| java.lang.Object
 org.apache.oro.text.regex.StringSubstitution
org.apache.oro.text.regex.Perl5Substitution
| Perl5Substitution | | public class Perl5Substitution extends StringSubstitution (Code) | | Perl5Substitution implements a Substitution consisting of a
literal string, but allowing Perl5 variable interpolation referencing
saved groups in a match. This class is intended for use with
Util.substitute Util.substitute .
The substitution string may contain variable interpolations referring
to the saved parenthesized groups of the search pattern.
A variable interpolation is denoted by $1, or $2,
or $3, etc. If you want such expressions to be
interpreted literally, you should set the numInterpolations
parameter to INTERPOLATE_NONE . It is easiest to explain
what an interpolated variable does by giving an example:
Suppose you have the pattern b\d+: and you want to substitute
the b's for a's and the colon for a dash in parts of
your input matching the pattern. You can do this by changing the
pattern to b(\d+): and using the substitution expression
a$1-. When a substitution is made, the $1 means
"Substitute whatever was matched by the first saved group of the
matching pattern." An input of b123: after substitution
would yield a result of a123-. But there's a little more
to be aware of. If you set the numInterpolations parameter to
INTERPOLATE_ALL, then every time a match is found, the
interpolation variables are computed relative to that match.
But if numInterpolations is set to some positive integer, then
only the interpolation variables for the first numInterpolations
matches are computed relative to the most recent match. After that,
the remaining substitutions have their variable interpolations performed
relative to the numInterpolations 'th match. So using the
previously mentioned pattern and substitution expression, if you have
an input of Tank b123: 85 Tank b256: 32 Tank b78: 22
and use a numInterpolations value of INTERPOLATE_ALL and
numSubs value (see
Util.substitute Util.substitute )
of SUBSTITUTE_ALL, then your result will be:
Tank a123- 85 Tank a256- 32 Tank a78- 22
But if you set numInterpolations to 2 and keep
numSubs with a value of SUBSTITUTE_ALL, your result is:
Tank a123- 85 Tank a256- 32 Tank a256- 22
Notice how the last substitution uses the same value for $1
as the second substitution.
A final thing to keep in mind is that if you use an interpolation variable
that corresponds to a group not contained in the match, then it is
interpreted as the empty string. So given the regular expression from the
example, and a substitution expression of a$2-, the result
of the last sample input would be:
Tank a- 85 Tank a- 32 Tank a- 22
The special substitution $& will interpolate the entire portion
of the input matched by the regular expression. $0 will
do the same, but it is recommended that it be avoided because the
latest versions of Perl use $0 to store the program name rather
than duplicate the behavior of $&.
Also, the result of substituting $ followed by a non-positive integer
is undefined. In order to include a $ in a substitution, it should
be escaped with a backslash (e.g., "\\$0").
Perl5 double-quoted string case modification is also supported in
the substitution. The following escape sequences are supported:
- \\U
- make substitution uppercase until end of substitution or \\E
- \\u
- make next character uppercase
- \\L
- make substitution uppercase until end of substitution or \\E
- \\l
- make next character uppercase
- \\E
- mark the end of the case modification
The double backslashes are shown to remind you that to make a
backslash get past Java's string handling and appear as a backslash
to the substitution, you must escape the backslash.
version:
@version@
since:
1.1
See Also: Substitution
See Also: Util
See Also: Util.substitute
See Also: Substitution
See Also: StringSubstitution |
| Constructor Summary | |
| public | Perl5Substitution()
Default constructor initializing substitution to a zero length
String and the number of interpolations to
Perl5Substitution.INTERPOLATE_ALL . | | public | Perl5Substitution(String substitution)
Creates a Perl5Substitution using the specified substitution
and setting the number of interpolations to
Perl5Substitution.INTERPOLATE_ALL . | | public | Perl5Substitution(String substitution, int numInterpolations)
Creates a Perl5Substitution using the specified substitution
and setting the number of interpolations to the specified value.
Parameters:
substitution - The string to use as a substitution.
Parameters:
numInterpolations - If set to INTERPOLATE_NONE, interpolation variables areinterpreted literally and not as references to the savedparenthesized groups of a pattern match. |
| Method Summary | |
| void | _calcSub(StringBuffer buffer, MatchResult result)
| | String | _finalInterpolatedSub(MatchResult result)
| | public void | appendSubstitution(StringBuffer appendBuffer, MatchResult match, int substitutionCount, PatternMatcherInput originalInput, PatternMatcher matcher, Pattern pattern)
Appends the substitution to a buffer containing the original input
with substitutions applied for the pattern matches found so far.
See
Substitution.appendSubstitution Substitution.appendSubstition() for more details regarding the expected behavior of this method.
Parameters:
appendBuffer - The buffer containing the new string resultingfrom performing substitutions on the original input.
Parameters:
match - The current match causing a substitution to be made. | | public void | setSubstitution(String substitution)
Sets the substitution represented by this Perl5Substitution, also
setting the number of interpolations to
Perl5Substitution.INTERPOLATE_ALL .
You should use this method in order to avoid repeatedly allocating new
Perl5Substitutions. | | public void | setSubstitution(String substitution, int numInterpolations)
Sets the substitution represented by this Perl5Substitution, also
setting the number of interpolations to the specified value.
You should use this method in order to avoid repeatedly allocating new
Perl5Substitutions. |
| INTERPOLATE_ALL | | final public static int INTERPOLATE_ALL(Code) | | A constant used when creating a Perl5Substitution indicating that
interpolation variables should be computed relative to the most
recent pattern match.
|
| INTERPOLATE_NONE | | final public static int INTERPOLATE_NONE(Code) | | A constant used when creating a Perl5Substitution indicating that
interpolation variables should be interpreted literally, effectively
disabling interpolation.
|
| _OPCODE_COPY | | final static int _OPCODE_COPY(Code) | | A constant declaring opcode for copy operation.
|
| _OPCODE_ENDCASE_MODE | | final static int _OPCODE_ENDCASE_MODE(Code) | | A constant declaring opcode for lowercase mode operation.
|
| _OPCODE_LOWERCASE_CHAR | | final static int _OPCODE_LOWERCASE_CHAR(Code) | | A constant declaring opcode for lowercase char operation.
|
| _OPCODE_LOWERCASE_MODE | | final static int _OPCODE_LOWERCASE_MODE(Code) | | A constant declaring opcode for lowercase mode operation.
|
| _OPCODE_UPPERCASE_CHAR | | final static int _OPCODE_UPPERCASE_CHAR(Code) | | A constant declaring opcode for uppercase char operation.
|
| _OPCODE_UPPERCASE_MODE | | final static int _OPCODE_UPPERCASE_MODE(Code) | | A constant declaring opcode for lowercase mode operation.
|
| _numInterpolations | | int _numInterpolations(Code) | | |
| _subOpcodes | | int[] _subOpcodes(Code) | | |
| _subOpcodesCount | | int _subOpcodesCount(Code) | | |
| _substitutionChars | | char[] _substitutionChars(Code) | | |
| Perl5Substitution | | public Perl5Substitution(String substitution)(Code) | | Creates a Perl5Substitution using the specified substitution
and setting the number of interpolations to
Perl5Substitution.INTERPOLATE_ALL .
Parameters:
substitution - The string to use as a substitution. |
| Perl5Substitution | | public Perl5Substitution(String substitution, int numInterpolations)(Code) | | Creates a Perl5Substitution using the specified substitution
and setting the number of interpolations to the specified value.
Parameters:
substitution - The string to use as a substitution.
Parameters:
numInterpolations - If set to INTERPOLATE_NONE, interpolation variables areinterpreted literally and not as references to the savedparenthesized groups of a pattern match. If set to INTERPOLATE_ALL , all variable interpolationsare computed relative to the pattern match responsible forthe current substitution. If set to a positive integer,the first numInterpolations substitutions havetheir variable interpolation performed relative to themost recent match, but the remaining substitutions havetheir variable interpolations performed relative to the numInterpolations 'th match. |
| appendSubstitution | | public void appendSubstitution(StringBuffer appendBuffer, MatchResult match, int substitutionCount, PatternMatcherInput originalInput, PatternMatcher matcher, Pattern pattern)(Code) | | Appends the substitution to a buffer containing the original input
with substitutions applied for the pattern matches found so far.
See
Substitution.appendSubstitution Substitution.appendSubstition() for more details regarding the expected behavior of this method.
Parameters:
appendBuffer - The buffer containing the new string resultingfrom performing substitutions on the original input.
Parameters:
match - The current match causing a substitution to be made.
Parameters:
substitutionCount - The number of substitutions that have beenperformed so far by Util.substitute.
Parameters:
originalInput - The original input upon which the substitutions arebeing performed. This is a read-only parameter and is not modified.
Parameters:
matcher - The PatternMatcher used to find the current match.
Parameters:
pattern - The Pattern used to find the current match. |
| setSubstitution | | public void setSubstitution(String substitution)(Code) | | Sets the substitution represented by this Perl5Substitution, also
setting the number of interpolations to
Perl5Substitution.INTERPOLATE_ALL .
You should use this method in order to avoid repeatedly allocating new
Perl5Substitutions. It is recommended that you allocate a single
Perl5Substitution and reuse it by using this method when appropriate.
Parameters:
substitution - The string to use as a substitution. |
| setSubstitution | | public void setSubstitution(String substitution, int numInterpolations)(Code) | | Sets the substitution represented by this Perl5Substitution, also
setting the number of interpolations to the specified value.
You should use this method in order to avoid repeatedly allocating new
Perl5Substitutions. It is recommended that you allocate a single
Perl5Substitution and reuse it by using this method when appropriate.
Parameters:
substitution - The string to use as a substitution.
Parameters:
numInterpolations - If set to INTERPOLATE_NONE, interpolation variables areinterpreted literally and not as references to the savedparenthesized groups of a pattern match. If set to INTERPOLATE_ALL , all variable interpolationsare computed relative to the pattern match responsible forthe current substitution. If set to a positive integer,the first numInterpolations substitutions havetheir variable interpolation performed relative to themost recent match, but the remaining substitutions havetheir variable interpolations performed relative to the numInterpolations 'th match. |
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