:
|
jbe@138
|
1386 lua_newtable(L);
|
jbe@138
|
1387 luaL_setfuncs(L, json_metatable_functions, 0);
|
jbe@144
|
1388 json_regstore(L, arraymt);
|
jbe@149
|
1389 // create and store ephemeron table to store shadow tables for each JSON object/array
|
jbe@149
|
1390 // to allow NULL values returned as nil
|
jbe@149
|
1391 lua_newtable(L);
|
jbe@138
|
1392 lua_newtable(L); // metatable for ephemeron table
|
jbe@121
|
1393 lua_pushliteral(L, "__mode");
|
jbe@121
|
1394 lua_pushliteral(L, "k");
|
jbe@138
|
1395 lua_rawset(L, -3);
|
jbe@138
|
1396 lua_setmetatable(L, -2);
|
jbe@144
|
1397 json_regstore(L, shadowtbl);
|
jbe@157
|
1398 // set metatable of null marker and make it available through library module:
|
jbe@157
|
1399 json_pushnullmark(L);
|
jbe@157
|
1400 lua_newtable(L);
|
jbe@157
|
1401 luaL_setfuncs(L, json_nullmark_metamethods, 0);
|
jbe@157
|
1402 lua_setmetatable(L, -2);
|
jbe@157
|
1403 lua_setfield(L, 1, "null");
|
jbe@157
|
1404 // return library module (that's expected on top of stack):
|
jbe@121
|
1405 return 1;
|
jbe@121
|
1406 }
|