SUMMARY: MODULE | CLASS | TYPE | PROC | VAR | CONST | DETAIL: TYPE | PROC | VAR | CONST |
This module specifies a common framework for string search algorithms. Examples for implementations are StringSearch:SubstringBF, which does brute-force searching for substrings, and StringSearch:Regexp, a regular expression engine.
Object Object RT0
Class List | |
Factory | Factory for Matcher objects. |
MatchObject | Represents the result of a successful match or search operation. |
Matcher | A representation of a search pattern. |
Class Summary: Factory [Detail] | |
+---RT0.Object | +---Object.Object | +--StringSearch.Factory Factory for Matcher objects. An instance of Matcher is created from a textual description of a search pattern by calling Factory.Compile. | |
Constructor Summary | |
InitFactory(Factory) | |
Method Summary | |
Compile(String8, Flags): Matcher Compile a expression, for example a regular expression pattern, into a Matcher expression object. | |
Destroy() | |
Inherited Methods | |
From RT0.Object: From Object.Object: |
Class Summary: MatchObject [Detail] | |
+---RT0.Object | +---Object.Object | +--StringSearch.MatchObject Represents the result of a successful match or search operation. | |
Field Summary | |
endpos-: LONGINT The value of endpos which was passed to a search or match function. | |
matcher-: Matcher The matcher object whose match or search method produced this MatchObject instance. | |
pos-: LONGINT The value of pos which was passed to a search or match function. | |
string-: String8 The string passed to a match or search function. | |
Constructor Summary | |
InitMatchObject(MatchObject, LONGINT, LONGINT, Matcher, String8) | |
Method Summary | |
Destroy() | |
End(LONGINT): LONGINT Returns the index of the end of the substring matched by group. | |
Start(LONGINT): LONGINT Returns the index of the start of the substring matched by group. | |
Inherited Methods | |
From RT0.Object: From Object.Object: |
Class Summary: Matcher [Detail] | |
+---RT0.Object | +---Object.Object | +--StringSearch.Matcher A representation of a search pattern. An instance of Matcher is applied to a string by calling one of the match or search methods. | |
Field Summary | |
flags-: Flags The flags argument used when the matcher object was compiled. | |
groups-: LONGINT The number of groups defined in the pattern string. | |
pattern-: String8 The pattern string from which the matcher object was compiled. | |
Constructor Summary | |
InitMatcher(Matcher, String8, Flags, LONGINT) | |
Method Summary | |
Destroy() | |
Match(String8, LONGINT, LONGINT): MatchObject Like Matcher.MatchChars, but works on an instance of Object.String8. | |
MatchChars(ARRAY OF CHAR, LONGINT, LONGINT): MatchObject Returns a corresponding MatchObject instance, if zero or more characters at the beginning of string match this Matcher. | |
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: From Object.Object: |
Type Summary | |
Flags = SET |
Constant Summary | |
copyString If set, then the match and search functions working an character arrays create a new copy of the searched string for MatchObject.string. | |
ignoreCase Perform case-insensitive matching. |
Class Detail: Factory |
Constructor Detail |
PROCEDURE InitFactory(f: Factory)
Method Detail |
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.
PROCEDURE (f: Factory) Destroy()
Class Detail: MatchObject |
Field Detail |
FIELD endpos-: LONGINT
The value of endpos which was passed to a search or match function. This is the index into the string beyond which the matcher engine will not go.
FIELD matcher-: Matcher
The matcher object whose match or search method produced this MatchObject instance.
FIELD pos-: LONGINT
The value of pos which was passed to a search or match function. This is the index into the string at which the matcher engine started looking for a match.
FIELD string-: String8
The string passed to a match or search function. This field is NIL if Matcher.MatchChars or Matcher.SearchChars is called without the flag copyString.
Constructor Detail |
PROCEDURE InitMatchObject(m: MatchObject; pos: LONGINT; endpos: LONGINT; matcher: Matcher; string: String8)
Method Detail |
PROCEDURE (m: MatchObject) Destroy()
PROCEDURE (m: MatchObject) End(group: LONGINT): LONGINT
Returns the index of the end of the substring matched by group. See MatchObject.Start.
PROCEDURE (m: MatchObject) Start(group: LONGINT): LONGINT
Returns the index of the start of the substring matched by group. A group of `0' refers to the whole matched substring. Returns `-1' if the group exists but did not contribute to the match. For a match object m, and a group g that did contribute to the match, the substring matched by group g is `string[m.Start(g), m.End(g)['. Note that `m.Start(g)' will equal `m.End(g)' if g matched a null string.
Note: Not all matcher implementations implement groups other than the whole match.
Pre-condition: `0 <= group <= m.matcher.groups'
Class Detail: Matcher |
Field Detail |
FIELD flags-: Flags
The flags argument used when the matcher object was compiled.
FIELD groups-: LONGINT
The number of groups defined in the pattern string. If there are no groups, for example because the matcher does not support them, the field is zero.
FIELD pattern-: String8
The pattern string from which the matcher object was compiled.
Constructor Detail |
PROCEDURE InitMatcher(matcher: Matcher; pattern: String8; flags: Flags; groups: LONGINT)
Method Detail |
PROCEDURE (matcher: Matcher) Destroy()
PROCEDURE (matcher: Matcher) Match(string: String8; pos: LONGINT; endpos: LONGINT): MatchObject
Like Matcher.MatchChars, but works on an instance of Object.String8.
PROCEDURE (matcher: Matcher) MatchChars(string: ARRAY OF CHAR; pos: LONGINT; endpos: LONGINT): MatchObject
Returns a corresponding MatchObject instance, if zero or more characters at the beginning of string match this Matcher. Returns NIL if the string does not match the pattern. Note that this is different from a zero-length match.
Note: If you want to locate a match anywhere in string, use Matcher.Search instead.
The second parameter pos gives an index in the string where the search is to start, for example 0 to start at the beginning of the string.
The parameter endpos limits how far the string will be searched. It will be as if the string is endpos characters long, so only the characters in `[pos, endpos[' will be searched for a match. A value of `-1' is equivalent to an endpos of `Length(string)'.
Pre-condition: The start position is within the string `0 <= pos <= Length(string)', and the given end position is either `-1', or between the start position and the end of the string `pos <= endpos <= Length(string)'.
PROCEDURE (matcher: Matcher) Search(string: String8; pos: LONGINT; endpos: LONGINT): MatchObject
Like Matcher.SearchChars, but works on an instance of Object.String8.
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.
Type Detail |
TYPE Flags = SET
Constant Detail |
CONST copyString
If set, then the match and search functions working an character arrays create a new copy of the searched string for MatchObject.string. Setting this flag is only useful if you intend to extract matched substrings from an instance of MatchObject. Note that most matchers do not support capturing matched substrings.
CONST ignoreCase
Perform case-insensitive matching. For example, a regular expression like `[A-Z]' will match lowercase letters, too.