pulley_interpreter/interp/
match_loop.rs

1//! Implementation of the interpreter loop for Pulley with a simple `match`
2//! statement.
3//!
4//! This module is notably in contrast to the `tail_loop.rs` which implements
5//! the interpreter loop with tail calls. It's predicted that tail calls are a
6//! more performant solution but that's also not available on stable Rust today,
7//! so this module instead compiles on stable Rust.
8//!
9//! This interpreter loop is a simple `loop` with a "moral `match`" despite not
10//! actually having one here. The `Decoder` API is used to dispatch to the
11//! `OpVisitor` trait implementation on `Interpreter<'_>`. The literal `match`
12//! is embedded within the `Decoder::decode_one` function.
13//!
14//! Note that as of the time of this writing there hasn't been much performance
15//! analysis of this loop just yet. It's probably too simple to compile well and
16//! will probably need tweaks to make it more performant.
17
18use super::*;
19
20impl Interpreter<'_> {
21    pub fn run(self) -> Done {
22        let mut decoder = Decoder::new();
23        let mut visitor = debug::Debug(self);
24        loop {
25            // Here `decode_one` will call the appropriate `OpVisitor` method on
26            // `self` via the trait implementation in the module above this.
27            // That'll return whether we should keep going or exit the loop,
28            // which is then done here with a conditional `break`.
29            //
30            // This will then continue indefinitely until the bytecode says it's
31            // done. Note that only trusted bytecode is interpreted here.
32            match decoder.decode_one(&mut visitor) {
33                Ok(ControlFlow::Continue(())) => {}
34                Ok(ControlFlow::Break(done)) => break done,
35            }
36        }
37    }
38}
pulley_interpreter/interp/match_loop.rs

pulley_interpreter/interp/
match_loop.rs
