From d02e147295518b32f744a5906f8468cc6f2551bf Mon Sep 17 00:00:00 2001
From: stratact <stratact1@gmail.com>
Date: Mon, 28 May 2018 04:06:07 -0700
Subject: [PATCH] Use iterators to join strings rather than join from a
collected vec allocation
---
src/lib/parser/statement/case.rs | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/src/lib/parser/statement/case.rs b/src/lib/parser/statement/case.rs
index 75732370..10c37c33 100644
--- a/src/lib/parser/statement/case.rs
+++ b/src/lib/parser/statement/case.rs
@@ -36,7 +36,13 @@ pub(crate) fn parse_case<'a>(
binding = Some(splitter.next().ok_or(CaseError::NoBindVariable)?);
match splitter.next() {
Some("if") => {
- let string = splitter.collect::<Vec<_>>().join(" ");
+ // Joining by folding is more efficient than collecting into Vec and then joining
+ let mut string = splitter.fold(String::with_capacity(5), |mut state, element| {
+ state.push_str(element);
+ state.push(' ');
+ state
+ });
+ string.pop(); // Pop out the unneeded ' ' character
if string.is_empty() {
return Err(CaseError::NoConditional);
}
@@ -47,7 +53,13 @@ pub(crate) fn parse_case<'a>(
}
}
Some("if") => {
- let string = splitter.collect::<Vec<_>>().join(" ");
+ // Joining by folding is more efficient than collecting into Vec and then joining
+ let mut string = splitter.fold(String::with_capacity(5), |mut state, element| {
+ state.push_str(element);
+ state.push(' ');
+ state
+ });
+ string.pop(); // Pop out the unneeded ' ' character
if string.is_empty() {
return Err(CaseError::NoConditional);
}
--
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