pub trait Globals {
    type Value: Value;
    type Error;

    // Required methods
    fn set_global_variable<T>(
        &mut self,
        name: T,
        value: &Self::Value
    ) -> Result<(), Self::Error>
       where T: Into<Cow<'static, [u8]>>;
    fn unset_global_variable<T>(&mut self, name: T) -> Result<(), Self::Error>
       where T: Into<Cow<'static, [u8]>>;
    fn get_global_variable<T>(
        &mut self,
        name: T
    ) -> Result<Option<Self::Value>, Self::Error>
       where T: Into<Cow<'static, [u8]>>;
}
Expand description

Get and set global variables on an interpreter.

Global variables can be an arbitrary Ruby value. Variable names must start with $.

Required Associated Types§

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type Value: Value

Concrete value type for global variables.

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type Error

Concrete error type for failures manipulating global variables.

Required Methods§

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fn set_global_variable<T>( &mut self, name: T, value: &Self::Value ) -> Result<(), Self::Error>
where T: Into<Cow<'static, [u8]>>,

Set global variable pointed to by name to the given Ruby value.

§Errors

If the name is not a valid global name, an error is returned.

If there is insufficient capacity in the global storage, an error is returned.

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fn unset_global_variable<T>(&mut self, name: T) -> Result<(), Self::Error>
where T: Into<Cow<'static, [u8]>>,

Unset global variable pointed to by name.

Unsetting a global variable removes the name from the global storage table. Unset globals resolve to nil in the Ruby VM.

Unsetting a global that is currently unset is a no-op.

§Errors

If the name is not a valid global name, an error is returned.

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fn get_global_variable<T>( &mut self, name: T ) -> Result<Option<Self::Value>, Self::Error>
where T: Into<Cow<'static, [u8]>>,

Get the Ruby value stored in the global variable pointed to by name.

§Compatibility Notes

Getting a global that is currently may return Ok(None) even through a non-existent global resolves to nil in the Ruby VM. Consult the documentation on implementations of this trait for implementation-defined behavior.

§Errors

If the name is not a valid global name, an error is returned.

Object Safety§

This trait is not object safe.

Implementors§