From 932a70d0c25a3d7b8cfb31788348e850648e2aa1 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Sat, 27 Aug 2022 19:55:02 +0300 Subject: refactor(tvix/eval): track with stack size as a simple integer The `With` struct no longer contained any internals after the cleanup logic for the stack had been moved into Compiler::compile_with, leaving the `Vec` to essentially act as a counter for the number of things on the with stack. That's inefficient of course, so with this commit it actually becomes an integer (with an encapsulated API within scope::Scope). Change-Id: I67a00987fc8b46b30d369a96d41e83c8af5b1998 Reviewed-on: https://cl.tvl.fyi/c/depot/+/6311 Tested-by: BuildkiteCI Reviewed-by: sterni --- tvix/eval/src/compiler/scope.rs | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) (limited to 'tvix/eval/src/compiler/scope.rs') diff --git a/tvix/eval/src/compiler/scope.rs b/tvix/eval/src/compiler/scope.rs index 93aa39a0d86f..e295731e3258 100644 --- a/tvix/eval/src/compiler/scope.rs +++ b/tvix/eval/src/compiler/scope.rs @@ -65,10 +65,6 @@ pub struct Local { pub used: bool, } -/// Represents an entry on the runtime with-stack. -#[derive(Debug)] -pub struct With {} - /// Represents the current position of a local as resolved in a scope. pub enum LocalPosition { /// Local is not known in this scope. @@ -112,9 +108,8 @@ pub struct Scope { // How many scopes "deep" are these locals? pub scope_depth: usize, - // Stack indices of attribute sets currently in scope through - // `with`. - pub with_stack: Vec, + // Current size of the `with`-stack at runtime. + with_stack_size: usize, // Users are allowed to override globally defined symbols like // `true`, `false` or `null` in scopes. We call this "scope @@ -151,6 +146,22 @@ impl Scope { .retain(|_, poisoned_at| *poisoned_at != depth); } + /// Increase the `with`-stack size of this scope. + pub fn push_with(&mut self) { + self.with_stack_size += 1; + } + + /// Decrease the `with`-stack size of this scope. + pub fn pop_with(&mut self) { + self.with_stack_size -= 1; + } + + /// Does this scope currently require dynamic runtime resolution + /// of identifiers that could not be found? + pub fn has_with(&self) -> bool { + self.with_stack_size > 0 + } + /// Resolve the stack index of a statically known local. pub fn resolve_local(&mut self, name: &str) -> LocalPosition { for (idx, local) in self.locals.iter_mut().enumerate().rev() { -- cgit 1.4.1