# StringSearch:SubstringBM

### Import List

        Object
        Object
        RT0
        StringSearch
        StringSearch:SubstringBF

Class List
Factory | This class implements the Boyer-Moore string searching algorithm.
MatchObject |
Matcher |

Class Summary: Factory [Detail]

      +---RT0.Object
           |
           +---Object.Object
                |
                +---StringSearch.Factory
                     |
                     +--StringSearch:SubstringBM.Factory

This class implements the Boyer-Moore string searching algorithm. With a pattern length of M and a string length of N, a search operation never requires more than M+N character comparisons, and about N/M steps if the alphabet is not small and the pattern is not long.

Constructor Summary
InitFactory(Factory)
Method Summary
Compile(String8, Flags): Matcher Compile a expression, for example a regular expression pattern, into a Matcher expression object.
Inherited Methods
From RT0.Object: Finalize From Object.Object: Equals, HashCode, ToString From StringSearch.Factory: Compile, Destroy

Class Summary: MatchObject [Detail]

      +---RT0.Object
           |
           +---Object.Object
                |
                +---StringSearch.MatchObject
                     |
                     +---StringSearch:SubstringBF.MatchObject
                          |
                          +--StringSearch:SubstringBM.MatchObject

Inherited Fields
From StringSearch.MatchObject: endpos, matcher, pos, string
Inherited Methods
From RT0.Object: Finalize From Object.Object: Equals, HashCode, ToString From StringSearch.MatchObject: Destroy From StringSearch:SubstringBF.MatchObject: End, Start

Class Summary: Matcher [Detail]

      +---RT0.Object
           |
           +---Object.Object
                |
                +---StringSearch.Matcher
                     |
                     +---StringSearch:SubstringBF.Matcher
                          |
                          +--StringSearch:SubstringBM.Matcher

Inherited Fields
From StringSearch.Matcher: flags, groups, pattern
Method Summary
Search(String8, LONGINT, LONGINT): MatchObject Like Matcher.SearchChars, but works on an instance of Object.String8.
SearchChars(ARRAY OF CHAR, LONGINT, LONGINT): MatchObject Scans through string looking for a location where this Matcher produces a match, and return a corresponding MatchObject instance.
Inherited Methods
From RT0.Object: Finalize From Object.Object: Equals, HashCode, ToString From StringSearch.Matcher: Destroy From StringSearch:SubstringBF.Matcher: Match, MatchChars, Search, SearchChars

Procedure Summary
SearchStart(Matcher, ARRAY OF CHAR, LONGINT, LONGINT): LONGINT PRIVATE.

Variable Summary
factory-: Factory

Constant Summary
copyString See StringSearch.copyString.
ignoreCase See StringSearch.ignoreCase.

Class Detail: Factory

Constructor Detail

### InitFactory

    PROCEDURE InitFactory(f: Factory)

Method Detail

### Compile

    PROCEDURE (f: Factory) Compile(pattern: String8;
                      flags: Flags): Matcher

> Compile a expression, for example a regular expression pattern, into a Matcher expression object. The matcher object can be used for matching using its Matcher.MatchChars and Matcher.SearchChars methods.

> The pattern's behaviour can be modified by specifying a flags value. The set can include of the following variables: ignoreCase, copyString.

> Result is NIL if the given pattern is invalid.

> Pre-condition: The value of pattern does not contain the character 0X.

> [Description inherited from Compile]

> Redefines: Compile

Class Detail: MatchObject

Class Detail: Matcher

Method Detail

### Search

    PROCEDURE (matcher: Matcher) Search(string: String8;
                     pos: LONGINT;
                     endpos: LONGINT): MatchObject

> Like Matcher.SearchChars, but works on an instance of Object.String8.

> [Description inherited from Search]

> Redefines: Search, Search

### SearchChars

    PROCEDURE (matcher: Matcher) SearchChars(string: ARRAY OF CHAR;
                          pos: LONGINT;
                          endpos: LONGINT): MatchObject

> Scans through string looking for a location where this Matcher produces a match, and return a corresponding MatchObject instance. Returns NIL if no position in the string matches the pattern. Note that this is different from finding a zero-length match at some point in the string.

> The pos and endpos parameters have the same meaning as for the Matcher.MatchChars method.

> [Description inherited from SearchChars]

> Redefines: SearchChars, SearchChars

Procedure Detail

### SearchStart

    PROCEDURE SearchStart(matcher: Matcher;
                          string: ARRAY OF CHAR;
                          pos: LONGINT;
                          endpos: LONGINT): LONGINT

> PRIVATE. Used by module RegexpDFA.

Variable Detail

### factory

    VAR factory-: Factory

Constant Detail

### copyString

    CONST copyString

> See StringSearch.copyString.

### ignoreCase

    CONST ignoreCase

> See StringSearch.ignoreCase.