Provided by: libhunspell-dev_1.7.2+really1.7.1-2_amd64 
NAME
hunspell - format of Hunspell dictionaries and affix files
DESCRIPTION
Hunspell(1) Hunspell requires two files to define the way a language is being spell
checked: a dictionary file containing words and applicable flags, and an affix file that
specifies how these flags will control spell checking. An optional file is the personal
dictionary file.
Dictionary file
A dictionary file (*.dic) contains a list of words, one per line. The first line of the
dictionaries (except personal dictionaries) contains the approximate word count (for
optimal hash memory size). Each word may optionally be followed by a slash ("/") and one
or more flags, which represents the word attributes, for example affixes.
Note: Dictionary words can contain also slashes when escaped like "\/" syntax.
It's worth to add not only words, but word pairs to the dictionary to get correct
suggestions for common misspellings with missing space, as in the following example, for
the bad "alot" and "inspite" (see also "REP" and field "ph:" about correct suggestions for
common misspellings):
3
word
a lot
in spite
Personal dictionary file
Personal dictionaries are simple word lists. Asterisk at the first character position
signs prohibition. A second word separated by a slash sets the affixation.
foo
Foo/Simpson
*bar
In this example, "foo" and "Foo" are personal words, plus Foo will be recognized with
affixes of Simpson (Foo's etc.) and bar is a forbidden word.
Short example
Dictionary file:
3
hello
try/B
work/AB
The flags B and A specify attributes of these words.
Affix file:
SET UTF-8
TRY esianrtolcdugmphbyfvkwzESIANRTOLCDUGMPHBYFVKWZ'
REP 2
REP f ph
REP ph f
PFX A Y 1
PFX A 0 re .
SFX B Y 2
SFX B 0 ed [^y]
SFX B y ied y
In the affix file, prefix A and suffix B have been defined. Flag A defines a `re-'
prefix. Class B defines two `-ed' suffixes. First B suffix can be added to a word if the
last character of the word isn't `y'. Second suffix can be added to the words terminated
with an `y'.
All accepted words with this dictionary and affix combination are: "hello", "try",
"tried", "work", "worked", "rework", "reworked".
AFFIX FILE GENERAL OPTIONS
Hunspell source distribution contains more than 80 examples for option usage.
SET encoding
Set character encoding of words and morphemes in affix and dictionary files.
Possible values: UTF-8, ISO8859-1 - ISO8859-10, ISO8859-13 - ISO8859-15, KOI8-R,
KOI8-U, cp1251, ISCII-DEVANAGARI.
SET UTF-8
FLAG value
Set flag type. Default type is the extended ASCII (8-bit) character. `UTF-8'
parameter sets UTF-8 encoded Unicode character flags. The `long' value sets the
double extended ASCII character flag type, the `num' sets the decimal number flag
type. Decimal flags numbered from 1 to 65000, and in flag fields are separated by
comma. BUG: UTF-8 flag type doesn't work on ARM platform.
FLAG long
COMPLEXPREFIXES
Set twofold prefix stripping (but single suffix stripping) eg. for morphologically
complex languages with right-to-left writing system.
LANG langcode
Set language code for language-specific functions of Hunspell. Use it to activate
special casing of Azeri (LANG az), Turkish (LANG tr) and Crimean Tatar (LANG crh),
also not generalized syllable-counting compounding rules of Hungarian (LANG hu).
IGNORE characters
Sets characters to ignore dictionary words, affixes and input words. Useful for
optional characters, as Arabic (harakat) or Hebrew (niqqud) diacritical marks (see
tests/ignore.* test dictionary in Hunspell distribution).
AF number_of_flag_vector_aliases
AF flag_vector
Hunspell can substitute affix flag sets with ordinal numbers in affix rules (alias
compression, see makealias tool). First example with alias compression:
3
hello
try/1
work/2
AF definitions in the affix file:
AF 2
AF A
AF AB
It is equivalent of the following dic file:
3
hello
try/A
work/AB
See also tests/alias* examples of the source distribution.
Note I: If affix file contains the FLAG parameter, define it before the AF definitions.
Note II: Use makealias utility in Hunspell distribution to compress aff and dic files.
AM number_of_morphological_aliases
AM morphological_fields
Hunspell can substitute also morphological data with ordinal numbers in affix rules
(alias compression). See tests/alias* examples.
AFFIX FILE OPTIONS FOR SUGGESTION
Suggestion parameters can optimize the default n-gram (similarity search in the dictionary
words based on the common 1, 2, 3, 4-character length common character-sequences),
character swap and deletion suggestions of Hunspell. REP is suggested to fix the typical
and especially bad language specific bugs, because the REP suggestions have the highest
priority in the suggestion list. PHONE is for languages with not pronunciation based
orthography.
For short common misspellings, it's important to use the ph: field (see later) to give the
best suggestions.
KEY characters_separated_by_vertical_line_optionally
Hunspell searches and suggests words with one different character replaced by a
neighbor KEY character. Not neighbor characters in KEY string separated by vertical
line characters. Suggested KEY parameters for QWERTY and Dvorak keyboard layouts:
KEY qwertyuiop|asdfghjkl|zxcvbnm
KEY pyfgcrl|aeouidhtns|qjkxbmwvz
Using the first QWERTY layout, Hunspell suggests "nude" and "node" for "*nide". A
character may have more neighbors, too:
KEY qwertzuop|yxcvbnm|qaw|say|wse|dsx|sy|edr|fdc|dx|rft|gfv|fc|tgz|hgb|gv|zhu|jhn|hb|uji|kjm|jn|iko|lkm
TRY characters
Hunspell can suggest right word forms, when they differ from the bad input word by
one TRY character. The parameter of TRY is case sensitive.
NOSUGGEST flag
Words signed with NOSUGGEST flag are not suggested (but still accepted when typed
correctly). Proposed flag for vulgar and obscene words (see also SUBSTANDARD).
MAXCPDSUGS num
Set max. number of suggested compound words generated by compound rules. The number
of the suggested compound words may be greater from the same 1-character distance
type.
MAXNGRAMSUGS num
Set max. number of n-gram suggestions. Value 0 switches off the n-gram suggestions
(see also MAXDIFF).
MAXDIFF [0-10]
Set the similarity factor for the n-gram based suggestions (5 = default value; 0 =
fewer n-gram suggestions, but min. 1; 10 = MAXNGRAMSUGS n-gram suggestions).
ONLYMAXDIFF
Remove all bad n-gram suggestions (default mode keeps one, see MAXDIFF).
NOSPLITSUGS
Disable word suggestions with spaces.
SUGSWITHDOTS
Add dot(s) to suggestions, if input word terminates in dot(s). (Not for
LibreOffice dictionaries, because LibreOffice has an automatic dot expansion
mechanism.)
REP number_of_replacement_definitions
REP what replacement
This table specifies modifications to try first. First REP is the header of this
table and one or more REP data line are following it. With this table, Hunspell
can suggest the right forms for the typical spelling mistakes when the incorrect
form differs by more than 1 letter from the right form (see also "ph:"). The
search string supports the regex boundary signs (^ and $). For example a possible
English replacement table definition to handle misspelled consonants:
REP 5
REP f ph
REP ph f
REP tion$ shun
REP ^cooccurr co-occurr
REP ^alot$ a_lot
Note I: It's very useful to define replacements for the most typical one-character
mistakes, too: with REP you can add higher priority to a subset of the TRY suggestions
(suggestion list begins with the REP suggestions).
Note II: Suggesting separated words, specify spaces with underlines:
REP 1
REP onetwothree one_two_three
Note III: Replacement table can be used for a stricter compound word checking with the
option CHECKCOMPOUNDREP.
MAP number_of_map_definitions
MAP string_of_related_chars_or_parenthesized_character_sequences
We can define language-dependent information on characters and character sequences
that should be considered related (i.e. nearer than other chars not in the set) in
the affix file (.aff) by a map table. With this table, Hunspell can suggest the
right forms for words, which incorrectly choose the wrong letter or letter groups
from a related set more than once in a word (see REP).
For example a possible mapping could be for the German umlauted ü versus the
regular u; the word Frühstück really should be written with umlauted u's and not
regular ones
MAP 1
MAP uü
Use parenthesized groups for character sequences (eg. for composed Unicode characters):
MAP 3
MAP ß(ss) (character sequence)
MAP fi(fi) ("fi" compatibility characters for Unicode fi ligature)
MAP (ọ́)o (composed Unicode character: ó with bottom dot)
PHONE number_of_phone_definitions
PHONE what replacement
PHONE uses a table-driven phonetic transcription algorithm borrowed from Aspell. It
is useful for languages with not pronunciation based orthography. You can add a
full alphabet conversion and other rules for conversion of special letter
sequences. For detailed documentation see http://aspell.net/man-html/Phonetic-
Code.html. Note: Multibyte UTF-8 characters have not worked with bracket
expression yet. Dash expression has signed bytes and not UTF-8 characters yet.
WARN flag
This flag is for rare words, which are also often spelling mistakes, see option -r
of command line Hunspell and FORBIDWARN.
FORBIDWARN
Words with flag WARN aren't accepted by the spell checker using this parameter.
OPTIONS FOR COMPOUNDING
BREAK number_of_break_definitions
BREAK character_or_character_sequence
Define new break points for breaking words and checking word parts separately. Use
^ and $ to delete characters at end and start of the word. Rationale: useful for
compounding with joining character or strings (for example, hyphen in English and
German or hyphen and n-dash in Hungarian). Dashes are often bad break points for
tokenization, because compounds with dashes may contain not valid parts, too.)
With BREAK, Hunspell can check both side of these compounds, breaking the words at
dashes and n-dashes:
BREAK 2
BREAK -
BREAK -- # n-dash
Breaking are recursive, so foo-bar, bar-foo and foo-foo--bar-bar would be valid compounds.
Note: The default word break of Hunspell is equivalent of the following BREAK definition:
BREAK 3
BREAK -
BREAK ^-
BREAK -$
Hunspell doesn't accept the "-word" and "word-" forms by this BREAK definition:
BREAK 1
BREAK -
Switching off the default values:
BREAK 0
Note II: COMPOUNDRULE is better for handling dashes and other compound joining characters
or character strings. Use BREAK, if you want to check words with dashes or other joining
characters and there is no time or possibility to describe precise compound rules with
COMPOUNDRULE (COMPOUNDRULE handles only the suffixation of the last word part of a
compound word).
Note III: For command line spell checking of words with extra characters, set WORDCHARS
parameters: WORDCHARS --- (see tests/break.*) example
COMPOUNDRULE number_of_compound_definitions
COMPOUNDRULE compound_pattern
Define custom compound patterns with a regex-like syntax. The first COMPOUNDRULE
is a header with the number of the following COMPOUNDRULE definitions. Compound
patterns consist compound flags, parentheses, star and question mark meta
characters. A flag followed by a `*' matches a word sequence of 0 or more matches
of words signed with this compound flag. A flag followed by a `?' matches a word
sequence of 0 or 1 matches of a word signed with this compound flag. See
tests/compound*.* examples.
Note: en_US dictionary of OpenOffice.org uses COMPOUNDRULE for ordinal number
recognition (1st, 2nd, 11th, 12th, 22nd, 112th, 1000122nd etc.).
Note II: In the case of long and numerical flag types use only parenthesized flags:
(1500)*(2000)?
Note III: COMPOUNDRULE flags work completely separately from the compounding
mechanisms using COMPOUNDFLAG, COMPOUNDBEGIN, etc. compound flags. (Use these flags
on different entries for words).
COMPOUNDMIN num
Minimum length of words used for compounding. Default value is 3 letters.
COMPOUNDFLAG flag
Words signed with COMPOUNDFLAG may be in compound words (except when word shorter
than COMPOUNDMIN). Affixes with COMPOUNDFLAG also permits compounding of affixed
words.
COMPOUNDBEGIN flag
Words signed with COMPOUNDBEGIN (or with a signed affix) may be first elements in
compound words.
COMPOUNDLAST flag
Words signed with COMPOUNDLAST (or with a signed affix) may be last elements in
compound words.
COMPOUNDMIDDLE flag
Words signed with COMPOUNDMIDDLE (or with a signed affix) may be middle elements in
compound words.
ONLYINCOMPOUND flag
Suffixes signed with ONLYINCOMPOUND flag may be only inside of compounds (Fuge-
elements in German, fogemorphemes in Swedish). ONLYINCOMPOUND flag works also with
words (see tests/onlyincompound.*). Note: also valuable to flag compounding parts
which are not correct as a word by itself.
COMPOUNDPERMITFLAG flag
Prefixes are allowed at the beginning of compounds, suffixes are allowed at the end
of compounds by default. Affixes with COMPOUNDPERMITFLAG may be inside of
compounds.
COMPOUNDFORBIDFLAG flag
Suffixes with this flag forbid compounding of the affixed word. Dictionary words
with this flag are removed from the beginning and middle of compound words,
overriding the effect of COMPOUNDPERMITFLAG.
COMPOUNDMORESUFFIXES
Allow twofold suffixes within compounds.
COMPOUNDROOT flag
COMPOUNDROOT flag signs the compounds in the dictionary (Now it is used only in the
Hungarian language specific code).
COMPOUNDWORDMAX number
Set maximum word count in a compound word. (Default is unlimited.)
CHECKCOMPOUNDDUP
Forbid word duplication in compounds (e.g. foofoo).
CHECKCOMPOUNDREP
Forbid compounding, if the (usually bad) compound word may be a non-compound word
with a REP fault. Useful for languages with `compound friendly' orthography.
CHECKCOMPOUNDCASE
Forbid upper case characters at word boundaries in compounds.
CHECKCOMPOUNDTRIPLE
Forbid compounding, if compound word contains triple repeating letters (e.g. foo|ox
or xo|oof). Bug: missing multi-byte character support in UTF-8 encoding (works only
for 7-bit ASCII characters).
SIMPLIFIEDTRIPLE
Allow simplified 2-letter forms of the compounds forbidden by CHECKCOMPOUNDTRIPLE.
It's useful for Swedish and Norwegian (and for the old German orthography:
Schiff|fahrt -> Schiffahrt).
CHECKCOMPOUNDPATTERN number_of_checkcompoundpattern_definitions
CHECKCOMPOUNDPATTERN endchars[/flag] beginchars[/flag] [replacement]
Forbid compounding, if the first word in the compound ends with endchars, and next
word begins with beginchars and (optionally) they have the requested flags. The
optional replacement parameter allows simplified compound form.
The special "endchars" pattern 0 (zero) limits the rule to the unmodified stems
(stems and stems with zero affixes):
CHECKCOMPOUNDPATTERN 0/x /y
Note: COMPOUNDMIN doesn't work correctly with the compound word alternation, so it may
need to set COMPOUNDMIN to lower value.
FORCEUCASE flag
Last word part of a compound with flag FORCEUCASE forces capitalization of the
whole compound word. Eg. Dutch word "straat" (street) with FORCEUCASE flags will
allowed only in capitalized compound forms, according to the Dutch spelling rules
for proper names.
COMPOUNDSYLLABLE max_syllable vowels
Need for special compounding rules in Hungarian. First parameter is the maximum
syllable number, that may be in a compound, if words in compounds are more than
COMPOUNDWORDMAX. Second parameter is the list of vowels (for calculating
syllables).
SYLLABLENUM flags
Need for special compounding rules in Hungarian.
AFFIX FILE OPTIONS FOR AFFIX CREATION
PFX flag cross_product number
PFX flag stripping prefix [condition [morphological_fields...]]
SFX flag cross_product number
SFX flag stripping suffix [condition [morphological_fields...]]
An affix is either a prefix or a suffix attached to root words to make other words.
We can define affix classes with arbitrary number affix rules. Affix classes are
signed with affix flags. The first line of an affix class definition is the header.
The fields of an affix class header:
(0) Option name (PFX or SFX)
(1) Flag (name of the affix class)
(2) Cross product (permission to combine prefixes and suffixes). Possible values:
Y (yes) or N (no)
(3) Line count of the following rules.
Fields of an affix rules:
(0) Option name
(1) Flag
(2) stripping characters from beginning (at prefix rules) or end (at suffix rules)
of the word
(3) affix (optionally with flags of continuation classes, separated by a slash)
(4) condition.
Zero stripping or affix are indicated by zero. Zero condition is indicated by dot.
Condition is a simplified, regular expression-like pattern, which must be met
before the affix can be applied. (Dot signs an arbitrary character. Characters in
braces sign an arbitrary character from the character subset. Dash hasn't got
special meaning, but circumflex (^) next the first brace sets the complementer
character set.)
(5) Optional morphological fields separated by spaces or tabulators.
AFFIX FILE OTHER OPTIONS
CIRCUMFIX flag
Affixes signed with CIRCUMFIX flag may be on a word when this word also has a
prefix with CIRCUMFIX flag and vice versa (see circumfix.* test files in the source
distribution).
FORBIDDENWORD flag
This flag signs forbidden word form. Because affixed forms are also forbidden, we
can subtract a subset from set of the accepted affixed and compound words. Note:
usefull to forbid erroneous words, generated by the compounding mechanism.
FULLSTRIP
With FULLSTRIP, affix rules can strip full words, not only one less characters,
before adding the affixes, see fullstrip.* test files in the source distribution).
Note: conditions may be word length without FULLSTRIP, too.
KEEPCASE flag
Forbid uppercased and capitalized forms of words signed with KEEPCASE flags. Useful
for special orthographies (measurements and currency often keep their case in
uppercased texts) and writing systems (e.g. keeping lower case of IPA characters).
Also valuable for words erroneously written in the wrong case.
Note: With CHECKSHARPS declaration, words with sharp s and KEEPCASE flag may be
capitalized and uppercased, but uppercased forms of these words may not contain
sharp s, only SS. See germancompounding example in the tests directory of the
Hunspell distribution.
ICONV number_of_ICONV_definitions
ICONV pattern pattern2
Define input conversion table. Note: useful to convert one type of quote to
another one, or change ligature.
OCONV number_of_OCONV_definitions
OCONV pattern pattern2
Define output conversion table.
LEMMA_PRESENT flag
Deprecated. Use "st:" field instead of LEMMA_PRESENT.
NEEDAFFIX flag
This flag signs virtual stems in the dictionary, words only valid when affixed.
Except, if the dictionary word has a homonym or a zero affix. NEEDAFFIX works also
with prefixes and prefix + suffix combinations (see tests/needaffix5.*).
PSEUDOROOT flag
Deprecated. (Former name of the NEEDAFFIX option.)
SUBSTANDARD flag
SUBSTANDARD flag signs affix rules and dictionary words (allomorphs) not used in
morphological generation and root words removed from suggestion. See also
NOSUGGEST.
WORDCHARS characters
WORDCHARS extends tokenizer of Hunspell command line interface with additional word
character. For example, dot, dash, n-dash, numbers, percent sign are word character
in Hungarian.
CHECKSHARPS
SS letter pair in uppercased (German) words may be upper case sharp s (ß).
Hunspell can handle this special casing with the CHECKSHARPS declaration (see also
KEEPCASE flag and tests/germancompounding example) in both spelling and suggestion.
Morphological analysis
Hunspell's dictionary items and affix rules may have optional space or tabulator separated
morphological description fields, started with 3-character (two letters and a colon) field
IDs:
word/flags po:noun is:nom
Example: We define a simple resource with morphological informations, a derivative suffix
(ds:) and a part of speech category (po:):
Affix file:
SFX X Y 1
SFX X 0 able . ds:able
Dictionary file:
drink/X po:verb
Test file:
drink
drinkable
Test:
$ analyze test.aff test.dic test.txt
> drink
analyze(drink) = po:verb
stem(drink) = po:verb
> drinkable
analyze(drinkable) = po:verb ds:able
stem(drinkable) = drinkable
You can see in the example, that the analyzer concatenates the morphological fields in
item and arrangement style.
Optional data fields
Default morphological and other IDs (used in suggestion, stemming and morphological
generation):
ph: Alternative transliteration for better suggestions, ie. misspellings related to
the special orthography and pronunciation of the word. The best way to handle
common misspellings, so it's worth to add ph: field to the most affected few
thousand dictionary words (or word pairs etc.) to get correct suggestions for their
misspellings.
For example:
Wednesday ph:wendsay ph:wensday
Marseille ph:maarsayl
Hunspell adds all ph: transliterations to the inner REP table, so it will always suggest
the correct word for the specified misspellings with the highest priority.
The previous example is equivalent of the following REP definition:
REP 6
REP wendsay Wednesday
REP Wendsay Wednesday
REP wensday Wednesday
REP Wensday Wednesday
REP maarsayl Marseille
REP Maarsayl Marseille
The asterisk at the end of the ph: pattern means stripping the terminating character both
from the pattern and the word in the associated REP rule:
pretty ph:prity*
will result
REP 1
REP prit prett
REP rule, resulting the following correct suggestions
*prity -> pretty
*pritier -> prettier
*pritiest -> prettiest
Moreover, ph: fields can handle suggestions with more than two words, also different
suggestions for the same misspelling:
do not know ph:dunno
don't know ph:dunno
results
*dunno -> do not know, don't know
Note: if available, ph: is used in n-gram similarity, too.
The ASCII arrow "->" in a ph: pattern means a REP rule (see REP), creating arbitrary
replacement rule associated to the dictionary item:
happy/B ph:hepy ph:hepi->happi
results
*hepy -> happy
*hepiest -> happiest
st: Stem. Optional: default stem is the dictionary item in morphological analysis. Stem
field is useful for virtual stems (dictionary words with NEEDAFFIX flag) and
morphological exceptions instead of new, single used morphological rules.
feet st:foot is:plural
mice st:mouse is:plural
teeth st:tooth is:plural
Word forms with multiple stems need multiple dictionary items:
lay po:verb st:lie is:past_2
lay po:verb is:present
lay po:noun
al: Allomorph(s). A dictionary item is the stem of its allomorphs. Morphological
generation needs stem, allomorph and affix fields.
sing al:sang al:sung
sang st:sing
sung st:sing
po: Part of speech category.
ds: Derivational suffix(es). Stemming doesn't remove derivational suffixes.
Morphological generation depends on the order of the suffix fields.
In affix rules:
SFX Y Y 1
SFX Y 0 ly . ds:ly_adj
In the dictionary:
ably st:able ds:ly_adj
able al:ably
is: Inflectional suffix(es). All inflectional suffixes are removed by stemming.
Morphological generation depends on the order of the suffix fields.
feet st:foot is:plural
ts: Terminal suffix(es). Terminal suffix fields are inflectional suffix fields
"removed" by additional (not terminal) suffixes.
Useful for zero morphemes and affixes removed by splitting rules.
work/D ts:present
SFX D Y 2
SFX D 0 ed . is:past_1
SFX D 0 ed . is:past_2
Typical example of the terminal suffix is the zero morpheme of the nominative case.
sp: Surface prefix. Temporary solution for adding prefixes to the stems and generated
word forms. See tests/morph.* example.
pa: Parts of the compound words. Output fields of morphological analysis for stemming.
dp: Planned: derivational prefix.
ip: Planned: inflectional prefix.
tp: Planned: terminal prefix.
Twofold suffix stripping
Ispell's original algorithm strips only one suffix. Hunspell can strip another one yet (or
a plus prefix in COMPLEXPREFIXES mode).
The twofold suffix stripping is a significant improvement in handling of immense number of
suffixes, that characterize agglutinative languages.
A second `s' suffix (affix class Y) will be the continuation class of the suffix `able' in
the following example:
SFX Y Y 1
SFX Y 0 s .
SFX X Y 1
SFX X 0 able/Y .
Dictionary file:
drink/X
Test file:
drink
drinkable
drinkables
Test:
$ hunspell -m -d test <test.txt
drink st:drink
drinkable st:drink fl:X
drinkables st:drink fl:X fl:Y
Theoretically with the twofold suffix stripping needs only the square root of the number
of suffix rules, compared with a Hunspell implementation. In our practice, we could have
elaborated the Hungarian inflectional morphology with twofold suffix stripping.
Extended affix classes
Hunspell can handle more than 65000 affix classes. There are three new syntax for giving
flags in affix and dictionary files.
FLAG long command sets 2-character flags:
FLAG long
SFX Y1 Y 1
SFX Y1 0 s 1
Dictionary record with the Y1, Z3, F? flags:
foo/Y1Z3F?
FLAG num command sets numerical flags separated by comma:
FLAG num
SFX 65000 Y 1
SFX 65000 0 s 1
Dictionary example:
foo/65000,12,2756
The third one is the Unicode character flags.
Homonyms
Hunspell's dictionary can contain repeating elements that are homonyms:
work/A po:verb
work/B po:noun
An affix file:
SFX A Y 1
SFX A 0 s . sf:sg3
SFX B Y 1
SFX B 0 s . is:plur
Test file:
works
Test:
$ hunspell -d test -m <testwords
work st:work po:verb is:sg3
work st:work po:noun is:plur
This feature also gives a way to forbid illegal prefix/suffix combinations.
Prefix--suffix dependencies
An interesting side-effect of multi-step stripping is, that the appropriate treatment of
circumfixes now comes for free. For instance, in Hungarian, superlatives are formed by
simultaneous prefixation of leg- and suffixation of -bb to the adjective base. A problem
with the one-level architecture is that there is no way to render lexical licensing of
particular prefixes and suffixes interdependent, and therefore incorrect forms are
recognized as valid, i.e. *legvén = leg + vén `old'. Until the introduction of clusters, a
special treatment of the superlative had to be hardwired in the earlier HunSpell code.
This may have been legitimate for a single case, but in fact prefix--suffix dependences
are ubiquitous in category-changing derivational patterns (cf. English payable, non-
payable but *non-pay or drinkable, undrinkable but *undrink). In simple words, here, the
prefix un- is legitimate only if the base drink is suffixed with -able. If both these
patters are handled by on-line affix rules and affix rules are checked against the base
only, there is no way to express this dependency and the system will necessarily over- or
undergenerate.
In next example, suffix class R have got a prefix `continuation' class (class P).
PFX P Y 1
PFX P 0 un . [prefix_un]+
SFX S Y 1
SFX S 0 s . +PL
SFX Q Y 1
SFX Q 0 s . +3SGV
SFX R Y 1
SFX R 0 able/PS . +DER_V_ADJ_ABLE
Dictionary:
2
drink/RQ [verb]
drink/S [noun]
Morphological analysis:
> drink
drink[verb]
drink[noun]
> drinks
drink[verb]+3SGV
drink[noun]+PL
> drinkable
drink[verb]+DER_V_ADJ_ABLE
> drinkables
drink[verb]+DER_V_ADJ_ABLE+PL
> undrinkable
[prefix_un]+drink[verb]+DER_V_ADJ_ABLE
> undrinkables
[prefix_un]+drink[verb]+DER_V_ADJ_ABLE+PL
> undrink
Unknown word.
> undrinks
Unknown word.
Circumfix
Conditional affixes implemented by a continuation class are not enough for circumfixes,
because a circumfix is one affix in morphology. We also need CIRCUMFIX option for correct
morphological analysis.
# circumfixes: ~ obligate prefix/suffix combinations
# superlative in Hungarian: leg- (prefix) AND -bb (suffix)
# nagy, nagyobb, legnagyobb, legeslegnagyobb
# (great, greater, greatest, most greatest)
CIRCUMFIX X
PFX A Y 1
PFX A 0 leg/X .
PFX B Y 1
PFX B 0 legesleg/X .
SFX C Y 3
SFX C 0 obb . +COMPARATIVE
SFX C 0 obb/AX . +SUPERLATIVE
SFX C 0 obb/BX . +SUPERSUPERLATIVE
Dictionary:
1
nagy/C [MN]
Analysis:
> nagy
nagy[MN]
> nagyobb
nagy[MN]+COMPARATIVE
> legnagyobb
nagy[MN]+SUPERLATIVE
> legeslegnagyobb
nagy[MN]+SUPERSUPERLATIVE
Compounds
Allowing free compounding yields decrease in precision of recognition, not to mention
stemming and morphological analysis. Although lexical switches are introduced to license
compounding of bases by Ispell, this proves not to be restrictive enough. For example:
# affix file
COMPOUNDFLAG X
2
foo/X
bar/X
With this resource, foobar and barfoo also are accepted words.
This has been improved upon with the introduction of direction-sensitive compounding,
i.e., lexical features can specify separately whether a base can occur as leftmost or
rightmost constituent in compounds. This, however, is still insufficient to handle the
intricate patterns of compounding, not to mention idiosyncratic (and language specific)
norms of hyphenation.
The Hunspell algorithm currently allows any affixed form of words, which are lexically
marked as potential members of compounds. Hunspell improved this, and its recursive
compound checking rules makes it possible to implement the intricate spelling conventions
of Hungarian compounds. For example, using COMPOUNDWORDMAX, COMPOUNDSYLLABLE,
COMPOUNDROOT, SYLLABLENUM options can be set the noteworthy Hungarian `6-3' rule. Further
example in Hungarian, derivate suffixes often modify compounding properties. Hunspell
allows the compounding flags on the affixes, and there are two special flags
(COMPOUNDPERMITFLAG and (COMPOUNDFORBIDFLAG) to permit or prohibit compounding of the
derivations.
Suffixes with this flag forbid compounding of the affixed word.
We also need several Hunspell features for handling German compounding:
# German compounding
# set language to handle special casing of German sharp s
LANG de_DE
# compound flags
COMPOUNDBEGIN U
COMPOUNDMIDDLE V
COMPOUNDEND W
# Prefixes are allowed at the beginning of compounds,
# suffixes are allowed at the end of compounds by default:
# (prefix)?(root)+(affix)?
# Affixes with COMPOUNDPERMITFLAG may be inside of compounds.
COMPOUNDPERMITFLAG P
# for German fogemorphemes (Fuge-element)
# Hint: ONLYINCOMPOUND is not required everywhere, but the
# checking will be a little faster with it.
ONLYINCOMPOUND X
# forbid uppercase characters at compound word bounds
CHECKCOMPOUNDCASE
# for handling Fuge-elements with dashes (Arbeits-)
# dash will be a special word
COMPOUNDMIN 1
WORDCHARS -
# compound settings and fogemorpheme for `Arbeit'
SFX A Y 3
SFX A 0 s/UPX .
SFX A 0 s/VPDX .
SFX A 0 0/WXD .
SFX B Y 2
SFX B 0 0/UPX .
SFX B 0 0/VWXDP .
# a suffix for `Computer'
SFX C Y 1
SFX C 0 n/WD .
# for forbid exceptions (*Arbeitsnehmer)
FORBIDDENWORD Z
# dash prefix for compounds with dash (Arbeits-Computer)
PFX - Y 1
PFX - 0 -/P .
# decapitalizing prefix
# circumfix for positioning in compounds
PFX D Y 29
PFX D A a/PX A
PFX D Ä ä/PX Ä
.
.
PFX D Y y/PX Y
PFX D Z z/PX Z
Example dictionary:
4
Arbeit/A-
Computer/BC-
-/W
Arbeitsnehmer/Z
Accepted compound compound words with the previous resource:
Computer
Computern
Arbeit
Arbeits-
Computerarbeit
Computerarbeits-
Arbeitscomputer
Arbeitscomputern
Computerarbeitscomputer
Computerarbeitscomputern
Arbeitscomputerarbeit
Computerarbeits-Computer
Computerarbeits-Computern
Not accepted compoundings:
computer
arbeit
Arbeits
arbeits
ComputerArbeit
ComputerArbeits
Arbeitcomputer
ArbeitsComputer
Computerarbeitcomputer
ComputerArbeitcomputer
ComputerArbeitscomputer
Arbeitscomputerarbeits
Computerarbeits-computer
Arbeitsnehmer
This solution is still not ideal, however, and will be replaced by a pattern-based
compound-checking algorithm which is closely integrated with input buffer tokenization.
Patterns describing compounds come as a separate input resource that can refer to high-
level properties of constituent parts (e.g. the number of syllables, affix flags, and
containment of hyphens). The patterns are matched against potential segmentations of
compounds to assess wellformedness.
Unicode character encoding
Both Ispell and Myspell use 8-bit ASCII character encoding, which is a major deficiency
when it comes to scalability. Although a language like Hungarian has a standard ASCII
character set (ISO 8859-2), it fails to allow a full implementation of Hungarian
orthographic conventions. For instance, the '--' symbol (n-dash) is missing from this
character set contrary to the fact that it is not only the official symbol to delimit
parenthetic clauses in the language, but it can be in compound words as a special 'big'
hyphen.
MySpell has got some 8-bit encoding tables, but there are languages without standard 8-bit
encoding, too. For example, a lot of African languages have non-latin or extended latin
characters.
Similarly, using the original spelling of certain foreign names like Ångström or Molière
is encouraged by the Hungarian spelling norm, and, since characters 'Å' and 'è' are not
part of ISO 8859-2, when they combine with inflections containing characters only in
ISO 8859-2 (like elative -ből, allative -től or delative -ről with double acute), these
result in words (like Ångströmről or Molière-től.) that can not be encoded using any
single ASCII encoding scheme.
The problems raised in relation to 8-bit ASCII encoding have long been recognized by
proponents of Unicode. It is clear that trading efficiency for encoding-independence has
its advantages when it comes a truly multi-lingual application. There is implemented a
memory and time efficient Unicode handling in Hunspell. In non-UTF-8 character encodings
Hunspell works with the original 8-bit strings. In UTF-8 encoding, affixes and words are
stored in UTF-8, during the analysis are handled in mostly UTF-8, under condition checking
and suggestion are converted to UTF-16. Unicode text analysis and spell checking have a
minimal (0-20%) time overhead and minimal or reasonable memory overhead depends from the
language (its UTF-8 encoding and affixation).
Conversion of aspell dictionaries
Aspell dictionaries can be easily converted into hunspell. Conversion steps:
dictionary (xx.cwl -> xx.wl):
preunzip xx.cwl
wc -l < xx.wl > xx.dic
cat xx.wl >> xx.dic
affix file
If the affix file exists, copy it:
cp xx_affix.dat xx.aff
If not, create it with the suitable character encoding (see xx.dat)
echo "SET ISO8859-x" > xx.aff
or
echo "SET UTF-8" > xx.aff
It's useful to add a TRY option with the characters of the dictionary with frequency order
to set edit distance suggestions:
echo "TRY qwertzuiopasdfghjklyxcvbnmQWERTZUIOPASDFGHJKLYXCVBNM" >>xx.aff
Conversion of aspell dictionaries
Aspell dictionaries can be easily converted into hunspell. Conversion steps:
dictionary (xx.cwl -> xx.wl):
preunzip xx.cwl
wc -l < xx.wl > xx.dic
cat xx.wl >> xx.dic
affix file
If the affix file exists, copy it:
cp xx_affix.dat xx.aff
If not, create it with the suitable character encoding (see xx.dat)
echo "SET ISO8859-x" > xx.aff
or
echo "SET UTF-8" > xx.aff
It's useful to add a TRY option with the characters of the dictionary with frequency order
to set edit distance suggestions:
echo "TRY qwertzuiopasdfghjklyxcvbnmQWERTZUIOPASDFGHJKLYXCVBNM" >>xx.aff
SEE ALSO
hunspell (1), ispell (1), ispell (4)
2017-09-20 hunspell(5)