This section covers functions for accessing and modifying object attributes using the C API and following Teascript’s special method rules. Unlike raw map operations, these functions respect the special methods getattr and setattr, as well as operator overload methods [] and []= defined on classes to be used for instances and userdata. They provide the same semantics as the obj.key and obj[key] syntax in Tea code.

tea_has_attr()

bool tea_has_attr(tea_State* T, int obj, const char* key);

Checks whether the object at obj has an attribute named key.

Arguments

  • T: Teascript state
  • obj: Stack index of the object to query
  • key: Name of the attribute to loop up

Returns

true if the attribute exists; false otherwise.

Example

tea_new_map(T);
tea_push_integer(T, 42);
tea_set_attr(T, -2, "answer");

bool has = tea_has_attr(T, -1, "answer");  /* has = true */
has = tea_has_attr(T, -1, "missing");      /* has = false */

See Also

tea_get_attr, tea_set_attr, tea_delete_attr

tea_get_attr()

void tea_get_attr(tea_State* T, int obj, const char* key);
...obj...
...obj...value

Pushes the value of the attribute named key of the object at obj onto the stack. This respect the object’s special methods, so it may invoke getter methods.

Arguments

  • T: Teascript state
  • obj: Stack index of the object
  • key: Name of the attribute to retrieve

Example

tea_new_module(T, "mymod");
tea_push_integer(T, 7);
tea_set_attr(T, -2, "version");

tea_get_attr(T, -1, "version");   /* pushes 7 */

See Also

tea_set_attr, tea_has_attr, tea_get_key

tea_set_attr()

void tea_set_attr(tea_State* T, int obj, const char* key);
...obj...value
...obj...

Pops the value from the top of the stack and assigns it to the attribute named key of the object at obj. This respects the object’s special methods, so it may invoke setter methods or fail silently if the attribute is read-only.

Arguments

  • T: Teascript state
  • obj: Stack index of the object
  • key: Name of the attribute to set

Example

tea_new_module(T, "mymod");       /* [module] */
tea_push_integer(T, 1);
tea_set_attr(T, -2, "version");   /* module.version = 1 */
tea_push_string(T, "beta");
tea_set_attr(T, -2, "channel");   /* module.channel = "beta" */

See Also

tea_get_attr, tea_delete_attr, tea_set_key

tea_delete_attr()

void tea_delete_attr(tea_State* T, int obj, const char* key);
...obj...
...obj...

Deletes the attribute named key from the object at obj.

Arguments

  • T: Teascript state
  • obj: Stack index of the object
  • key: Name of the attribute to delete

Example

tea_new_module(T, "mymod");
tea_push_integer(T, 1);
tea_set_attr(T, -2, "version");

tea_delete_attr(T, -1, "version");   /* module.version removed */

See Also

tea_set_attr, tea_has_attr, tea_delete_key

tea_get_index()

void tea_get_index(tea_State* T, int obj);
...obj...key
...obj...obj(key)

Pops the key from the top of the stack and pushes the value obtained by indexing the object at obj with that key, using the [] operator method if defined (i.e. equivalent to obj[key] in Teascript).

Arguments

  • T: Teascript state
  • obj: Stack index of the object to index

Example

tea_new_map(T);
tea_push_string(T, "name");
tea_push_string(T, "Tea");
tea_set_key(T, -3, "name");       /* map["name"] = "Tea" */

tea_push_string(T, "name");
tea_get_index(T, -2);             /* pushes "Tea" */

See Also

tea_set_index, tea_get_key, tea_get_field

tea_set_index()

void tea_set_index(tea_State* T, int obj);
...obj...keyvalue
...obj...

Pops the key and value from the top of the stack and performs obj[key] = value, using the []= operator method if defined.

Arguments

  • T: Teascript state
  • obj: Stack index of the object to index

Example

tea_new_map(T);                   /* [map] */
tea_push_string(T, "lang");
tea_push_string(T, "Tea");
tea_set_index(T, -3);             /* map["lang"] = "Tea" */
tea_pop(T, 1);                    /* [map] */

See Also

tea_get_index, tea_set_key, tea_set_field