Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Don't allocate a vec for repeat count if it's not used #292

Closed
wants to merge 1 commit into from
Closed

Don't allocate a vec for repeat count if it's not used #292

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
37 changes: 23 additions & 14 deletions peg-macros/translate.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -581,10 +581,27 @@ fn compile_expr(context: &Context, e: &SpannedExpr, result_used: bool) -> TokenS
BoundedRepeat::Both(ref min, ref max) => (min.clone(), max.clone()),
};

let (repeat_init, repeat_step, repeat_count) = if result_used {
(
quote_spanned! { span => let mut __repeat_value = vec!(); },
quote_spanned! { span => __repeat_value.push(__value); },
quote_spanned! { span => __repeat_value.len() },
)
} else if min.is_some() || max.is_some() || sep.is_some() {
(
quote_spanned! { span => let mut __repeat_count = 0usize; },
quote_spanned! { span => __repeat_count += 1; },
quote_spanned! { span => __repeat_count },
)
} else {
(quote!(), quote!(), quote!())
};


let match_sep = if let Some(sep) = sep {
let sep_inner = compile_expr(context, sep, false);
quote_spanned!{ span=>
let __pos = if __repeat_value.is_empty() { __pos } else {
let __pos = if #repeat_count == 0 { __pos } else {
let __sep_res = #sep_inner;
match __sep_res {
::peg::RuleResult::Matched(__newpos, _) => { __newpos },
Expand All @@ -602,23 +619,13 @@ fn compile_expr(context: &Context, e: &SpannedExpr, result_used: bool) -> TokenS
quote!(())
};

let (repeat_vec, repeat_step) =
if result_used || min.is_some() || max.is_some() || sep.is_some() {
(
Some(quote_spanned! { span => let mut __repeat_value = vec!(); }),
Some(quote_spanned! { span => __repeat_value.push(__value); }),
)
} else {
(None, None)
};

let max_check = max.map(|max| {
quote_spanned!{ span=> if __repeat_value.len() >= #max { break } }
quote_spanned!{ span=> if #repeat_count >= #max { break } }
});

let result_check = if let Some(min) = min {
quote_spanned!{ span=>
if __repeat_value.len() >= #min {
if #repeat_count >= #min {
::peg::RuleResult::Matched(__repeat_pos, #result)
} else {
::peg::RuleResult::Failed
Expand All @@ -629,8 +636,10 @@ fn compile_expr(context: &Context, e: &SpannedExpr, result_used: bool) -> TokenS
};

quote_spanned!{ span=> {
#![allow(clippy::len_zero)]

let mut __repeat_pos = __pos;
#repeat_vec
#repeat_init

loop {
let __pos = __repeat_pos;
Expand Down