ProfitPress Mega CDROM2 …eeware (MSDOS)(1992)(Eng)/ProfitPress-MegaCDROM2.B6I/TEXT/UTILITY/SSPELL11.ZIP/README

Text File | 1992-01-26 | 7.7 KB | 189 lines

             sspell - similar to Unix spell
                        version 1.1

 Author: Maurice Castro
 Release Date: 26 Jan 1992
 Bug Reports: [e-mail]

 This code has been placed by the Author into the Public Domain.
 The code is NOT covered by any warranty, the user of the code is
 solely responsible for determining the fitness of the program
 for their purpose. No liability is accepted by the author for
 the direct or indirect losses incurred through the use of this
 program.

 Segments of this code may be used for any purpose that the user
 deems appropriate. It would be polite to acknowledge the source
 of the code. If you modify the code and redistribute it please
 include a message indicating your changes and how users may
 contact you for support.

 The author reserves the right to issue the official version of
 this program. If you have useful suggestions or changes for the
 code, please forward them to the author so that they might be
 incorporated into the official version

 Please forward bug reports to the author via Internet.

* Introduction

The program SSPELL was written by the author to provide a Unix like
spell checker on a PC. There are several utilities of this type already
available, however, most lacked at least one of the following:

    1. Public Domain
    2. Source Code
    3. Simple, editable word list structure
    4. Configurable prefix and suffix list.
    5. To use minimal memory
    6. To have an unlimited word list length
    7. Reasonable speed
    8. Portable

The SSPELL program provides all these features. The program currently
compiles under Turbo C++ (Borland) for MS-DOS and cc for Unix (OSx for
Pyramid, SunOS for Sun 3/50, Ultrix for Decstation 2100). Minor
modification will be required to compile under other Unix variants.

* Features

The SSPELL program uses a sorted plain ASCII word list for its dictionary.
This makes adding new words to the list easy. Simply add the words and
re-sort the list.

To gain speed, without loading the complete list into memory, a cache
of words recently recovered from the word list is maintained, the disk
is only searched if the word is not found in the cache.

A suffix/prefix list is used to allow a smaller dictionary to be used.

* Operation

Edit the config.h file to set up the required default locations and
compile the code. Place the dictionary in the file specified in the
config.h and make sure that the index file is writable. SSPELL should
now be ready for use.

Performance gains may be had by altering the parameters found in the
config.h file. Increasing CACHESIZE increases the memory usage of the
program, but decreases disk search time. IDXSIZ and HASHWID control
the size of the index to the disk file. HASHWID determines the maximum
number of characters compared to determine if an item occurs in a given
slot. IDXSIZ determines the number of slots.

A typical IBM-PC implementation could be written as:

    #define DICTIONARY "c:\\utility\\dict\\main.dct"
    #define INDEX "c:\\utility\\dict\\main.idx"
    #define RULE "c:\\utility\\dict\\rule.lst"
    #define CACHESIZE 1000
    #define ROOTNAME "c:\\tmp\\sspell"
    #define SORT "c:\\dos\\sort"

    #define MAXSTR 128
    #define SEPSTR " \n\r\t!@#$%^&*(),.<>~`\":;|/\\{}[]"

    /* HASHWID must always be 2 or greater */
    #define HASHWID 8
    #define IDXSIZ 1000

* Command Line

SSPELL has the following command line options:

    sspell [-v] [-x] [-D dict] [-I index] [-R rule]
           [-C cachesize] [file] ...

-v    all words not actually in the word list are printed and plausible
    derivations from the word list are indicated

-x     all plausible stems are output

-D    `dict' is the pathname of an alternate dictionary

-I    `index' is the pathname of an alternate index. This should be
    used if using a personalised dictionary or if the index file is
    unwriteable.

-R    `rule' is the pathname of an alternate rule list

-C    `cachesize' is the size of the cache of words found in the
    dictionary.

SSPELL will take input from a list of files on the command line or from
stdin if no files are supplied.

The dictionary must be in sorted order with the capital letters folded onto
the small letters. (Using Unix sort: sort -fu). The case of words in the
dictionary is significant. Any letter appearing as a capital in the
dictionary must appear as a capital in the text to be regarded as spelled
correctly.

The format of the rule list is fixed. `#' in the first column indicates a
comment. All other lines are of the form:

      pre|post <prefix/suffix> <required> <forbiden> <delete>

Any field not used must be filled with a `-'. The following examples
illustrate the features of the rules.

    pre un - - -
    post ive - e -
    post ive e - e
    post ied y ay,ey,iy,oy,uy y

The prefix rules are simple, their are no required or forbidden sequences
and nothing to delete. Prefixes must not be more complex.

The suffix rules are more complex. These rule specify the ending to be
added to the root after the deletion of the delete field, provided that
the word has a required ending, provided that the combination is not
forbidden. For example: carried.

    root:         carry
    required `y': carry           the last letter is a `y'
    forbidden:                    the word does not end in a
                                  forbidden sequence
    delete `y':   carr
    suffix `ied': carried

* Overview of Internal Operation

SSPELL creates an index file which speeds access to the main dictionary,
the index is a simple list of the first part of words evenly spaced through
the dictionary, the number of significant letters and the number of slots
are set using hash defines in the config.h file.

The index file is only created if: No index file exists or the dictionary
has been modified since the index was created. The Dictionary is checked
for correct ordering during the creation of the index file.

Words are checked for correct spelling by initially checking the cache. The
cache is a move to front list, so more recently used words are at the
front of the cache. The cache size is bounded by a limit set in the config.h
file. If the word is not found in the cache then an exact match is checked
for in the file. If no exact match is found then a derivation is checked
for in the cache and subsequently in the file. If a word in the dictionary
matches either a derivation or the original then the dictionary word is
inserted at the head of the cache list.

Hyphenation and number identification have been left out of the above
description. The output of the search process is put in a file, the
file is then sorted using the local operating system sorting utility.
The result is then listed on standard out such that duplicated lines
appear only once.

* Acknowledgments

My thanks to people who have contributed to this program:

Michael Oldfield ([e-mail]) for a number of bug fixes

* Conclusion

I hope that this program proves useful. Comments and suggestions welcomed;
I can be contavcted via E-Mail at [e-mail]

        Maurice Castro