created: 20140410103123179
modified: 20150124164957000
tags: [[Filter Operators]] [[Group Operators]]
title: each Operator
type: text/vnd.tiddlywiki
caption: each
purpose: select one of each group of input titles by field

<$macrocall $name=".operator-def"
input="a [[selection of titles|Title Selection]]"
parameter="the name of a [[field|TiddlerFields]]"
paramName="f"
output="a selection containing the first input title encountered for each distinct value of field <<.place f>>"
/>

Each input title is processed in turn. The value of field <<.place f>> in the corresponding tiddler is examined, and as long as the value has not been encountered before, the title is appended to the output set.

If a tiddler doesn't contain field <<.place f>>, or contains it but with an empty value, then it contributes nothing to the output.

<<.operator-examples "each">>