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use std::{ffi::CString, mem::transmute};
use rb_sys::{
rb_define_singleton_method, rb_extend_object, rb_ivar_get, rb_ivar_set, rb_singleton_class,
};
use crate::{
class::RClass,
error::{protect, Error},
into_value::IntoValue,
method::Method,
module::RModule,
try_convert::TryConvert,
value::{private::ReprValue as _, IntoId, ReprValue, Value},
Ruby,
};
/// Functions available all non-immediate values.
pub trait Object: ReprValue + Copy {
/// Define a singleton method in `self`'s scope.
///
/// Singleton methods defined on a class are Ruby's method for implementing
/// 'class' methods.
///
/// # Examples
///
/// ```
/// use magnus::{function, prelude::*, rb_assert, Error, Ruby};
///
/// fn test() -> i64 {
/// 42
/// }
///
/// fn example(ruby: &Ruby) -> Result<(), Error> {
/// let module = ruby.define_module("Example")?;
/// module.define_singleton_method("test", function!(test, 0))?;
/// rb_assert!(ruby, "Example.test == 42");
///
/// Ok(())
/// }
/// # Ruby::init(example).unwrap()
/// ```
///
/// ```
/// use magnus::{function, prelude::*, rb_assert, Error, Ruby};
///
/// #[magnus::wrap(class = "Point", free_immediately, size)]
/// struct Point {
/// x: isize,
/// y: isize,
/// }
///
/// impl Point {
/// fn new(x: isize, y: isize) -> Self {
/// Self { x, y }
/// }
/// }
///
/// fn example(ruby: &Ruby) -> Result<(), Error> {
/// let class = ruby.define_class("Point", ruby.class_object())?;
/// class.define_singleton_method("new", function!(Point::new, 2))?;
///
/// rb_assert!(ruby, "Point.new(1, 2).is_a?(Point)");
///
/// Ok(())
/// }
/// # let _ = Point { x: 1, y: 2 }.x + Point { x: 3, y: 4 }.y;
/// # Ruby::init(example).unwrap()
/// ```
fn define_singleton_method<M>(self, name: &str, func: M) -> Result<(), Error>
where
M: Method,
{
debug_assert_value!(self);
let name = CString::new(name).unwrap();
protect(|| {
unsafe {
rb_define_singleton_method(
self.as_rb_value(),
name.as_ptr(),
transmute(func.as_ptr()),
M::arity().into(),
)
};
Ruby::get_with(self).qnil()
})?;
Ok(())
}
/// Get the value for the instance variable `name` within `self`'s scope.
///
/// Note, the `@` is part of the name. An instance variable can be set and
/// retrieved without a preceding `@` and it will work, but the instance
/// variable will be invisible to Ruby code.
///
/// # Examples
///
/// ```
/// use magnus::{prelude::*, Error, RObject, Ruby};
///
/// fn example(ruby: &Ruby) -> Result<(), Error> {
/// let val: RObject = ruby.eval(
/// r#"
/// class Example
/// def initialize(value)
/// @value = value
/// end
/// end
/// Example.new("foo")
/// "#,
/// )?;
///
/// assert_eq!(val.ivar_get::<_, String>("@value")?, "foo");
///
/// Ok(())
/// }
/// # Ruby::init(example).unwrap()
/// ```
fn ivar_get<T, U>(self, name: T) -> Result<U, Error>
where
T: IntoId,
U: TryConvert,
{
debug_assert_value!(self);
let id = name.into_id_with(&Ruby::get_with(self));
let res = unsafe { protect(|| Value::new(rb_ivar_get(self.as_rb_value(), id.as_rb_id()))) };
res.and_then(TryConvert::try_convert)
}
/// Set the value for the instance variable `name` within `self`'s scope.
///
/// Note, the `@` is part of the name. Setting an instance variable without
/// a preceding `@` will work, but the instance variable will be invisible
/// to Ruby code.
///
/// # Examples
///
/// ```
/// use magnus::{prelude::*, rb_assert, Error, RObject, Ruby};
///
/// fn example(ruby: &Ruby) -> Result<(), Error> {
/// let obj: RObject = ruby.eval(
/// r#"
/// class Example
/// def initialize(value)
/// @value = value
/// end
///
/// def value
/// @value
/// end
/// end
/// Example.new("foo")
/// "#,
/// )?;
///
/// obj.ivar_set("@value", "bar")?;
/// rb_assert!(ruby, r#"obj.value == "bar""#, obj);
///
/// Ok(())
/// }
/// # Ruby::init(example).unwrap()
/// ```
fn ivar_set<T, U>(self, name: T, value: U) -> Result<(), Error>
where
T: IntoId,
U: IntoValue,
{
debug_assert_value!(self);
let handle = Ruby::get_with(self);
let id = name.into_id_with(&handle);
let value = value.into_value_with(&handle);
unsafe {
protect(|| {
Value::new(rb_ivar_set(
self.as_rb_value(),
id.as_rb_id(),
value.as_rb_value(),
))
})
}?;
Ok(())
}
/// Finds or creates the singleton class of `self`.
///
/// Returns `Err` if `self` can not have a singleton class.
///
/// # Examples
///
/// ```
/// use magnus::{prelude::*, Error, Ruby};
///
/// fn example(ruby: &Ruby) -> Result<(), Error> {
/// assert!(ruby.str_new("example").singleton_class().is_ok());
///
/// Ok(())
/// }
/// # Ruby::init(example).unwrap()
/// ```
fn singleton_class(self) -> Result<RClass, Error> {
protect(|| unsafe {
RClass::from_rb_value_unchecked(rb_singleton_class(self.as_rb_value()))
})
}
/// Extend `self` with `module`.
///
/// # Examples
///
/// ```
/// use magnus::{function, prelude::*, rb_assert, Error, RObject, Ruby};
///
/// fn test() -> i64 {
/// 42
/// }
///
/// fn example(ruby: &Ruby) -> Result<(), Error> {
/// let module = ruby.module_new();
/// module.define_method("test", function!(test, 0))?;
///
/// let obj = RObject::try_convert(ruby.class_object().new_instance(())?)?;
/// obj.extend_object(module)?;
/// rb_assert!(ruby, "obj.test == 42", obj);
///
/// Ok(())
/// }
/// # Ruby::init(example).unwrap()
/// ```
fn extend_object(self, module: RModule) -> Result<(), Error> {
protect(|| {
unsafe { rb_extend_object(self.as_rb_value(), module.as_rb_value()) };
Ruby::get_with(self).qnil()
})?;
Ok(())
}
}