PHP弱数据类型的内部实现

PHP那个该死的若类型是怎么实现的

打开php代码中Zend.h和Zend_types.h可以看到有如下定义：

typedef union _zvalue_value { long lval; /* 长整形 */ double dval; /* 双精度 */ struct { char *val; int len; } str; /*字符串*/ HashTable *ht; /*hash表 */ zend_object obj; /*PHP对象存储结构*/ } zvalue_value; struct _zval_struct { zvalue_value value; /*值*/ zend_uchar type; /*当前类型*/ zend_uchar is_ref; /*。。。。。。。。。。。。。。看起来是是否被引用了*/ zend_ushort refcount; /*引用计数器*/ }; typedef struct _zval_struct zval; typedef zval pval; /*这玩意就是一个句柄表么*/ typedef unsigned int zend_object_handle; typedef struct _zend_object_handlers zend_object_handlers; typedef struct _zend_object_value { zend_object_handle handle; zend_object_handlers *handlers; } zend_object_value; /*对象结构体*/ struct _zend_object_handlers { /* general object functions */ zend_object_add_ref_t add_ref; zend_object_del_ref_t del_ref; zend_object_clone_obj_t clone_obj; /* individual object functions */ zend_object_read_property_t read_property; zend_object_write_property_t write_property; zend_object_read_dimension_t read_dimension; zend_object_write_dimension_t write_dimension; zend_object_get_property_ptr_ptr_t get_property_ptr_ptr; zend_object_get_t get; zend_object_set_t set; zend_object_has_property_t has_property; zend_object_unset_property_t unset_property; zend_object_has_dimension_t has_dimension; zend_object_unset_dimension_t unset_dimension; zend_object_get_properties_t get_properties; zend_object_get_method_t get_method; zend_object_call_method_t call_method; zend_object_get_constructor_t get_constructor; zend_object_get_class_entry_t get_class_entry; zend_object_get_class_name_t get_class_name; zend_object_compare_t compare_objects; zend_object_cast_t cast_object; zend_object_count_elements_t count_elements; zend_object_get_debug_info_t get_debug_info; zend_object_get_closure_t get_closure; }

这个结构体里面实现了：长整型，双精度浮点，字符串，hash表，还有对象（zend_object_value）。就是zval和pval两个结构。