1 /* Common operations. */ 2 3 #include <stdlib.h> 4 #include "ops.h" 5 #include "progconsts.h" 6 #include "progtypes.h" 7 8 /* Direct access and manipulation of static objects. */ 9 10 __attr __load_static(__ref parent, __ref obj) 11 { 12 __attr out = {.context=parent, .value=obj}; 13 return out; 14 } 15 16 /* Direct retrieval operations, returning and setting attributes. */ 17 18 __attr __load_via_object(__ref obj, int pos) 19 { 20 return obj->attrs[pos]; 21 } 22 23 __attr __load_via_class(__ref obj, int pos) 24 { 25 return __load_via_object(__get_class(obj), pos); 26 } 27 28 __attr __get_class_and_load(__ref obj, int pos) 29 { 30 if (__is_instance(obj)) 31 return __load_via_class(obj, pos); 32 else 33 return __load_via_object(obj, pos); 34 } 35 36 /* Direct storage operations. */ 37 38 int __store_via_object(__ref obj, int pos, __attr value) 39 { 40 obj->attrs[pos] = value; 41 return 1; 42 } 43 44 /* Introspection. */ 45 46 int __is_instance(__ref obj) 47 { 48 return obj->pos == __INSTANCEPOS; 49 } 50 51 __ref __get_class(__ref obj) 52 { 53 return __load_via_object(obj, __pos___class__).value; 54 } 55 56 __attr __get_class_attr(__ref obj) 57 { 58 return __load_via_object(obj, __pos___class__); 59 } 60 61 /* Attribute testing operations. */ 62 63 __ref __test_specific_instance(__ref obj, __ref type) 64 { 65 return __get_class(obj) == type ? obj : 0; 66 } 67 68 __ref __test_common_instance(__ref obj, int pos, int code) 69 { 70 return __HASATTR(__get_class(obj), pos, code) ? obj : 0; 71 } 72 73 __ref __test_common_object(__ref obj, int pos, int code) 74 { 75 return __test_common_type(obj, pos, code) || __test_common_instance(obj, pos, code) ? obj : 0; 76 } 77 78 __ref __test_common_type(__ref obj, int pos, int code) 79 { 80 return __HASATTR(obj, pos, code) ? obj : 0; 81 } 82 83 /* Attribute testing and retrieval operations. */ 84 85 __attr __check_and_load_via_class(__ref obj, int pos, int code) 86 { 87 return __check_and_load_via_object(__get_class(obj), pos, code); 88 } 89 90 __attr __check_and_load_via_object(__ref obj, int pos, int code) 91 { 92 return __HASATTR(obj, pos, code) ? __load_via_object(obj, pos) : __NULL; 93 } 94 95 __attr __check_and_load_via_any(__ref obj, int pos, int code) 96 { 97 __attr out = __check_and_load_via_object(obj, pos, code); 98 if (out.value == 0) 99 out = __check_and_load_via_class(obj, pos, code); 100 return out; 101 } 102 103 /* Attribute testing and storage operations. */ 104 105 int __check_and_store_via_object(__ref obj, int pos, int code, __attr value) 106 { 107 if (__HASATTR(obj, pos, code)) 108 { 109 __store_via_object(obj, pos, value); 110 return 1; 111 } 112 return 0; 113 } 114 115 int __check_and_store_via_any(__ref obj, int pos, int code, __attr value) 116 { 117 if (__check_and_store_via_object(obj, pos, code, value)) 118 return 1; 119 return __check_and_store_via_object(__get_class(obj), pos, code, value); 120 } 121 122 /* Context-related operations. */ 123 124 __attr __test_context(__ref context, __attr attr) 125 { 126 /* Preserve any existing instance context. */ 127 128 if (__is_instance(attr.context)) 129 return attr; 130 if (__is_instance(context) && __test_common_instance(context, __TYPEPOS(attr.context), __TYPECODE(attr.context))) 131 return __replace_context(context, attr); 132 if (!__is_instance(context) && __test_common_type(context, __TYPEPOS(attr.context), __TYPECODE(attr.context))) 133 return __update_context(context, attr); 134 135 /* NOTE: An error may be more appropriate. */ 136 137 return __NULL; 138 } 139 140 __attr __replace_context(__ref context, __attr attr) 141 { 142 __attr out; 143 144 /* Set the context. */ 145 146 out.context = context; 147 148 /* Reference a callable version of the attribute by obtaining the bound 149 method reference from the __fn__ special attribute. */ 150 151 out.value = __load_via_object(attr.value, __ATTRPOS(__fn__)).b; 152 return out; 153 } 154 155 __attr __update_context(__ref context, __attr attr) 156 { 157 __attr out = {context, .fn=attr.fn}; 158 return out; 159 } 160 161 /* Basic structure tests. */ 162 163 int __WITHIN(__ref obj, int pos) 164 { 165 return pos < obj->table->size; 166 } 167 168 int __HASATTR(__ref obj, int pos, int code) 169 { 170 return __WITHIN(obj, pos) && (obj->table->attrs[pos] == code); 171 } 172 173 /* Parameter position operations. */ 174 175 int __HASPARAM(const __ptable *ptable, int ppos, int pcode) 176 { 177 __param param; 178 179 if (ppos < ptable->size) 180 { 181 param = ptable->params[ppos]; 182 if (param.code == pcode) 183 return param.pos; 184 } 185 186 return -1; 187 } 188 189 /* Conversions. */ 190 191 __attr __CONTEXT_AS_VALUE(__attr attr) 192 { 193 __attr out; 194 out.context = attr.context; 195 out.value = attr.context; 196 return out; 197 } 198 199 /* Type testing. */ 200 201 __ref __ISFUNC(__ref obj) 202 { 203 return __test_specific_instance(obj, &__FUNCTION_TYPE); 204 } 205 206 int __ISNULL(__attr value) 207 { 208 /* (value.context == __NULL.context) is superfluous */ 209 return (value.value == 0); /* __NULL.value */ 210 } 211 212 /* Attribute codes and positions for type objects. */ 213 214 unsigned int __TYPECODE(__ref obj) 215 { 216 return obj->table->attrs[obj->pos]; 217 } 218 219 unsigned int __TYPEPOS(__ref obj) 220 { 221 return obj->pos; 222 } 223 224 /* Copying of structures. */ 225 226 __ref __COPY(__ref obj, int size) 227 { 228 __ref copy = calloc(1, size); 229 memcpy(copy, obj, size); 230 return copy; 231 }