Added '__count' metamethod to objects

This commit is contained in:
CPunch 2021-01-22 15:22:30 -06:00
parent 6b407534c0
commit 7c92749e0d
6 changed files with 51 additions and 8 deletions

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@ -1,4 +1,4 @@
# Prototype Objects
# Objects & Protos
Cosmo supports an eccentric form of Object-Oriented Programming through the use of Objects and Proto-Objects. Under the hood, these are the same datatype, however they can be chained to describe behaviors in relation to other Objects, operators, and provide stateful functions.
@ -64,7 +64,8 @@ Objects have two main ways of being declared, first was just shown in the above
```
proto Test
function __init(self)
// __init is required for an object to be instantiated, the 'self' passed is the newly allocated object with it's proto already set to
// __init is required for an object to be instantiated, the 'self' passed is the
// newly allocated object with it's proto already set
end
function print(self)
@ -74,7 +75,8 @@ end
var objTest = Test()
// the ':' operator is used to invoke a method. if the '.' operator is used instead, the raw closure will be given meaning the 'self' parameter won't be populated
// the ':' operator is used to invoke a method. if the '.' operator is used instead, the
// raw closure will be given meaning the 'self' parameter won't be populated
objTest:print()
objTest.print(objTest) // equivalent to invoking with ':'
@ -93,6 +95,7 @@ that are called on special operators.
| __newindex | `(<object>, key, newValue)` | Called on new index using the '[] = ' operator |
| __index | `(<object>, key)` -> `value` | Called on index using the '[]' operator |
| __tostring | `(<object>)` -> `<string>` | Called when tostring() is called on an object |
| __count | `(<object>)` -> `<number>` | Called when object is used with the '#' count operator |
| __iter | `(<object>)` -> `<object>` | Called when used in a for-each loop with the 'in' operator |
| __next | `(<object>)` -> `...` | Called on each iteration in a for-each loop, return values are passed as parameters in the loop |
| __getter | `[<string> fieldName : <function> getterMethod]` | Indexed & called on field get using the '.' operator |

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@ -472,6 +472,42 @@ cosmo_Number cosmoO_toNumber(CState *state, CObj *obj) {
}
}
int cosmoO_count(CState *state, CObj *obj) {
CObjObject *proto = cosmoO_grabProto(obj);
CValue res;
if (proto != NULL && cosmoO_getIString(state, proto, ISTRING_COUNT, &res)) {
cosmoV_pushValue(state, res);
cosmoV_pushValue(state, cosmoV_newObj(obj));
if (!cosmoV_call(state, 1, 1) != COSMOVM_OK) // call ret, we expect 1 return value of type <number>
return 0;
StkPtr ret = cosmoV_getTop(state, 0);
if (!IS_NUMBER(*ret)) {
cosmoV_error(state, "__count expected to return <number>, got %s!", cosmoV_typeStr(*ret));
return 0;
}
// return number
cosmoV_pop(state);
return (int)cosmoV_readNumber(*ret);
}
switch (obj->type) {
case COBJ_TABLE: { // returns the # of entries in the hash table
CObjTable *tbl = (CObjTable*)obj;
return cosmoT_count(&tbl->tbl);
}
case COBJ_STRING: { // returns the length of the string
CObjString *str = (CObjString*)obj;
return str->length;
}
default:
cosmoV_error(state, "Couldn't get # (count) of %s!", cosmoO_typeStr(obj));
return 0;
}
}
void printObject(CObj *o) {
switch (o->type) {
case COBJ_STRING: {

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@ -195,5 +195,6 @@ const char *cosmoO_typeStr(CObj* obj);
CObjString *cosmoO_toString(CState *state, CObj *obj);
cosmo_Number cosmoO_toNumber(CState *state, CObj *obj);
int cosmoO_count(CState *state, CObj *obj);
#endif

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@ -50,6 +50,7 @@ CState *cosmoV_newState() {
state->iStrings[ISTRING_TOSTRING] = cosmoO_copyString(state, "__tostring", 10);
state->iStrings[ISTRING_INDEX] = cosmoO_copyString(state, "__index", 7);
state->iStrings[ISTRING_NEWINDEX] = cosmoO_copyString(state, "__newindex", 10);
state->iStrings[ISTRING_COUNT] = cosmoO_copyString(state, "__count", 7);
// getters/setters
state->iStrings[ISTRING_GETTER] = cosmoO_copyString(state, "__getter", 8);

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@ -17,6 +17,7 @@ typedef enum IStringEnum {
ISTRING_TOSTRING, // __tostring
ISTRING_INDEX, // __index
ISTRING_NEWINDEX, // __newindex
ISTRING_COUNT, // __count
ISTRING_GETTER, // __getter
ISTRING_SETTER, // __setter
ISTRING_ITER, // __iter

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@ -979,17 +979,18 @@ int cosmoV_execute(CState *state) {
}
continue;
}
case OP_COUNT: { // pop 1 value off the stack & if it's a table return the amount of active entries it has
case OP_COUNT: {
StkPtr temp = cosmoV_getTop(state, 0);
if (!IS_TABLE(*temp)) {
cosmoV_error(state, "Expected table, got %s!", cosmoV_typeStr(*temp));
if (!IS_OBJ(*temp)) {
cosmoV_error(state, "Expected non-primitive, got %s!", cosmoV_typeStr(*temp));
return -1;
}
CObjTable *tbl = (CObjTable*)cosmoV_readObj(*temp);
int count = cosmoO_count(state, cosmoV_readObj(*temp));
cosmoV_pop(state);
cosmoV_pushNumber(state, cosmoT_count(&tbl->tbl)); // pushes the count onto the stack
cosmoV_pushNumber(state, count); // pushes the count onto the stack
continue;
}
case OP_CONCAT: {