Note:
A simple "spellchecking" program is included in this distribution.
It is a perl program named "spellcheck". It simply prints the
analysis of the input text; it provides no way to modify the text.
It is simply given as a demonstration of the module. Type
spellcheck -h
for a usage summary. If no input files are specified, it will
read from stdin. After each line of input, it will print the
analysis of the terms. By default, it only gives output for
terms which are "incorrect". Give it the -v option to have it
report on the "correct" terms as well.
Tests:
'make test' currently does nothing. To test the installation,
try out the "spellcheck" program provided.
__POD__
NAME
Lingua::Ispell.pm - a module encapsulating access to the
Ispell program.
Note: this module was previously known as Text::Ispell; if
you have Text::Ispell installed on your system, it is now
obsolete and should be replaced by Lingua::Ispell.
NOTA BENE
ispell, when reporting on misspelled words, indicates the
string it was unable to verify, as well as its starting
offset in the input line. No such information is returned
for words which are deemed to be correctly spelled. For
example, in a line like "Can't buy a thrill", ispell simply
reports that the line contained four correctly spelled
words.
Lingua::Ispell would like to identify which substrings of
the input line are words -- correctly spelled or otherwise.
It used to attempt to split the input line into words
according to the same rules ispell uses; but that has proven
to be very difficult, resulting in both slow and error-prone
code.
Consequences
Lingua::Ispell now operates only in "terse" mode. In this
mode, only misspelled words are reported. Words which
ispell verifies as correctly spelled are silently accepted.
In the report structures returned by spellcheck(), the
'term' member is now always identical to the 'original'
member; of the two, you should probably use the 'term'
member. (Also consider the 'offset' member.) ispell does
not report this information for correctly spelled words; if
at some point in the future this capability is added to
ispell, Lingua::Ispell will be updated to take advantage of
it.
Use of the $word_chars variable has been removed; setting it
no longer has any effect.
terse_mode() now does nothing.
SYNOPSIS
# Brief:
use Lingua::Ispell;
Lingua::Ispell::spellcheck( $string );
# or
use Lingua::Ispell qw( spellcheck ); # import the function
spellcheck( $string );
# Useful:
use Lingua::Ispell qw( :all ); # import all symbols
for my $r ( spellcheck( "hello hacking perl shrdlu 42" ) ) {
print "$r->{'type'}: $r->{'term'}\n";
}
DESCRIPTION
Lingua::Ispell::spellcheck() takes one argument. It must be
a string, and it should contain only printable characters.
One allowable exception is a terminal newline, which will be
chomped off anyway. The line is fed to a coprocess running
ispell for analysis. ispell parses the line into "terms"
according to the language-specific rules in effect.
The result of ispell's analysis of each term is a
categorization of the term into one of six types: ok,
compound, root, miss, none, and guess. Some of these carry
additional information. The first three types are
"correctly" spelled terms, and the last three are for
"incorrectly" spelled terms.
Lingua::Ispell::spellcheck returns a list of objects, each
corresponding to a term in the spellchecked string. Each
object is a hash (hash-ref) with at least two entries:
'term' and 'type'. The former contains the term ispell is
reporting on, and the latter is ispell's determination of
that term's type (see above). For types 'ok' and 'none',
that is all the information there is. For the type 'root',
an additional hash entry is present: 'root'. Its value is
the word which ispell identified in the dictionary as being
the likely root of the current term. For the type 'miss',
an additional hash entry is present: 'misses'. Its value is
an ref to an array of words which ispell identified as being
"near-misses" of the current term, when scanning the
dictionary.
NOTE
As mentioned above, Lingua::Ispell::spellcheck() currently
only reports on misspelled terms.
EXAMPLE
use Lingua::Ispell qw( spellcheck );
Lingua::Ispell::allow_compounds(1);
for my $r ( spellcheck( "hello hacking perl salmoning fruithammer shrdlu 42" ) ) {
if ( $r->{'type'} eq 'ok' ) {
# as in the case of 'hello'
print "'$r->{'term'}' was found in the dictionary.\n";
}
elsif ( $r->{'type'} eq 'root' ) {
# as in the case of 'hacking'
print "'$r->{'term'}' can be formed from root '$r->{'root'}'\n";
}
elsif ( $r->{'type'} eq 'miss' ) {
# as in the case of 'perl'
print "'$r->{'term'}' was not found in the dictionary;\n";
print "Near misses: @{$r->{'misses'}}\n";
}
elsif ( $r->{'type'} eq 'guess' ) {
# as in the case of 'salmoning'
print "'$r->{'term'}' was not found in the dictionary;\n";
print "Root/affix Guesses: @{$r->{'guesses'}}\n";
}
elsif ( $r->{'type'} eq 'compound' ) {
# as in the case of 'fruithammer'
print "'$r->{'term'}' is a valid compound word.\n";
}
elsif ( $r->{'type'} eq 'none' ) {
# as in the case of 'shrdlu'
print "No match for term '$r->{'term'}'\n";
}
# and numbers are skipped entirely, as in the case of 42.
}
ERRORS
Lingua::Ispell::spellcheck() starts the ispell coprocess if
the coprocess seems not to exist. Ordinarily this is simply
the first time it's called.
ispell is spawned via the Open2::open2() function, which
throws an exception (i.e. dies) if the spawn fails. The
caller should be prepared to catch this exception -- unless,
of course, the default behavior of die is acceptable.
Nota Bene
The full location of the ispell executable is stored in the
variable $Lingua::Ispell::path. The default value is
/usr/local/bin/ispell. If your ispell executable has some
name other than this, then you must set
$Lingua::Ispell::path accordingly before you call
Lingua::Ispell::spellcheck() (or any other function in the
module) for the first time!
AUX FUNCTIONS
add_word(word)
Adds a word to the personal dictionary. Be careful of
capitalization. If you want the word to be added "case-
insensitively", you should call add_word_lc()
add_word_lc(word)
Adds a word to the personal dictionary, in lower-case form.
This allows ispell to match it in a case-insensitive manner.
accept_word(word)
Similar to adding a word to the dictionary, in that it
causes ispell to accept the word as valid, but it does not
actually add it to the dictionary. Presumably the effects
of this only last for the current ispell session, which will
mysteriously end if any of the coprocess-restarting
functions are called...
parse_according_to(formatter)
Causes ispell to parse subsequent input lines according to
the specified formatter. As of ispell v. 3.1.20, only 'tex'
and 'nroff' are supported.
set_params_by_language(language)
Causes ispell to set its internal operational parameters
according to the given language. Legal arguments to this
function, and its effects, are currently unknown by the
author of Lingua::Ispell.
save_dictionary()
Causes ispell to save the current state of the dictionary to
its disk file. Presumably ispell would ordinarily only do
this upon exit.
terse_mode(bool:terse)
NOTE: This function has been disabled! Lingua::Ispell now
always operates in terse mode.
In terse mode, ispell will not produce reports for "correct"
words. This means that the calling program will not receive
results of the types 'ok', 'root', and 'compound'.
FUNCTIONS THAT RESTART ISPELL
The following functions cause the current ispell coprocess,
if any, to terminate. This means that all the changes to the
state of ispell made by the above functions will be lost,
and their respective values reset to their defaults. The
only function above whose effect is persistent is
save_dictionary().
Perhaps in the future we will figure out a good way to make
this state information carry over from one instantiation of
the coprocess to the next.
allow_compounds(bool)
When this value is set to True, compound words are accepted
as legal -- as long as both words are found in the
dictionary; more than two words are always illegal. When
this value is set to False, run-together words are
considered spelling errors.
The default value of this setting is dictionary-dependent,
so the caller should set it explicitly if it really matters.
make_wild_guesses(bool)
This setting controls when ispell makes "wild" guesses.
If False, ispell only makes "sane" guesses, i.e. possible
root/affix combinations that match the current dictionary;
only if it can find none will it make "wild" guesses, which
don't match the dictionary, and might in fact be illegal
words.
If True, wild guesses are always made, along with any "sane"
guesses. This feature can be useful if the dictionary has a
limited word list, or a word list with few suffixes.
The default value of this setting is dictionary-dependent,
so the caller should set it explicitly if it really matters.
use_dictionary([dictionary])
Specifies what dictionary to use instead of the default.
Dictionary names are actually file names, and are searched
for according to the following rule: if the name does not
contain a slash, it is looked for in the directory
containing the default dictionary, typically /usr/local/lib.
Otherwise, it is used as is: if it does not begin with a
slash, it is construed from the current directory.
If no argument is given, the default dictionary will be
used.
use_personal_dictionary([dictionary])
Specifies what personal dictionary to use instead of the
default.
Dictionary names are actually file names, and are searched
for according to the following rule: if the name begins
with a slash, it is used as is (i.e. it is an absolute path
name). Otherwise, it is construed as relative to the user's
home directory ($HOME).
If no argument is given, the default personal dictionary
will be used.
FUTURE ENHANCEMENTS
ispell options:
-w chars
Specify additional characters that can be part of a word.
DEPENDENCIES
Lingua::Ispell uses the external program ispell, which is
the "International Ispell", available at
http://fmg-www.cs.ucla.edu/geoff/ispell.html
as well as various archives and mirrors, such as
ftp://ftp.math.orst.edu/pub/ispell-3.1/
This is a very popular program, and may already be installed
on your system.
Lingua::Ispell also uses the standard perl modules
FileHandle, IPC::Open2, and Carp.
AUTHOR
jdporter@min.net (John Porter)
COPYRIGHT
This module is free software; you may redistribute it and/or
modify it under the same terms as Perl itself.
