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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5
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jbe@137
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6 #define JSON_UPVAL_LIBRARY lua_upvalueindex(1)
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jbe@137
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7 #define JSON_UPVAL_NULLMARK lua_upvalueindex(2)
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jbe@137
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8 #define JSON_UPVAL_SHADOWTBL lua_upvalueindex(3)
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jbe@137
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9 #define JSON_UPVAL_TYPES lua_upvalueindex(4)
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jbe@137
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10 #define JSON_UPVAL_METATABLE lua_upvalueindex(5)
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jbe@137
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11 #define JSON_UPVAL_PAIRS_ITERFUNC lua_upvalueindex(6)
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jbe@137
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12 #define JSON_UPVAL_IPAIRS_ITERFUNC lua_upvalueindex(7)
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jbe@123
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13
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jbe@136
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14 // marks a table as JSON object or JSON array:
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jbe@136
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15 // (returns its modified argument or a new table if argument is nil)
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jbe@136
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16 static int json_mark(lua_State *L, const char *marker) {
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jbe@136
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17 // if argument is nil, then create new table:
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jbe@136
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18 if (lua_isnoneornil(L, 1)) {
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jbe@136
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19 lua_settop(L, 0);
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jbe@136
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20 lua_newtable(L);
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jbe@136
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21 // skip testing of existing shadow table:
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jbe@136
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22 goto json_object_create_shadow_table;
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jbe@136
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23 }
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jbe@136
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24 lua_pushvalue(L, 1);
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jbe@136
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25 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
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jbe@136
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26 if (lua_isnil(L, -1)) {
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jbe@136
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27 json_object_create_shadow_table:
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jbe@136
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28 // set shadow table:
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jbe@136
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29 lua_pushvalue(L, 1);
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jbe@136
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30 lua_newtable(L);
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jbe@136
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31 lua_rawset(L, JSON_UPVAL_SHADOWTBL);
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jbe@136
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32 }
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jbe@136
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33 // set metatable:
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jbe@136
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34 lua_pushvalue(L, JSON_UPVAL_METATABLE);
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jbe@136
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35 lua_setmetatable(L, 1);
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jbe@136
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36 // mark table as JSON object or as JSON array
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jbe@136
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37 lua_pushvalue(L, 1);
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jbe@136
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38 lua_pushstring(L, marker);
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jbe@136
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39 lua_rawset(L, JSON_UPVAL_TYPES);
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jbe@136
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40 return 1;
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jbe@136
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41 }
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jbe@136
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42
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jbe@136
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43 // marks a table as JSON object:
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jbe@136
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44 // (returns its modified argument or a new table if argument is nil)
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jbe@136
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45 static int json_object(lua_State *L) {
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jbe@136
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46 return json_mark(L, "object");
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jbe@136
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47 }
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jbe@136
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48
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jbe@136
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49 // marks a table as JSON array:
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jbe@136
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50 // (returns its modified argument or a new table if argument is nil)
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jbe@136
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51 static int json_array(lua_State *L) {
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jbe@136
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52 return json_mark(L, "array");
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jbe@136
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53 }
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54
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jbe@124
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55 #define JSON_STATE_VALUE 0
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jbe@124
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56 #define JSON_STATE_OBJECT_KEY 1
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jbe@124
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57 #define JSON_STATE_OBJECT_KEY_TERMINATOR 2
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jbe@124
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58 #define JSON_STATE_OBJECT_VALUE 3
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jbe@124
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59 #define JSON_STATE_OBJECT_SEPARATOR 4
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jbe@124
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60 #define JSON_STATE_ARRAY_VALUE 5
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jbe@124
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61 #define JSON_STATE_ARRAY_SEPARATOR 6
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jbe@124
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62 #define JSON_STATE_END 7
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63
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jbe@136
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64 // decodes a JSON document:
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65 static int json_import(lua_State *L) {
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66 const char *str; // string to parse
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67 size_t total; // total length of string to parse
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68 size_t pos = 0; // current position in string to parse
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69 size_t level = 0; // nested levels of objects/arrays currently being processed
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70 int mode = JSON_STATE_VALUE; // state of parser
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71 char c; // variable to store a single character to be processed
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jbe@136
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72 luaL_Buffer luabuf; // Lua buffer to decode (possibly escaped) strings
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73 char *cbuf; // C buffer to decode (possibly escaped) strings
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jbe@136
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74 size_t writepos; // write position of decoded strings in C buffer
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jbe@136
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75 // require string as first argument:
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76 str = luaL_checklstring(L, 1, &total);
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jbe@136
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77 // if string contains a NULL byte, this is a syntax error
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jbe@136
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78 if (strlen(str) != total) goto json_import_syntax_error;
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jbe@136
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79 // main loop of parser:
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jbe@136
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80 json_import_loop:
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jbe@136
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81 // skip whitespace and store next character in variable 'c':
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jbe@121
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82 while (c = str[pos], c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == '\f') pos++;
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jbe@136
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83 // switch statement to handle certain (single) characters:
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jbe@121
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84 switch (c) {
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jbe@136
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85 // handle end of JSON document:
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jbe@121
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86 case 0:
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jbe@136
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87 // if end of JSON document was expected, then return top element of stack as result:
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jbe@124
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88 if (mode == JSON_STATE_END) return 1;
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jbe@136
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89 // otherwise, the JSON document was malformed:
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jbe@121
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90 json_import_unexpected_eof:
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jbe@121
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91 lua_pushnil(L);
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jbe@121
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92 if (level == 0) lua_pushliteral(L, "Empty string");
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93 else lua_pushliteral(L, "Unexpected end of JSON document");
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jbe@121
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94 return 2;
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jbe@136
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95 // new JSON object:
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jbe@121
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96 case '{':
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jbe@136
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97 // if a JSON object is not expected here, then return an error:
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jbe@124
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98 if (mode != JSON_STATE_VALUE && mode != JSON_STATE_OBJECT_VALUE && mode != JSON_STATE_ARRAY_VALUE)
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jbe@121
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99 goto json_import_syntax_error;
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jbe@136
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100 // consume input character:
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jbe@121
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101 pos++;
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jbe@136
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102 // create JSON object on stack:
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jbe@136
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103 lua_newtable(L);
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jbe@136
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104 // set metatable of JSON object:
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jbe@125
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105 lua_pushvalue(L, JSON_UPVAL_METATABLE);
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jbe@125
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106 lua_setmetatable(L, -2);
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jbe@136
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107 // mark JSON object as JSON object (as opposed to JSON array):
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jbe@127
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108 lua_pushvalue(L, -1);
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jbe@127
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109 lua_pushliteral(L, "object");
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jbe@127
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110 lua_rawset(L, JSON_UPVAL_TYPES);
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jbe@136
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111 // create internal shadow table on stack:
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jbe@136
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112 lua_newtable(L);
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jbe@136
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113 // register internal shadow table:
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jbe@123
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114 lua_pushvalue(L, -2);
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jbe@123
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115 lua_pushvalue(L, -2);
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jbe@130
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116 lua_rawset(L, JSON_UPVAL_SHADOWTBL);
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jbe@136
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117 // increment level:
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jbe@121
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118 level++;
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jbe@136
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119 // expect object key (or end of object) and continue with loop:
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jbe@136
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120 mode = JSON_STATE_OBJECT_KEY;
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jbe@121
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121 goto json_import_loop;
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jbe@136
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122 // new JSON array:
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jbe@121
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123 case '[':
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jbe@136
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124 // if a JSON array is not expected here, then return an error:
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jbe@124
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125 if (mode != JSON_STATE_VALUE && mode != JSON_STATE_OBJECT_VALUE && mode != JSON_STATE_ARRAY_VALUE)
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jbe@121
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126 goto json_import_syntax_error;
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jbe@136
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127 // consume input character:
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jbe@121
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128 pos++;
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jbe@136
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129 // create JSON array on stack:
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jbe@136
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130 lua_newtable(L);
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jbe@136
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131 // set metatable of JSON array:
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jbe@125
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132 lua_pushvalue(L, JSON_UPVAL_METATABLE);
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jbe@125
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133 lua_setmetatable(L, -2);
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jbe@136
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134 // mark JSON array as JSON array (as opposed to JSON object):
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jbe@127
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135 lua_pushvalue(L, -1);
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jbe@127
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136 lua_pushliteral(L, "array");
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jbe@127
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137 lua_rawset(L, JSON_UPVAL_TYPES);
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jbe@136
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138 // create internal shadow table on stack:
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jbe@136
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139 lua_newtable(L);
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jbe@136
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140 // register internal shadow table:
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jbe@123
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141 lua_pushvalue(L, -2);
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jbe@123
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142 lua_pushvalue(L, -2);
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jbe@130
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143 lua_rawset(L, JSON_UPVAL_SHADOWTBL);
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jbe@136
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144 // increment level:
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jbe@121
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145 level++;
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jbe@136
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146 // expect array value (or end of array) and continue with loop:
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jbe@136
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147 mode = JSON_STATE_ARRAY_VALUE;
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jbe@121
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148 goto json_import_loop;
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jbe@136
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149 // end of JSON object:
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jbe@121
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150 case '}':
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jbe@136
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151 // if end of JSON object is not expected here, then return an error:
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jbe@124
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152 if (mode != JSON_STATE_OBJECT_KEY && mode != JSON_STATE_OBJECT_SEPARATOR)
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jbe@121
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153 goto json_import_syntax_error;
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jbe@136
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154 // jump to common code for end of JSON object and JSON array:
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jbe@121
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155 goto json_import_close;
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jbe@136
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156 // end of JSON array:
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jbe@121
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157 case ']':
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jbe@136
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158 // if end of JSON array is not expected here, then return an error:
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jbe@124
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159 if (mode != JSON_STATE_ARRAY_VALUE && mode != JSON_STATE_ARRAY_SEPARATOR)
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jbe@121
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160 goto json_import_syntax_error;
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jbe@136
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161 // continue with common code for end of JSON object and JSON array:
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jbe@136
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162 // common code for end of JSON object or JSON array:
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jbe@121
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163 json_import_close:
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jbe@136
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164 // consume input character:
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jbe@121
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165 pos++;
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jbe@136
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166 // pop shadow table:
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jbe@136
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167 lua_pop(L, 1);
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jbe@136
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168 // check if nested:
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jbe@121
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169 if (--level) {
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jbe@136
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170 // if nested, then check if outer(!) structure is an array or object:
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jbe@136
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171 lua_pushvalue(L, c == '}' ? -4 : -3);
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jbe@136
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172 lua_rawget(L, JSON_UPVAL_TYPES);
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jbe@136
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173 if (lua_tostring(L, -1)[0] == 'a') {
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jbe@136
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174 // select array value processing:
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jbe@124
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175 mode = JSON_STATE_ARRAY_VALUE;
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jbe@121
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176 } else {
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jbe@136
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177 // select object value processing:
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jbe@124
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178 mode = JSON_STATE_OBJECT_VALUE;
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jbe@121
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179 }
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jbe@136
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180 // pop JSON type from stack (from rawget JSON_UPVAL_TYPES):
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jbe@136
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181 lua_pop(L, 1);
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jbe@136
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182 // store value in outer structure:
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jbe@121
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183 goto json_import_process_value;
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jbe@121
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184 }
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jbe@136
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185 // if not nested, then expect end of JSON document and continue with loop:
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jbe@136
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186 mode = JSON_STATE_END;
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jbe@121
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187 goto json_import_loop;
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jbe@136
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188 // key terminator:
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jbe@121
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189 case ':':
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jbe@136
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190 // if key terminator is not expected here, then return an error:
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jbe@124
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191 if (mode != JSON_STATE_OBJECT_KEY_TERMINATOR)
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jbe@121
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192 goto json_import_syntax_error;
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jbe@136
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193 // consume input character:
|
jbe@121
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194 pos++;
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jbe@136
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195 // set state of parser and continue with loop:
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jbe@124
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196 mode = JSON_STATE_OBJECT_VALUE;
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jbe@121
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197 goto json_import_loop;
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jbe@136
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198 // value terminator (NOTE: trailing comma at end of value or key-value list is tolerated by this parser)
|
jbe@121
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199 case ',':
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jbe@136
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200 // change parser state accordingly:
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jbe@124
|
201 if (mode == JSON_STATE_OBJECT_SEPARATOR) {
|
jbe@124
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202 mode = JSON_STATE_OBJECT_KEY;
|
jbe@124
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203 } else if (mode == JSON_STATE_ARRAY_SEPARATOR) {
|
jbe@124
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204 mode = JSON_STATE_ARRAY_VALUE;
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jbe@121
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205 } else {
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jbe@136
|
206 // if value terminator is not expected here, then return an error:
|
jbe@136
|
207 goto json_import_syntax_error;
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jbe@121
|
208 }
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jbe@136
|
209 // consume input character:
|
jbe@121
|
210 pos++;
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jbe@136
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211 // continue with loop:
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jbe@121
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212 goto json_import_loop;
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jbe@136
|
213 // string literal:
|
jbe@121
|
214 case '"':
|
jbe@136
|
215 // prepare buffer to decode string (with maximum possible length) and set write position to zero:
|
jbe@121
|
216 cbuf = luaL_buffinitsize(L, &luabuf, total-pos);
|
jbe@121
|
217 writepos = 0;
|
jbe@136
|
218 // consume quote character:
|
jbe@121
|
219 pos++;
|
jbe@136
|
220 // read next character until encountering end quote:
|
jbe@121
|
221 while ((c = str[pos++]) != '"') {
|
jbe@121
|
222 if (c == 0) {
|
jbe@136
|
223 // handle unexpected end-of-string:
|
jbe@121
|
224 goto json_import_unexpected_eof;
|
jbe@121
|
225 } else if (c < 32 || c == 127) {
|
jbe@136
|
226 // do not allow ASCII control characters:
|
jbe@136
|
227 // NOTE: illegal UTF-8 sequences and extended control characters are not sanitized
|
jbe@136
|
228 // by this parser to allow different encodings than Unicode
|
jbe@121
|
229 lua_pushnil(L);
|
jbe@121
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230 lua_pushliteral(L, "Unexpected control character in JSON string");
|
jbe@121
|
231 return 2;
|
jbe@121
|
232 } else if (c == '\\') {
|
jbe@136
|
233 // read next char after backslash escape:
|
jbe@121
|
234 c = str[pos++];
|
jbe@121
|
235 switch (c) {
|
jbe@136
|
236 // unexpected end-of-string:
|
jbe@121
|
237 case 0:
|
jbe@121
|
238 goto json_import_unexpected_eof;
|
jbe@136
|
239 // unescaping of quotation mark, slash, and backslash:
|
jbe@121
|
240 case '"':
|
jbe@121
|
241 case '/':
|
jbe@121
|
242 case '\\':
|
jbe@121
|
243 cbuf[writepos++] = c;
|
jbe@121
|
244 break;
|
jbe@136
|
245 // unescaping of backspace:
|
jbe@121
|
246 case 'b':
|
jbe@121
|
247 cbuf[writepos++] = '\b';
|
jbe@121
|
248 break;
|
jbe@136
|
249 // unescaping of form-feed:
|
jbe@121
|
250 case 'f':
|
jbe@121
|
251 cbuf[writepos++] = '\f';
|
jbe@121
|
252 break;
|
jbe@136
|
253 // unescaping of new-line:
|
jbe@121
|
254 case 'n':
|
jbe@121
|
255 cbuf[writepos++] = '\n';
|
jbe@121
|
256 break;
|
jbe@136
|
257 // unescaping of carriage-return:
|
jbe@121
|
258 case 'r':
|
jbe@121
|
259 cbuf[writepos++] = '\r';
|
jbe@121
|
260 break;
|
jbe@136
|
261 // unescaping of tabulator:
|
jbe@121
|
262 case 't':
|
jbe@121
|
263 cbuf[writepos++] = '\t';
|
jbe@121
|
264 break;
|
jbe@136
|
265 // unescaping of UTF-16 characters
|
jbe@121
|
266 case 'u':
|
jbe@121
|
267 lua_pushnil(L);
|
jbe@121
|
268 lua_pushliteral(L, "JSON unicode escape sequences are not implemented yet"); // TODO
|
jbe@121
|
269 return 2;
|
jbe@136
|
270 // unexpected escape sequence:
|
jbe@121
|
271 default:
|
jbe@121
|
272 lua_pushnil(L);
|
jbe@121
|
273 lua_pushliteral(L, "Unexpected string escape sequence in JSON document");
|
jbe@121
|
274 return 2;
|
jbe@121
|
275 }
|
jbe@121
|
276 } else {
|
jbe@136
|
277 // normal character:
|
jbe@121
|
278 cbuf[writepos++] = c;
|
jbe@121
|
279 }
|
jbe@121
|
280 }
|
jbe@136
|
281 // process buffer to Lua string:
|
jbe@121
|
282 luaL_pushresultsize(&luabuf, writepos);
|
jbe@136
|
283 // continue with processing of decoded string:
|
jbe@121
|
284 goto json_import_process_value;
|
jbe@121
|
285 }
|
jbe@136
|
286 // process values whose type is is not deducible from a single character:
|
jbe@136
|
287 if ((c >= '0' && c <= '9') || c == '-' || c == '+') {
|
jbe@136
|
288 // numbers:
|
jbe@122
|
289 char *endptr;
|
jbe@122
|
290 double numval;
|
jbe@122
|
291 numval = strtod(str+pos, &endptr);
|
jbe@122
|
292 if (endptr == str+pos) goto json_import_syntax_error;
|
jbe@122
|
293 pos += endptr - (str+pos);
|
jbe@122
|
294 lua_pushnumber(L, numval);
|
jbe@122
|
295 } else if (!strncmp(str+pos, "true", 4)) {
|
jbe@136
|
296 // consume 4 input characters for "true":
|
jbe@121
|
297 pos += 4;
|
jbe@136
|
298 // put Lua true value on stack:
|
jbe@136
|
299 lua_pushboolean(L, 1);
|
jbe@121
|
300 } else if (!strncmp(str+pos, "false", 5)) {
|
jbe@136
|
301 // consume 5 input characters for "false":
|
jbe@121
|
302 pos += 5;
|
jbe@136
|
303 // put Lua false value on stack:
|
jbe@136
|
304 lua_pushboolean(L, 0);
|
jbe@121
|
305 } else if (!strncmp(str+pos, "null", 4)) {
|
jbe@136
|
306 // consume 4 input characters for "null":
|
jbe@136
|
307 pos += 4;
|
jbe@136
|
308 // put special null-marker on stack:
|
jbe@130
|
309 lua_pushvalue(L, JSON_UPVAL_NULLMARK);
|
jbe@121
|
310 } else {
|
jbe@136
|
311 // all other cases are a syntax error:
|
jbe@121
|
312 goto json_import_syntax_error;
|
jbe@121
|
313 }
|
jbe@136
|
314 // process a decoded value or key value pair (expected on top of Lua stack):
|
jbe@136
|
315 json_import_process_value:
|
jbe@121
|
316 switch (mode) {
|
jbe@136
|
317 // an object key has been read:
|
jbe@124
|
318 case JSON_STATE_OBJECT_KEY:
|
jbe@136
|
319 // if an object key is not a string, then this is a syntax error:
|
jbe@121
|
320 if (lua_type(L, -1) != LUA_TSTRING) goto json_import_syntax_error;
|
jbe@136
|
321 // expect key terminator and continue with loop:
|
jbe@124
|
322 mode = JSON_STATE_OBJECT_KEY_TERMINATOR;
|
jbe@121
|
323 goto json_import_loop;
|
jbe@136
|
324 // a key value pair has been read:
|
jbe@124
|
325 case JSON_STATE_OBJECT_VALUE:
|
jbe@136
|
326 // store key value pair in outer shadow table:
|
jbe@130
|
327 lua_rawset(L, -3);
|
jbe@136
|
328 // expect value terminator (or end of object) and continue with loop:
|
jbe@124
|
329 mode = JSON_STATE_OBJECT_SEPARATOR;
|
jbe@121
|
330 goto json_import_loop;
|
jbe@136
|
331 // an array value has been read:
|
jbe@124
|
332 case JSON_STATE_ARRAY_VALUE:
|
jbe@136
|
333 // store value in outer shadow table:
|
jbe@136
|
334 lua_rawseti(L, -2, lua_rawlen(L, -2) + 1);
|
jbe@136
|
335 // expect value terminator (or end of object) and continue with loop:
|
jbe@124
|
336 mode = JSON_STATE_ARRAY_SEPARATOR;
|
jbe@121
|
337 goto json_import_loop;
|
jbe@136
|
338 // a single value has been read:
|
jbe@124
|
339 case JSON_STATE_VALUE:
|
jbe@136
|
340 // leave value on top of stack, expect end of JSON document, and continue with loop:
|
jbe@124
|
341 mode = JSON_STATE_END;
|
jbe@121
|
342 goto json_import_loop;
|
jbe@121
|
343 }
|
jbe@136
|
344 // syntax error handling (only reachable by goto statement):
|
jbe@136
|
345 json_import_syntax_error:
|
jbe@121
|
346 lua_pushnil(L);
|
jbe@121
|
347 lua_pushliteral(L, "Syntax error in JSON document");
|
jbe@121
|
348 return 2;
|
jbe@121
|
349 }
|
jbe@121
|
350
|
jbe@137
|
351 // gets a value or its type from a JSON document (first argument)
|
jbe@137
|
352 // optionally using a path (variable number of keys after first argument):
|
jbe@137
|
353 static int json_path(lua_State *L, int type_mode) {
|
jbe@130
|
354 int argc;
|
jbe@130
|
355 int idx = 2;
|
jbe@137
|
356 // store number of arguments:
|
jbe@130
|
357 argc = lua_gettop(L);
|
jbe@137
|
358 // follow path, starting with first argument as "current value":
|
jbe@126
|
359 lua_pushvalue(L, 1);
|
jbe@137
|
360 // process each "path key":
|
jbe@130
|
361 while (idx <= argc) {
|
jbe@137
|
362 // if "current value" is nil, then the path cannot be walked and nil is returned:
|
jbe@137
|
363 if (lua_isnil(L, -1)) return 1;
|
jbe@137
|
364 // try to get shadow table of "current value":
|
jbe@130
|
365 lua_pushvalue(L, -1);
|
jbe@130
|
366 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
|
jbe@126
|
367 if (lua_isnil(L, -1)) {
|
jbe@137
|
368 // if no shadow table is found,
|
jbe@137
|
369 // drop nil from stack:
|
jbe@126
|
370 lua_pop(L, 1);
|
jbe@130
|
371 if (lua_type(L, -1) == LUA_TTABLE) {
|
jbe@137
|
372 // if "current value" is a table,
|
jbe@137
|
373 // get "next value" using the "path key":
|
jbe@130
|
374 lua_pushvalue(L, idx++);
|
jbe@130
|
375 lua_gettable(L, -2);
|
jbe@130
|
376 } else {
|
jbe@137
|
377 // if "current value" is not a table,
|
jbe@137
|
378 // then the path cannot be walked and nil is returned:
|
jbe@130
|
379 lua_pushnil(L);
|
jbe@137
|
380 return 1;
|
jbe@130
|
381 }
|
jbe@130
|
382 } else {
|
jbe@137
|
383 // if a shadow table is found,
|
jbe@137
|
384 // set "current value" to its shadow table:
|
jbe@130
|
385 lua_replace(L, -2);
|
jbe@137
|
386 // get "next value" using the "path key":
|
jbe@130
|
387 lua_pushvalue(L, idx++);
|
jbe@130
|
388 lua_rawget(L, -2);
|
jbe@126
|
389 }
|
jbe@137
|
390 // the "next value" replaces the "current value":
|
jbe@130
|
391 lua_replace(L, -2);
|
jbe@126
|
392 }
|
jbe@137
|
393 if (!type_mode) {
|
jbe@137
|
394 // if a value (and not its type) was requested,
|
jbe@137
|
395 // check if value is the null-marker, and store nil on top of Lua stack in that case:
|
jbe@130
|
396 if (lua_rawequal(L, -1, JSON_UPVAL_NULLMARK)) lua_pushnil(L);
|
jbe@137
|
397 } else {
|
jbe@137
|
398 // if the type was requested,
|
jbe@137
|
399 // check if value is the null-marker:
|
jbe@130
|
400 if (lua_rawequal(L, -1, JSON_UPVAL_NULLMARK)) {
|
jbe@137
|
401 // if yes, store string "null" on top of Lua stack:
|
jbe@130
|
402 lua_pushliteral(L, "null");
|
jbe@137
|
403 } else {
|
jbe@137
|
404 // otherwise,
|
jbe@137
|
405 // try to read type ("object" or "array") from internal type table:
|
jbe@137
|
406 lua_pushvalue(L, -1);
|
jbe@137
|
407 lua_rawget(L, JSON_UPVAL_TYPES);
|
jbe@137
|
408 // if no entry is found in the internal type table, get the Lua type:
|
jbe@137
|
409 if (lua_isnil(L, -1)) lua_pushstring(L, lua_typename(L, lua_type(L, -2)));
|
jbe@126
|
410 }
|
jbe@126
|
411 }
|
jbe@137
|
412 // return the top most value on the Lua stack:
|
jbe@137
|
413 return 1;
|
jbe@130
|
414 }
|
jbe@130
|
415
|
jbe@137
|
416 // gets a value from a JSON document (first argument)
|
jbe@137
|
417 // optionally using a path (variable number of keys after first argument):
|
jbe@130
|
418 static int json_get(lua_State *L) {
|
jbe@137
|
419 return json_path(L, 0);
|
jbe@130
|
420 }
|
jbe@130
|
421
|
jbe@137
|
422 // gets a value's type from a JSON document (first argument)
|
jbe@137
|
423 // optionally using a path (variable number of keys after first argument):
|
jbe@130
|
424 static int json_type(lua_State *L) {
|
jbe@137
|
425 return json_path(L, 1);
|
jbe@130
|
426 }
|
jbe@130
|
427
|
jbe@137
|
428 // checks if a value in a JSON document (first argument) is null:
|
jbe@130
|
429 static int json_isnull(lua_State *L) {
|
jbe@137
|
430 const char *jsontype;
|
jbe@137
|
431 lua_getfield(L, JSON_UPVAL_LIBRARY, "type");
|
jbe@137
|
432 lua_insert(L, 1);
|
jbe@137
|
433 lua_call(L, lua_gettop(L) - 1, 1);
|
jbe@137
|
434 jsontype = lua_tostring(L, -1);
|
jbe@137
|
435 if (jsontype && !strcmp(jsontype, "null")) lua_pushboolean(L, 1);
|
jbe@137
|
436 else lua_pushboolean(L, 0);
|
jbe@137
|
437 return 1;
|
jbe@130
|
438 }
|
jbe@130
|
439
|
jbe@131
|
440 static int json_setnull(lua_State *L) {
|
jbe@131
|
441 lua_settop(L, 2);
|
jbe@131
|
442 lua_pushvalue(L, JSON_UPVAL_METATABLE);
|
jbe@131
|
443 lua_setmetatable(L, 1);
|
jbe@131
|
444 lua_pushvalue(L, 1);
|
jbe@131
|
445 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
|
jbe@131
|
446 if (lua_isnil(L, -1)) {
|
jbe@131
|
447 lua_newtable(L);
|
jbe@131
|
448 lua_pushvalue(L, 1);
|
jbe@131
|
449 lua_pushvalue(L, -2);
|
jbe@131
|
450 lua_rawset(L, JSON_UPVAL_SHADOWTBL);
|
jbe@131
|
451 }
|
jbe@131
|
452 lua_pushvalue(L, 2);
|
jbe@131
|
453 lua_pushvalue(L, JSON_UPVAL_NULLMARK);
|
jbe@131
|
454 lua_rawset(L, -3);
|
jbe@131
|
455 return 0;
|
jbe@131
|
456 }
|
jbe@131
|
457
|
jbe@130
|
458 static int json_len(lua_State *L) {
|
jbe@130
|
459 lua_settop(L, 1);
|
jbe@130
|
460 lua_pushvalue(L, 1);
|
jbe@130
|
461 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
|
jbe@130
|
462 if (lua_isnil(L, -1)) lua_pop(L, 1);
|
jbe@130
|
463 lua_pushinteger(L, lua_rawlen(L, -1));
|
jbe@123
|
464 return 1;
|
jbe@123
|
465 }
|
jbe@123
|
466
|
jbe@130
|
467 static int json_index(lua_State *L) {
|
jbe@130
|
468 lua_settop(L, 2);
|
jbe@130
|
469 lua_pushvalue(L, 1);
|
jbe@130
|
470 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
|
jbe@130
|
471 if (lua_isnil(L, -1)) return 1;
|
jbe@130
|
472 lua_pushvalue(L, 2);
|
jbe@130
|
473 lua_rawget(L, -2);
|
jbe@130
|
474 if (lua_rawequal(L, -1, JSON_UPVAL_NULLMARK)) lua_pushnil(L);
|
jbe@127
|
475 return 1;
|
jbe@127
|
476 }
|
jbe@127
|
477
|
jbe@130
|
478 static int json_newindex(lua_State *L) {
|
jbe@130
|
479 lua_settop(L, 3);
|
jbe@123
|
480 lua_pushvalue(L, 1);
|
jbe@130
|
481 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
|
jbe@130
|
482 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@130
|
483 lua_replace(L, 1);
|
jbe@130
|
484 lua_rawset(L, 1);
|
jbe@121
|
485 return 1;
|
jbe@121
|
486 }
|
jbe@121
|
487
|
jbe@135
|
488 static int json_pairs_iterfunc(lua_State *L) {
|
jbe@135
|
489 lua_settop(L, 2);
|
jbe@135
|
490 lua_pushvalue(L, 1);
|
jbe@135
|
491 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
|
jbe@135
|
492 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@135
|
493 lua_pushvalue(L, 2);
|
jbe@135
|
494 if (!lua_next(L, -2)) return 0;
|
jbe@135
|
495 if (lua_rawequal(L, -1, JSON_UPVAL_NULLMARK)) {
|
jbe@135
|
496 lua_pop(L, 1);
|
jbe@135
|
497 lua_pushnil(L);
|
jbe@135
|
498 }
|
jbe@135
|
499 return 2;
|
jbe@135
|
500 }
|
jbe@135
|
501
|
jbe@135
|
502 static int json_pairs(lua_State *L) {
|
jbe@135
|
503 lua_pushvalue(L, JSON_UPVAL_PAIRS_ITERFUNC);
|
jbe@135
|
504 lua_pushvalue(L, 1);
|
jbe@135
|
505 lua_pushnil(L);
|
jbe@135
|
506 return 3;
|
jbe@135
|
507 }
|
jbe@135
|
508
|
jbe@134
|
509 static int json_ipairs_iterfunc(lua_State *L) {
|
jbe@134
|
510 int idx;
|
jbe@134
|
511 lua_settop(L, 2);
|
jbe@134
|
512 idx = lua_tointeger(L, 2) + 1;
|
jbe@134
|
513 lua_pushvalue(L, 1);
|
jbe@134
|
514 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
|
jbe@134
|
515 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@134
|
516 lua_rawgeti(L, -1, idx);
|
jbe@134
|
517 if (lua_isnil(L, -1)) return 0;
|
jbe@134
|
518 lua_pushinteger(L, idx);
|
jbe@134
|
519 if (lua_rawequal(L, -2, JSON_UPVAL_NULLMARK)) lua_pushnil(L);
|
jbe@134
|
520 else lua_pushvalue(L, -2);
|
jbe@134
|
521 return 2;
|
jbe@134
|
522 }
|
jbe@134
|
523
|
jbe@134
|
524 static int json_ipairs(lua_State *L) {
|
jbe@134
|
525 lua_pushvalue(L, JSON_UPVAL_IPAIRS_ITERFUNC);
|
jbe@134
|
526 lua_pushvalue(L, 1);
|
jbe@134
|
527 lua_pushinteger(L, 0);
|
jbe@134
|
528 return 3;
|
jbe@134
|
529 }
|
jbe@134
|
530
|
jbe@121
|
531 static const struct luaL_Reg json_module_functions[] = {
|
jbe@133
|
532 {"object", json_object},
|
jbe@133
|
533 {"array", json_array},
|
jbe@121
|
534 {"import", json_import},
|
jbe@130
|
535 {"get", json_get},
|
jbe@127
|
536 {"type", json_type},
|
jbe@123
|
537 {"isnull", json_isnull},
|
jbe@131
|
538 {"setnull", json_setnull},
|
jbe@121
|
539 {NULL, NULL}
|
jbe@121
|
540 };
|
jbe@121
|
541
|
jbe@126
|
542 static const struct luaL_Reg json_metatable_functions[] = {
|
jbe@130
|
543 {"__len", json_len},
|
jbe@130
|
544 {"__index", json_index},
|
jbe@130
|
545 {"__newindex", json_newindex},
|
jbe@135
|
546 {"__pairs", json_pairs},
|
jbe@134
|
547 {"__ipairs", json_ipairs},
|
jbe@126
|
548 {NULL, NULL}
|
jbe@126
|
549 };
|
jbe@126
|
550
|
jbe@121
|
551 int luaopen_json(lua_State *L) {
|
jbe@126
|
552 lua_settop(L, 0);
|
jbe@137
|
553 lua_newtable(L); // 1: library table on stack position
|
jbe@137
|
554 lua_pushvalue(L, 1); // 2: copy of library table
|
jbe@137
|
555 lua_newtable(L); // 3: table used as JSON NULL value in internal shadow tables
|
jbe@137
|
556 lua_newtable(L); // 4: ephemeron table to store shadow tables for each JSON object/array to allow NULL values returned as nil
|
jbe@137
|
557 lua_newtable(L); // 5: ephemeron table to store the type of the JSON object/array
|
jbe@137
|
558 lua_newtable(L); // 6: metatable for ephemeron tables
|
jbe@121
|
559 lua_pushliteral(L, "__mode");
|
jbe@121
|
560 lua_pushliteral(L, "k");
|
jbe@137
|
561 lua_rawset(L, 6);
|
jbe@137
|
562 lua_pushvalue(L, 6); // 7: cloned metatable reference
|
jbe@130
|
563 lua_setmetatable(L, 4);
|
jbe@137
|
564 lua_setmetatable(L, 5);
|
jbe@137
|
565 lua_newtable(L); // 6: metatable for JSON objects and JSON arrays
|
jbe@126
|
566 lua_pushvalue(L, 2);
|
jbe@126
|
567 lua_pushvalue(L, 3);
|
jbe@127
|
568 lua_pushvalue(L, 4);
|
jbe@130
|
569 lua_pushvalue(L, 5);
|
jbe@137
|
570 lua_pushvalue(L, 6);
|
jbe@137
|
571 lua_pushcclosure(L, json_pairs_iterfunc, 5); // 7: iteration function for pairs
|
jbe@135
|
572 lua_pushvalue(L, 2);
|
jbe@135
|
573 lua_pushvalue(L, 3);
|
jbe@135
|
574 lua_pushvalue(L, 4);
|
jbe@135
|
575 lua_pushvalue(L, 5);
|
jbe@137
|
576 lua_pushvalue(L, 6);
|
jbe@137
|
577 lua_pushcclosure(L, json_ipairs_iterfunc, 5); // 8: iteration function for ipairs
|
jbe@137
|
578 lua_pushvalue(L, 6);
|
jbe@134
|
579 lua_pushvalue(L, 2);
|
jbe@134
|
580 lua_pushvalue(L, 3);
|
jbe@134
|
581 lua_pushvalue(L, 4);
|
jbe@134
|
582 lua_pushvalue(L, 5);
|
jbe@134
|
583 lua_pushvalue(L, 6);
|
jbe@135
|
584 lua_pushvalue(L, 7);
|
jbe@137
|
585 lua_pushvalue(L, 8);
|
jbe@137
|
586 luaL_setfuncs(L, json_metatable_functions, 7);
|
jbe@135
|
587 lua_setfield(L, 1, "metatable");
|
jbe@137
|
588 luaL_setfuncs(L, json_module_functions, 7);
|
jbe@121
|
589 return 1;
|
jbe@121
|
590 }
|