NAME
patgen - generate patterns for TeX hyphenation
SYNOPSIS
patgen dictionary_file pattern_file patout_file translate_file
DESCRIPTION
This manual page is not meant to be exhaustive. See also the Info file
or manual Web2C: A TeX implementation.
The patgen program reads the dictionary_file containing a list of
hyphenated words and the pattern_file containing previously-generated
patterns (if any) for a particular language (not a complete TeX source
file; see below), and produces the patout_file with (previously- plus
newly-generated) hyphenation patterns for that language. The
translate_file defines language specific values for the parameters
left_hyphen_min and right_hyphen_min used by TeX's hyphenation
algorithm and the external representation of the lower and upper case
version(s) of all `letters' of that language. Further details of the
pattern generation process such as hyphenation levels and pattern
lengths are requested interactively from the user's terminal.
Optionally patgen creates a new dictionary file pattmp.n showing the
good and bad hyphens found by the generated patterns, where n is the
highest hyphenation level.
The patterns generated by patgen can be read by initex for use in
hyphenating words. For a real-life example of patgen's output, see
$TEXMFMAIN/tex/generic/hyphen/hyphen.tex, which contains the patterns
TeX uses for English by default. At some sites, patterns for (many)
other languages may be available, and the local tex programs may have
them preloaded.
All filenames must be complete; no adding of default extensions or path
searching is done.
FILE FORMATS
Letters
When initex digests hyphenation patterns, TeX first expands macros
and the result must entirely consist of digits (hyphenation
levels), dots (`.', edge of a word), and letters. In pattern files
for non-English languages letters are often represented by macros
or other expandable constructs. For the purpose of patgen these
are just character sequences, subject to the condition that no such
sequence is a prefix of another one.
Dictionary file
A dictionary file contains a weighted list of hyphenated words, one
word per line starting in column 1. A digit in column 1 indicates a
global word weight (initially =1) applicable to all following words
up to the next global word weight. A digit at some intercharacter
position indicates a weight for that position only.
The hyphens in a word are indicated by `-', `*', or `.' (or their
replacements as defined in the translate file) for hyphens yet to
be found, `good' hyphens (correctly found by the patterns), and
`bad' hyphens (erroneously found by the patterns) respectively;
when reading a dictionary file `*' is treated like `-' and `.' is
ignored.
Pattern file
A pattern file contains only patterns in the format above, e.g.,
from a previous run of patgen. It may not contain any TeX comments
or control sequences. For instance, this is not a valid pattern
file:
% this is a pattern file read by TeX.
\patterns{%
...
}
It can only contain the actual patterns, i.e., the `...'.
Translate file
A translate file starts with a line containing the values of
left_hyphen_min in columns 1-2, right_hyphen_min in columns 3-4,
and either a blank or the replacement for one of the "hyphen"
characters `-', `*', and `.' in columns 5, 6, and 7. (Input lines
are padded with blanks as for many TeX related programs.)
Each following line defines one `letter': an arbitrary delimiter
character in column 1, followed by one or more external
representations of that character (first the `lower' case one used
for output), each one terminated by the delimiter and the whole
sequence terminated by another delimiter.
If the translate file is empty, the values left_hyphen_min=2,
right_hyphen_min=3, and the 26 lower case letters a...z with their
upper case representations A...Z are assumed.
Terminal input
After reading the translate_file and any previously-generated
patterns from pattern_file, patgen requests input from the user's
terminal.
First the integer values of hyph_start and hyph_finish, the lowest
and highest hyphenation level for which patterns are to be
generated. The value of hyph_start should be larger than any
hyphenation level already present in pattern_file.
Then, for each hyphenation level, the integer values of pat_start
and pat_finish, the smallest and largest pattern length to be
analyzed, as well as good weight, bad weight, and threshold, the
weights for good and bad hyphens and a weight threshold for useful
patterns.
Finally the decision (`y' or `Y' vs. anything else) whether or not
to produce a hyphenated word list.
FILES
$TEXMFMAIN/tex/generic/hyphen/hyphen.tex
The original hyphenation patterns for English, by Donald Knuth and
Frank Liang.
$TEXMFMAIN/tex/generic/hyphen/ushyphmax.tex
Maximal hyphenation patterns for English, extended by Gerard
Kuiken.
http://www.ctan.org/tex-archive/language/
Patterns and support for many other languages
SEE ALSO
Frank Liang and Peter Breitenlohner, patgen.web.
Frank Liang, Word hy-phen-a-tion by com-puter, STAN-CS-83-977, Stanford
University Ph.D. thesis, 1983, http://tug.org/docs/liang.
Donald E. Knuth, The TeXbook, Addison-Wesley, 1986, ISBN 0-201-13447-0,
Appendix H.
AUTHORS
Frank Liang wrote the first version of this program. Peter
Breitenlohner made a substantial revision in 1991 for TeX 3. The first
version was published as the appendix to the TeXware technical report.
Howard Trickey originally ported it to Unix.