[chaley]

Originally Posted by ackomb

So I've been fiddling with it some more, and figured out I can use the same principle as this

program:
	a = list_intersection($ao3tags, 'tram, train, bus, ferry', ',');
	list_union($#genre, a, ',')

but instead use 're' in the place of list-union

program:
        a = list_intersection($#show, 'Ferry, Bus', ',');
        re($#show, a , 'Vehicles, Public Transport')

The issue lies within the following, if a story has the following
tags: Bus, Car, Ferry, Ferry Terminal,
the result will be:
tags: Vehicles, Public Transport, Vehicles, Public Transport Terminal, Red, Car


The tag 'Ferry Terminal' will result in 'Public Transport Terminal'.
I figured the reason is because it is a match but not an exact match.
I've tried several options trying to get an exact match using ^ and $ like with regex but I keep getting errors

Can anyone point me in the right direction, because the Calibre Manual is not getting me anywhere on this one.

I am lost. What are you trying to do? Is this the problem you talked about 2 posts back where you want to replace any/all of 'tram, train, bus, ferry' by one instance of 'public transport'? If so, what is the list_intersection for? It returns a list that contains bus and/or ferry, if these two items exist in $#show. The order is not guaranteed.

Lets say you are trying to replace 'Ferry' or 'Starship' with 'Vehicle', and 'Bus' with 'Public Transport'. This does it.

program:
	sample_input = 'Bus, Car, Starship, Ferry, Ferry Terminal, Alien Spacecraft';

	output = list_re_group(
		sample_input, ',', '.',
		'(^bus$)|(^ferry$|^starship$)', 'Public Transport', 'Vehicle')

The output of the template is

Public Transport, Car, Vehicle, Ferry Terminal, Alien Spacecraft

There are other ways to do it, including processing the list with a 'for' statement then checking the items.

One thing to know: re() is nearly useless when dealing with lists. It doesn't deal with list order, instead treating the list as text. In certain situations such as my example above you can use list_re_group() so that the regular expression is applied to each list item, not the list itself.

If this discussion will go on for a while then it should get moved to its own thread. I can do that.