Struct magnus::Binding

#[repr(transparent)]
pub struct Binding(_);

A Value known to be an instance of Binding.

All Value methods should be available on this type through Deref, but some may be missed by this documentation.

Implementations

impl Binding

pub fn new() -> Self

👎Deprecated since 0.2.0: this will no longer function as of Ruby 3.2

Available on ruby_lte_3_1 only.

Create a new Binding from the current Ruby execution context.

Examples

use magnus::Binding;

let binding = Binding::new();

pub fn from_value(val: Value) -> Option<Self>

Return Some(Binding) if val is a Binding, None otherwise.

pub fn eval<T, U>(&self, s: T) -> Result<U, Error>where
    T: Into<RString>,
    U: TryConvert,

Evaluate a string of Ruby code within the binding’s context.

Examples

use magnus::{eval, Binding};

let binding = eval::<Binding>("binding").unwrap();
assert_eq!(binding.eval::<_, i64>("1 + 2").unwrap(), 3);

pub fn local_variable_get<N, T>(&self, name: N) -> Result<T, Error>where
    N: Into<Symbol>,
    T: TryConvert,

Get the named local variable from the binding.

Returns Ok(T) if the method returns without error and the return value converts to a T, or returns Err if the local variable does not exist or the conversion fails.

Examples

use magnus::{eval, Binding, Value};

let binding = eval::<Binding>("binding").unwrap();
binding.local_variable_set("a", 1);
assert_eq!(binding.local_variable_get::<_, i64>("a").unwrap(), 1);
assert!(binding.local_variable_get::<_, Value>("b").is_err());

pub fn local_variable_set<N, T>(&self, name: N, val: T)where
    N: Into<Symbol>,
    T: Into<Value>,

Set the named local variable in the binding.

Examples

use magnus::{eval, Binding};

let binding = eval::<Binding>("binding").unwrap();
binding.local_variable_set("a", 1);
assert_eq!(binding.local_variable_get::<_, i64>("a").unwrap(), 1);

Methods from Deref<Target = Value>

pub unsafe fn to_s(&self) -> Result<Cow<'_, str>, Error>

Convert self to a Rust string.

Safety

This may return a direct view of memory owned and managed by Ruby. Ruby may modify or free the memory backing the returned str, the caller must ensure this does not happen.

This can be used safely by immediately calling into_owned on the return value.

Examples

use magnus::{eval, QTRUE};

let value = QTRUE;
// safe as we neve give Ruby a chance to free the string.
let s = unsafe { value.to_s() }.unwrap().into_owned();
assert_eq!(s, "true");

pub unsafe fn classname(&self) -> Cow<'_, str>

Return the name of self’s class.

Safety

Ruby may modify or free the memory backing the returned str, the caller must ensure this does not happen.

This can be used safely by immediately calling into_owned on the return value.

Examples

use magnus::{eval, RHash};

let value = RHash::new();
// safe as we never give Ruby a chance to free the string.
let s = unsafe { value.classname() }.into_owned();
assert_eq!(s, "Hash");

Trait Implementations

impl Clone for Binding

fn clone(&self) -> Binding

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Binding

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for Binding

type Target = Value

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Display for Binding

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<Binding> for Value

fn from(val: Binding) -> Self

Converts to this type from the input type.

impl Object for Binding

fn define_singleton_method<M>(self, name: &str, func: M) -> Result<(), Error>where
    M: Method,

Define a singleton method in self’s scope.

fn ivar_get<T, U>(self, name: T) -> Result<U, Error>where
    T: Into<Id>,
    U: TryConvert,

Get the value for the instance variable name within self’s scope.

fn ivar_set<T, U>(self, name: T, value: U) -> Result<(), Error>where
    T: Into<Id>,
    U: Into<Value>,

Set the value for the instance variable name within self’s scope.

fn singleton_class(self) -> Result<RClass, Error>

Finds or creates the singleton class of self.

fn extend_object(self, module: RModule) -> Result<(), Error>

Extend self with module.

impl TryConvert for Binding

fn try_convert(val: Value) -> Result<Self, Error>

Convert val into Self.

impl Copy for Binding

impl ReprValue for Binding