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Visual Eiffel port of Halstenbach iss-match v1.0

Written by dougpardee@my-dejanews.com.

• Targets Visual Eiffel.
• Version 1.0 — 5 June 1999.
• Eiffel Forum Freeware License.

issmatve.zip (124,864 bytes) — source code

OVERVIEW:

Text searching:

SUBSTRING class searches for a fixed string, going either forward or backward. It is suitable for searching through large quantities of text. Searches can be case-sensitive or insensitive.

Pattern matching:

REGEXP class matches a text string against a regular expression. Matching can be case-sensitive or insensitive. The regular expression can be constrained to matching the entire string, to matching the beginning or the end of the string, or can be allowed to search for a matching sequence, either forward from the start or backward from the end of the text string. Matching can treat new-line characters as end-of-line or as ordinary characters.

WILDCARD class is similar to REGEXP except that it uses a simplified pattern syntax similar to file-name wildcards.

MISSPELLED class is similar to REGEXP except that it searches for a fixed text string, not a pattern. It allows a specified amount of variation (misspelling) between the search string and the target.

All three of these pattern matchers provide two interfaces. The full "match_*" features allow you to query the character positions of the matched string and (for REGEXP) of any substrings. The "matches_*" features are queries which provide only a True/False match indication.

REGEXP_EXTRACTOR and WILDCARD_EXTRACTOR are variants which provide an easy way for you to do the matching and then retrieve the matching substring(s). The extractors require a small amount of care in order to prevent wasting memory. See the HTML page for more information. It's not clear why no MISSPELLED_EXTRACTOR is provided, but it should be simple enough to create.

Text splitting:

SPLITTER class breaks a text string into an arrya of substrings, using any of the text search or pattern match objects to define the separators.

INSTALLATION NOTES:

The supplied eif_match.lib was compiled with Microsoft Visual C++. In addition to this lib, you will also need to link in Microsoft's "libc.lib" to provide basic string functions (strcpy, to_upper, etc.). If you don't have access to Microsoft's libc.lib, you'll need to recompile the three C routines contained in the Clib directory with whatever C compiler you have (remember that Visual Eiffel's linker requires that the object files be in COFF format). You may need to add #defines into eif_match.h to define register1 through register6 as being nothing or "register".

Specify the eif_match.lib and libc.lib files in the "Object Files" section of the Project/Options dialog.

There is an example program in the directory Examples, class TEST. This should be built as a console EXE.

DETAILS OF THE VISUAL EIFFEL PORT:

There are many changes which will affect classes which inherit from these. Some of these changes were unavoidable, as Visual Eiffel's implementations of ARRAY and STRING are internally a bit different than the Halstenbach and ISE implementations. The following changes made were:

• The REGEXP, SUBSTRING, and MISSPELLED classes needed considerable rework because of the way that they were handling memory which was shared between C and Eiffel. Two new classes, MEMORY_BLOCK and ARRAY_MEMORY_BLOCK[G], were added in order to provide a unified approach to the memory handling.

• REGEXP.match_against and REGEXP.matches_against also needed their respective local variables "flags" changed from "like flag" (which is of type INTEGER_REF) to type "INTEGER". This corrected a problem where the variable was not being passed to the C code. (Presumably, the address was being passed rather than the integer value).

• The WILDCARD class needed a bit of modification in its STRING handling. Visual Eiffel has a documented incompatibility in that STRING.make(n) sets the string's "count" to the length specified rather than to 0 as required by ELKS-95. The original WILDCARD code also used the obsolete feature names "append" and "extend". These have been changed to "append_string" and "append_character" respectively, which are the names specified by ELKS-95.

• The SPLITTER class needed a minor modification because Visual Eiffel's ARRAY class retains the "count" and computes "upper", rather than vice-versa.

• The TEST class was modified to use standard 'print' instead of "print_line". A couple of typos were also corrected.

CREDITS:

This Visual Eiffel port by Doug Pardee , released under the Eiffel Forum Freeware License.

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