Attribute Macro ext_php_rs::php_extern [−][src]
#[php_extern]
Expand description
Attribute used to annotate extern
blocks which are deemed as PHP functions.
This allows you to ‘import’ PHP functions into Rust so that they can be called like regular
Rust functions. Parameters can be any type that implements IntoZval
, and the return type
can be anything that implements From<Zval>
(notice how Zval
is consumed rather than
borrowed in this case).
Panics
The function can panic when called under a few circumstances:
- The function could not be found or was not callable.
- One of the parameters could not be converted into a
Zval
. - The actual function call failed internally.
- The output
Zval
could not be parsed into the output type.
The last point can be important when interacting with functions that return unions, such as
strpos
which can return an integer or a boolean. In this case, a Zval
should be
returned as parsing a boolean to an integer is invalid, and vice versa.
Example
This extern
block imports the strpos
function from PHP. Notice that the string parameters
can take either String
or &str
, the optional parameter offset
is an Option<i64>
,
and the return value is a Zval
as the return type is an integer-boolean union.
#[php_extern]
extern "C" {
fn strpos(haystack: &str, needle: &str, offset: Option<i64>) -> Zval;
}
#[php_function]
pub fn my_strpos() {
assert_eq!(unsafe { strpos("Hello", "e", None) }.long(), Some(1));
}