Template Function SEPARATORS - valid characters

[rdyornot]

In template functions that require a separator, what characters are valid?

I'm trying to get the first word of a field using sublist()
{series:sublist(0₁1,❓)}

I'd like to use a space, but it won't accept that, nor if I escape it, or use \s, put it in quotes... so - how can it be done, is there a way to separate with a space, or should I be using a different function (sublist seemed the most obvious)?

[ownedbycats]

Check out the template reference if you've not already.

[rdyornot]

I've looked through it several times, read through it and tried various searches - it never specifies valid characters for separators. It also doesn't seem to have come up in the forums before.

By the way - thanks to Ownedbycats and Capink for answering my previous question, without them I couldn't ask this next one!

[chaley]

Originally Posted by rdyornot

I've looked through it several times, read through it and tried various searches - it never specifies valid characters for separators. It also doesn't seem to have come up in the forums before.

The syntax of Single Function Mode, which you are using, is extremely basic. There is no such thing as a string. Spaces are not ignored. Commas are sometimes ignored. As the documentation says:

Important: If you have programming experience, please note that the syntax in Single Function Mode is not what you expect. Strings are not quoted and spaces are significant. All arguments are considered to be constants; there are no expressions.

You should use either Template Program Mode or General Program Mode. Both use a traditional syntax that separates strings from characters in the program. TPM's syntax is more constrained because it must live inside template snippets.

As for list separators, that is up to you. Any string can be used as a separator in the Template or General Program modes. Calibre uses both comma and ampersand, depending on the data. In some cases it uses a colon, for example in identifiers. You seem to want to split a space-separated phrase into words, which is possible in the more general modes but isn't something calibre does with its standard data types.

[rdyornot]

Originally Posted by chaley

The syntax of Single Function Mode, which you are using, is extremely basic. There is no such thing as a string. Spaces are not ignored. Commas are sometimes ignored. As the documentation says:

You should use either Template Program Mode or General Program Mode. Both use a traditional syntax that separates strings from characters in the program. TPM's syntax is more constrained because it must live inside template snippets.

As for list separators, that is up to you. Any string can be used as a separator in the Template or General Program modes. Calibre uses both comma and ampersand, depending on the data. In some cases it uses a colon, for example in identifiers. You seem to want to split a space-separated phrase into words, which is possible in the more general modes but isn't something calibre does with its standard data types.

Thank you - I was afraid of something like this. I'm trying to get the first one or two words from a book or series title - so i'm afraid as far as characters go anything but a space just won't work. If the function won't take a regex or escape character I'll just have to find some other work around.

I'm not much of a programmer, I'm mostly just making semi-educated guesses based on a couple of classes I took 20 years ago (C++ & tried to self teach Obc-C) so no experience with python. When I skimmed through the docs for Program modes I got the impression that it would probably take less time for me to just manually change the text of the books that are causing me problems than it would to learn to solve this programatically.

I thank everyone for their time & especially those who responded!

[davidfor]

Originally Posted by rdyornot

Thank you - I was afraid of something like this. I'm trying to get the first one or two words from a book or series title - so i'm afraid as far as characters go anything but a space just won't work. If the function won't take a regex or escape character I'll just have to find some other work around.

What you have is almost there. It is putting a space in place of the question mark:

{series:sublist(0,2, )}

That gets the first two words of the series. And to be clear, there is a space between the comma and the right parenthesis.

But, as @chaley mentioned, there are three modes. I don't like the above version. I would use General Program mode:

program:
sublist($series, 0, 2, " ")

I can read that and understand it, and there is no reliance on exact formatting of the template.

You could do this with regex:

program:
re($series, "^(.*? .*?\s).*", "\1")

Or maybe

program:
re($series, "^(.*?[\s:].*?[\s:]).*", "\1")

If you want to allow any white space or a colon as the separator. Which of the above is suitable depends on what it is you are trying to do.

[rdyornot]

Originally Posted by davidfor

What you have is almost there. It is putting a space in place of the question mark:

{series:sublist(0,2, )}

I would have sworn up and down that this was the first thing I tried. Thank you - now I need to go think about what I'm doing with my life.

[chaley]

Originally Posted by davidfor

What you have is almost there. It is putting a space in place of the question mark:

{series:sublist(0,2, )}

That gets the first two words of the series. And to be clear, there is a space between the comma and the right parenthesis.

This snippet in TPM also works.

{series:'sublist($, 0, 2,' ')'}

In TPM spaces aren't significant except in strings. TPM might be easier to use if the complete template has several {} sections.

But like @davidfor, I prefer GPM. They are easier to read and can be faster.