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));
}