Thanks Eric, I appreciate that. I looked at it, but I really don’t know JavaScript. Makes me want to learn though.
On Sun, Jun 27, 2021 at 12:07 PM Eric Shulman <[email protected]> wrote: > On Sunday, June 27, 2021 at 11:28:50 AM UTC-7 History Buff wrote: > >> I don't understand why a 0 in the butlast operator would yield no results >> > > The butlast[] operator is defined in this shadow tiddler: > https://tiddlywiki.com/#%24%3A%2Fcore%2Fmodules%2Ffilters%2Flistops.js > > Here's the javascript code from that tiddler: > exports.butlast = function(source,operator,options) { > var count = $tw.utils.getInt(operator.operand,1), > results = []; > source(function(tiddler,title) { > results.push(title); > }); > return results.slice(0,-count); > }; > > The first line gets the operand value, defaulting to 1. > The next 4 lines copy the entire list of items into a results array > The last line uses the javascript slice() function to remove items from > the results array and then return that array > > Here's the documentation for the javascript slice() function: > > https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice > > Note the description of the "end" parameter: > Zero-based index before which to end extraction. slice extracts up to *but > not including* end. > > Thus, when you used butlast[0], the filter code invokes slice(0,-0), > i.e., "*starting from the first item up to but not including the first > item*" > which results in *no items* being returned. > > enjoy, > -e > > -- > You received this message because you are subscribed to a topic in the > Google Groups "TiddlyWiki" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/tiddlywiki/lROJc--2xFI/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/tiddlywiki/c1f40a73-746d-4c39-89b9-6786c9caee0fn%40googlegroups.com > <https://groups.google.com/d/msgid/tiddlywiki/c1f40a73-746d-4c39-89b9-6786c9caee0fn%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "TiddlyWiki" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/CAD1WRcZG21H%2BP2r73vLJZBua11QmkjaaL%3DrniecxwyraszarBA%40mail.gmail.com.
