Section: User Contributed Perl Documentation (3)
Updated: 2021-01-27
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Text::BibTeX::Name - interface to BibTeX-style author names  


   use Text::BibTeX::Name;

   $name = Text::BibTeX::Name->new();
   $name->split('J. Random Hacker');
   # or:
   $name = Text::BibTeX::Name->new('J. Random Hacker');

   @firstname_tokens = $name->part ('first');
   $lastname = join (' ', $name->part ('last'));

   $format = Text::BibTeX::NameFormat->new();
   # ...customize $format...
   $formatted = $name->format ($format);



"Text::BibTeX::Name" provides an abstraction for BibTeX-style names and some basic operations on them. A name, in the BibTeX world, consists of a list of tokens which are divided amongst four parts: `first', `von', `last', and `jr'.

Tokens are separated by whitespace or commas at brace-level zero. Thus the name

   van der Graaf, Horace Q.

has five tokens, whereas the name

   {Foo, Bar, and Sons}

consists of a single token. Skip down to ``EXAMPLES'' for more examples, or read on if you want to know the exact details of how names are split into tokens and parts.

How tokens are divided into parts depends on the form of the name. If the name has no commas at brace-level zero (as in the second example), then it is assumed to be in either ``first last'' or ``first von last'' form. If there are no tokens that start with a lower-case letter, then ``first last'' form is assumed: the final token is the last name, and all other tokens form the first name. Otherwise, the earliest contiguous sequence of tokens with initial lower-case letters is taken as the `von' part; if this sequence includes the final token, then a warning is printed and the final token is forced to be the `last' part.

If a name has a single comma, then it is assumed to be in ``von last, first'' form. A leading sequence of tokens with initial lower-case letters, if any, forms the `von' part; tokens between the `von' and the comma form the `last' part; tokens following the comma form the `first' part. Again, if there are no tokens following a leading sequence of lowercase tokens, a warning is printed and the token immediately preceding the comma is taken to be the `last' part.

If a name has more than two commas, a warning is printed and the name is treated as though only the first two commas were present.

Finally, if a name has two commas, it is assumed to be in ``von last, jr, first'' form. (This is the only way to represent a name with a `jr' part.) The parsing of the name is the same as for a one-comma name, except that tokens between the two commas are taken to be the `jr' part.  


The C code that does the actual work of splitting up names takes a shortcut and makes few assumptions about whitespace. In particular, there must be no leading whitespace, no trailing whitespace, no consecutive whitespace characters in the string, and no whitespace characters other than space. In other words, all whitespace must consist of lone internal spaces.  


The strings "John Smith" and "Smith, John" are different representations of the same name, so split into parts and tokens the same way, namely as:

   first => ('John')
   von   => ()
   last  => ('Smith')
   jr    => ()

Note that every part is a list of tokens, even if there is only one token in that part; empty parts get empty token lists. Every token is just a string. Writing this example in actual code is simple:

   $name = Text::BibTeX::Name->new("John Smith");  # or "Smith, John"
   $name->part ('first');       # returns list ("John")
   $name->part ('last');        # returns list ("Smith")
   $name->part ('von');         # returns list ()
   $name->part ('jr');          # returns list ()

(We'll omit the empty parts in the rest of the examples: just assume that any unmentioned part is an empty list.) If more than two tokens are included and there's no comma, they'll go to the first name: thus "John Q. Smith" splits into

   first => ("John", "Q."))
   last  => ("Smith")

and "J. R. R. Tolkein" into

   first => ("J.", "R.", "R.")
   last  => ("Tolkein")

The ambiguous name "Kevin Philips Bong" splits into

   first => ("Kevin", "Philips")
   last  => ("Bong")

which may or may not be the right thing, depending on the particular person. There's no way to know though, so if this fellow's last name is ``Philips Bong'' and not ``Bong'', the string representation of his name must disambiguate. One possibility is "Philips Bong, Kevin" which splits into

   first => ("Kevin")
   last  => ("Philips", "Bong")

Alternately, "Kevin {Philips Bong}" takes advantage of the fact that tokes are only split on whitespace at brace-level zero, and becomes

   first => ("Kevin")
   last  => ("{Philips Bong}")

which is fine if your names are destined to be processed by TeX, but might be problematic in other contexts. Similarly, "St John-Mollusc, Oliver" becomes

   first => ("Oliver")
   last  => ("St", "John-Mollusc")

which can also be written as "Oliver {St John-Mollusc}":

   first => ("Oliver")
   last  => ("{St John-Mollusc}")

Since tokens are separated purely by whitespace, hyphenated names will work either way: both "Nigel Incubator-Jones" and "Incubator-Jones, Nigel" come out as

   first => ("Nigel")
   last  => ("Incubator-Jones")

Multi-token last names with lowercase components --- the ``von part'' --- work fine: both "Ludwig van Beethoven" and "van Beethoven, Ludwig" parse (correctly) into

   first => ("Ludwig")
   von   => ("van")
   last  => ("Beethoven")

This allows these European aristocratic names to sort properly, i.e. van Beethoven under B rather than v. Speaking of aristocratic European names, "Charles Louis Xavier Joseph de la Vall{\'e}e Poussin" is handled just fine, and splits into

   first => ("Charles", "Louis", "Xavier", "Joseph")
   von   => ("de", "la")
   last  => ("Vall{\'e}e", "Poussin")

so could be sorted under V rather than d. (Note that the sorting algorithm in Text::BibTeX::BibSort is a slavish imitiation of BibTeX 0.99, and therefore does the wrong thing with these names: the sort key starts with the ``von'' part.)

However, capitalized ``von parts'' don't work so well: "R. J. Van de Graaff" splits into

   first => ("R.", "J.", "Van")
   von   => ("de")
   last  => ("Graaff")

which is clearly wrong. This name should be represented as "Van de Graaff, R. J."

   first => ("R.", "J.")
   last  => ("Van", "de", "Graaff")

which is probably right. (This particular Van de Graaff was an American, so he probably belongs under V --- which is where my (British) dictionary puts him. Other Van de Graaff's mileages may vary.)

Finally, many names include a suffix: ``Jr.'', ``III'', ``fils'', and so forth. These are handled, but with some limitations. If there's a comma before the suffix (the usual U.S. convention for ``Jr.''), then the name should be in last, jr, first form, e.g. "Doe, Jr., John" comes out (correctly) as

   first => ("John")
   last  => ("Doe")
   jr    => ("Jr.")

but "John Doe, Jr." is ambiguous and is parsed as

   first => ("Jr.")
   last  => ("John", "Doe")

(so don't do it that way). If there's no comma before the suffix --- the usual for Roman numerals, and occasionally seen with ``Jr.'' --- then you're stuck and have to make the suffix part of the last name. Thus, "Gates III, William H." comes out

   first => ("William", "H.")
   last  => ("Gates", "III")

but "William H. Gates III" is ambiguous, and becomes

   first => ("William", "H.", "Gates")
   last  => ("III")

-- not what you want. Again, the curly-brace trick comes in handy, so "William H. {Gates III}" splits into

   first => ("William", "H.")
   last  => ("{Gates III}")

There is no way to make a comma-less suffix the "jr" part. (This is an unfortunate consequence of slavishly imitating BibTeX 0.99.)

Finally, names that aren't really names of people but rather are organization or company names should be forced into a single token by wrapping them in curly braces. For example, ``Foo, Bar and Sons'' should be written "{Foo, Bar and Sons}", which will split as

   last  => ("{Foo, Bar and Sons}")

Of course, if this is one name in a BibTeX "authors" or "editors" list, this name has to be wrapped in braces anyways (because of the " and "), but that's another story.  


Putting a split-up name back together again in a flexible, customizable way is the job of another module: see Text::BibTeX::NameFormat.  


Creates a new "Text::BibTeX::Name" object. If NAME is supplied, it must be a string containing a single name, and it will be be passed to the "split" method for further processing. FILENAME, LINE, and NAME_NUM, if present, are all also passed to "split" to allow better error messages.

If the first argument is a hash reference, it is used to define configuration values. At the moment the available values are:

Set the way Text::BibTeX deals with strings. By default it manages strings as bytes. You can set BINMODE to 'utf-8' to get NFC normalized UTF-8 strings and you can customise the normalization with the NORMALIZATION option.

      { binmode => 'utf-8', normalization => 'NFD' },
      "Alberto Simo~es"});

Splits NAME (a string containing a single name) into tokens and subsequently into the four parts of a BibTeX-style name (first, von, last, and jr). (Each part is a list of tokens, and tokens are separated by whitespace or commas at brace-depth zero. See above for full details on how a name is split into its component parts.)

The token-lists that make up each part of the name are then stored in the "Text::BibTeX::Name" object for later retrieval or formatting with the "part" and "format" methods.

Returns the list of tokens in part PARTNAME of a name previously split with "split". For example, suppose a "Text::BibTeX::Name" object is created and initialized like this:

   $name = Text::BibTeX::Name->new();
   $name->split ('Charles Louis Xavier Joseph de la Vall{\'e}e Poussin');

Then this code:

   $name->part ('von');

would return the list "('de','la')".

format (FORMAT)
Formats a name according to the specifications encoded in FORMAT, which should be a "Text::BibTeX::NameFormat" (or descendant) object. (In short, it must supply a method "apply" which takes a "Text::BibTeX::NameFormat" object as its only argument.) Returns the formatted name as a string.

See Text::BibTeX::NameFormat for full details on formatting names.



Text::BibTeX::Entry, Text::BibTeX::NameFormat, bt_split_names.  


Greg Ward <gward@python.net>  


Copyright (c) 1997-2000 by Gregory P. Ward. All rights reserved. This file is part of the Text::BibTeX library. This library is free software; you may redistribute it and/or modify it under the same terms as Perl itself.