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⚡ Bolt: Optimize operator initialization by removing heap allocations #44

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Merged
ashyanSpada merged 1 commit into from
Mar 23, 2026
Merged

⚡ Bolt: Optimize operator initialization by removing heap allocations #44

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3 changes: 3 additions & 0 deletions .jules/bolt.md
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Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
## 2024-05-24 - Avoid vec! for constant collections in initialization loops
**Learning:** Initializing maps/operator managers by iterating over `vec![...]` causes unnecessary heap allocations. Using array literals `[...]` is significantly more efficient since the size is known at compile time and the arrays can be stack-allocated or embedded directly into the binary.
**Action:** Always prefer iterating over array literals instead of `vec![...]` for statically known collections, especially in hot paths or initialization loops.
2 changes: 1 addition & 1 deletion benches/display_expression.rs
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@@ -1,4 +1,4 @@
use criterion::{criterion_group, criterion_main, Criterion, black_box};
use criterion::{black_box, criterion_group, criterion_main, Criterion};
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Copilot AI Mar 22, 2026

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The only change here is reordering the criterion imports, which is unrelated to the operator initialization optimization described in the PR. Consider dropping this from the PR or documenting why it’s included, to avoid mixing perf changes with style-only diffs.

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@gemini-code-assist gemini-code-assist Bot Mar 22, 2026

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medium

This appears to be a stylistic change that reorders the imports. While not harmful, it's unrelated to the performance optimizations in this PR. To keep pull requests focused on a single concern, it's good practice to exclude unrelated changes. Please consider reverting this change from this PR.

use expression_engine::{parse_expression, ExprAST};

fn bench_display_expression(c: &mut Criterion) {
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15 changes: 8 additions & 7 deletions src/operator.rs
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Expand Up @@ -57,7 +57,8 @@ impl InfixOpManager {
use InfixOpType::*;
self.register("=", 20, SETTER, RIGHT, Arc::new(|_, right| Ok(right)));

for op in vec!["+=", "-=", "*=", "/=", "%="] {
// Iterate over an array literal `[...]` instead of `vec![...]` to avoid heap allocations
for op in ["+=", "-=", "*=", "/=", "%="] {
self.register(
op,
20,
Expand Down Expand Up @@ -88,7 +89,7 @@ impl InfixOpManager {
);
}

for op in vec!["<<=", ">>=", "&=", "^=", "|="] {
for op in ["<<=", ">>=", "&=", "^=", "|="] {
self.register(
op,
20,
Expand All @@ -109,7 +110,7 @@ impl InfixOpManager {
);
}

for (op, precedence) in vec![("||", 40), ("&&", 50)] {
for (op, precedence) in [("||", 40), ("&&", 50)] {
self.register(
op,
precedence,
Expand All @@ -127,7 +128,7 @@ impl InfixOpManager {
);
}

for op in vec!["<", "<=", ">", ">="] {
for op in ["<", "<=", ">", ">="] {
self.register(
op,
60,
Expand All @@ -148,7 +149,7 @@ impl InfixOpManager {
);
}

for op in vec!["==", "!="] {
for op in ["==", "!="] {
self.register(
op,
60,
Expand All @@ -166,7 +167,7 @@ impl InfixOpManager {
);
}

for (op, precedence) in vec![("|", 70), ("^", 80), ("&", 90), ("<<", 100), (">>", 100)] {
for (op, precedence) in [("|", 70), ("^", 80), ("&", 90), ("<<", 100), (">>", 100)] {
self.register(
op,
precedence,
Expand All @@ -187,7 +188,7 @@ impl InfixOpManager {
);
}

for (op, precedence) in vec![("+", 110), ("-", 110), ("*", 120), ("/", 120), ("%", 120)] {
for (op, precedence) in [("+", 110), ("-", 110), ("*", 120), ("/", 120), ("%", 120)] {
self.register(
op,
precedence,
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14 changes: 4 additions & 10 deletions src/parser.rs
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Expand Up @@ -52,22 +52,16 @@ impl<'a> fmt::Display for ExprAST<'a> {
Self::Unary(op, rhs) => {
write!(f, "Unary AST: Op: {}, Rhs: {}", op, rhs)
}
Self::Binary(op, lhs, rhs) => write!(
f,
"Binary AST: Op: {}, Lhs: {}, Rhs: {}",
op,
lhs,
rhs
),
Self::Binary(op, lhs, rhs) => {
write!(f, "Binary AST: Op: {}, Lhs: {}, Rhs: {}", op, lhs, rhs)
}
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Self::Postfix(lhs, op) => {
write!(f, "Postfix AST: Lhs: {}, Op: {}", lhs, op,)
}
Self::Ternary(condition, lhs, rhs) => write!(
f,
"Ternary AST: Condition: {}, Lhs: {}, Rhs: {}",
condition,
lhs,
rhs
condition, lhs, rhs
),
Self::Reference(name) => write!(f, "Reference AST: reference: {}", name),
Self::Function(name, params) => {
Expand Down
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