Linear time list operations#10
Open
haampie wants to merge 3 commits into
Open
Conversation
Signed-off-by: Harmen Stoppels <me@harmenstoppels.nl>
Signed-off-by: Harmen Stoppels <me@harmenstoppels.nl>
Signed-off-by: Harmen Stoppels <me@harmenstoppels.nl>
sethrj
approved these changes
May 15, 2026
sethrj
left a comment
sethrj
left a comment
There was a problem hiding this comment.
Very nice! Good testing and clever scripting.
Comment on lines
+169
to
+180
| setsep "$_dst"; _dst_sep="$sep" | ||
|
|
||
| if [ -z "$_prefix" ]; then | ||
| # Fast concatenation when no prefix is needed | ||
| IFS="$_dst_sep"; _ext_str="$*"; unset IFS | ||
| else | ||
| _ext_str="${_prefix}$1" | ||
| shift | ||
| for elt; do | ||
| _ext_str="${_ext_str}${_dst_sep}${_prefix}${elt}" | ||
| done | ||
| fi |
There was a problem hiding this comment.
Is there a nontrivial performance penalty for merging these and the similar lines at 135 into a single function, e.g. one that uses printf and is called with _ext_str="$(merge "$_dst" "$sep" "$_prefix" "$@")"? Hiding the symbol-filled code (or at least making clear that it's an exact duplicate) woudl be good.
Member
Author
There was a problem hiding this comment.
Yeah, this is a bit dense and repetitive... So far we've tried to avoid printf, or rather subshells "$(printf ...)". I'm not sure if it can be improved without subshells.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Avoids string concatenation overhead in extend and preextend
"tricks" used:
set --and"$*"with differentIFSfor fast concatenation, presumably linear complexity.In the included benchmark, runtime goes from 100ms to 21ms on my macbook.