mirrors/TiddlyWiki5
1
0
Fork 0
mirror of https://github.com/Jermolene/TiddlyWiki5 synced 2024-11-09 11:29:58 +00:00
Code Issues Releases Wiki Activity

Clarify opposite handling of de-duplication order for unique Operator vs Dominant Append (#8357)

Browse Source
This commit is contained in:
springerspandrel 2024-07-09 11:34:18 -04:00 committed by GitHub
parent ad5661ef1c
commit 753b289ba9
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
2 changed files with 7 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
editions/tw5.com/tiddlers/concepts/Dominant Append.tid
View File

@ -1,5 +1,5 @@
created: 20150123220223000
modified: 20190610165255223
modified: 20240709151004998
tags: Filters
title: Dominant Append
type: text/vnd.tiddlywiki
@ -13,3 +13,5 @@ For example, if a selection contains `Andrew Becky Clara Daniel` and `Andrew Bar
This behaviour can cause unexpected results when working with [[Mathematics Operators]]. For example, `1 2 3 +[sum[]]` evaluates to `6`, as expected. But `1 1 1 +[sum[]]` evaluates to `1`. Removing the `+[sum[]]` from each filter reveals the problem: `1 2 3` evaluates to the list `1`, `2`, `3`, while `1 1 1` evaluates to the single item `1` due to de-duplication.
In such situations, the `=` prefix can be used to disable the de-duplication. For example, `=1 =1 =1 +[sum[]]` evaluates to `3` as expected. Alternatively, the [[split Operator]] can be used: `[[1,1,1]split[,]sum[]]`.
<<.tip """To build a list of unique values that retains only the <<.em earliest>> copy of each value (the opposite behavior from <<.link "Dominant Append" "Dominant Append">>), first use the <<.link `:all` "All Filter Run Prefix">> filter run prefix (or its short form `=`) to retain all duplicate values while building your list. Then finish your filter run with the <<.olink unique>> operator" to remove later duplicates.""">>

4
editions/tw5.com/tiddlers/filters/unique.tid
View File

@ -1,4 +1,6 @@
caption: unique
created: 20240709151018238
modified: 20240709151336906
op-input: a list of items
op-output: a list of unique items
op-parameter: ignored
@ -7,4 +9,6 @@ tags: [[Filter Operators]] [[Order Operators]] [[Listops Operators]]
title: unique Operator
type: text/vnd.tiddlywiki
<<.note """Unlike the default <<.link "Dominant Append" "Dominant Append">> handling of duplication, the effect of <<.op unique>> is to retain only the <<.em earliest>> instance among duplicated values.""">>
<<.operator-examples "unique">>