Bug 4348 – std.container.SList append

Status
RESOLVED
Resolution
WONTFIX
Severity
enhancement
Priority
P2
Component
phobos
Product
D
Version
D2
Platform
All
OS
All
Creation time
2010-06-19T12:52:00Z
Last change time
2010-06-20T03:31:03Z
Assigned to
nobody
Creator
bearophile_hugs

Comments

Comment #0 by bearophile_hugs — 2010-06-19T12:52:03Z
This shows how you can append to a std.container.SList: import std.container: SList; void main() { auto l = SList!int(1, 2); l.insertAfter(l[], 3); } But the standard D syntax too can be supported, despite it's O(n): import std.container: SList; void main() { auto l = SList!int(1, 2); l ~= 3; } (The member function "insertFront" might be named "prepend", that is shorter , equally readable and contains no upper case letters).
Comment #1 by andrei — 2010-06-19T14:51:02Z
~= is only for containers that can implement it in time independent of the size of the container. Writing s.insertAfter(s[], value) hints the user that the cost is higher (i.e. proportional to the length of s[]).
Comment #2 by bearophile_hugs — 2010-06-19T15:20:42Z
Answer to Comment 1: thank you for your answer, I didn't know about this rule. In arrays the append can require a full array copy, so it can be O(n), but it's (hopefully) O(1) on amortized time. If this rule is present and well established then you can close this bug report (the suggestion about the "prepend" name is for you, but you can ignore it if you don't like it). Another possibility is to find a compromise: instead of writing something hairy like: s.insertAfter(s[], value) You can use: s.linearAppend(value) That is less noisy and equally clear in its complexity :-)