Tape

fidget_core::eval

Trait Tape 

Source 
pub trait Tape:
    Send
    + Sync
    + Clone {
    type Storage: Default;

    // Required methods
    fn recycle(self) -> Option<Self::Storage>;
    fn vars(&self) -> &VarMap;
    fn output_count(&self) -> usize;
}
Expand description

A tape represents something that can be evaluated by an evaluator

It includes some kind of storage (which could be empty) and the ability to look up variable mapping.

Tapes may be shared between threads, so they should be cheap to clone (i.e. a wrapper around an Arc<..>).

Required Associated Types§

Source

type Storage: Default

Associated type for this tape’s data storage

Required Methods§

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fn recycle(self) -> Option<Self::Storage>

Tries to retrieve the internal storage from this tape

This matters most for JIT evaluators, whose tapes are regions of executable memory-mapped RAM (which is expensive to map and unmap).

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fn vars(&self) -> &VarMap

Returns a mapping from Var to evaluation index

This must be identical to Function::vars on the Function which produced this tape.

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fn output_count(&self) -> usize

Returns the number of outputs written by this tape

The order of outputs is set by the caller at tape construction, so we don’t need a map to determine the index of a particular output (unlike variables).

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors§