Examples of org.jregex.Pattern

org.jregex.Pattern

A handle for a precompiled regular expression.
To match a regular expression myExpr against a text myString one should first create a Pattern object:

 Pattern p=new Pattern(myExpr);

then obtain a Matcher object:

 Matcher matcher=p.matcher(myText);

The latter is an automaton that actually performs a search. It provides the following methods:

search for matching substrings : matcher.find() or matcher.findAll();

test whether the text matches the whole pattern : matcher.matches();

test whether the text matches the beginning of the pattern : matcher.matchesPrefix();

search with custom options : matcher.find(int options)

Flags
Flags (see REFlags interface) change the meaning of some regular expression elements at compiletime. These flags may be passed both as string(see Pattern(String,String)) and as bitwise OR of:

REFlags.IGNORE_CASE - enables case insensitivity

REFlags.MULTILINE - forces "^" and "$" to match both at the start and the end of line;

REFlags.DOTALL - forces "." to match eols('\r' and '\n' in ASCII);

REFlags.IGNORE_SPACES - literal spaces in expression are ignored for better readability;

REFlags.UNICODE - the predefined classes('\w','\d',etc) are referenced to Unicode;

REFlags.XML_SCHEMA - permits XML Schema regular expressions syntax extentions.

Multithreading
Pattern instances are thread-safe, i.e. the same Pattern object may be used by any number of threads simultaniously. On the other hand, the Matcher objects are NOT thread safe, so, given a Pattern instance, each thread must obtain and use its own Matcher. @see REFlags @see Matcher @see Matcher#setTarget(java.lang.String) @see Matcher#setTarget(java.lang.String,int,int) @see Matcher#setTarget(char[],int,int) @see Matcher#setTarget(java.io.Reader,int) @see MatchResult @see MatchResult#group(int) @see MatchResult#start(int) @see MatchResult#end(int) @see MatchResult#length(int) @see MatchResult#charAt(int,int) @see MatchResult#prefix() @see MatchResult#suffix()

                @Override
                public Object activate(IokeObject self, Object on, List<Object> args, Map<String, Object> keywords, IokeObject context, IokeObject message) throws ControlFlow {
                    getArguments().getEvaluatedArguments(context, message, on, args, new HashMap<String, Object>());
                    String real = Text.getText(on);
                    List<Object> r = new ArrayList<Object>();
                    Pattern p = null;


                    if(args.size() == 0) {
                        p = new Pattern("\\s");
                    } else {
                        Object arg = args.get(0);
                        if(IokeObject.data(arg) instanceof Regexp) {
                            p = Regexp.getRegexp(arg);
                        } else {
                            String around = Text.getText(arg);
                            p = new Pattern(Pattern.quote(around));
                        }
                    }


                    RETokenizer tok = new RETokenizer(p, real);
                    tok.setEmptyEnabled(false);
                    while(tok.hasMore()) {
                        r.add(context.runtime.newText(tok.nextToken()));
                    }


                    return context.runtime.newList(r);
                }
            }));


        obj.registerMethod(obj.runtime.newNativeMethod("Takes two text arguments where the first is the substring to replace, and the second is the replacement to insert. Will only replace the first match, if any is found, and return a new Text with the result.", new TypeCheckingNativeMethod("replace") {
                private final TypeCheckingArgumentsDefinition ARGUMENTS = TypeCheckingArgumentsDefinition
                    .builder()
                    .receiverMustMimic(runtime.text)
                    .withRequiredPositional("pattern")
                    .withRequiredPositional("replacement")
                    .getArguments();


                @Override
                public TypeCheckingArgumentsDefinition getArguments() {
                    return ARGUMENTS;
                }


                @Override
                public Object activate(IokeObject self, Object on, List<Object> args, Map<String, Object> keywords, IokeObject context, IokeObject message) throws ControlFlow {
                    getArguments().getEvaluatedArguments(context, message, on, args, new HashMap<String, Object>());
                    String initial = Text.getText(on);
                    String repl = Text.getText(args.get(1));


                    Object arg = args.get(0);


                    Pattern pat = null;
                    if(IokeObject.data(arg) instanceof Regexp) {
                        pat = Regexp.getRegexp(arg);
                    } else {
                        String around = Text.getText(arg);
                        pat = new Pattern(Pattern.quote(around));
                    }


                    Replacer r = pat.replacer(repl);
                    String result = r.replaceFirst(initial);


                    return context.runtime.newText(result);
                }
            }));


        obj.registerMethod(obj.runtime.newNativeMethod("Takes two text arguments where the first is the substring to replace, and the second is the replacement to insert. Will replace all matches, if any is found, and return a new Text with the result.", new TypeCheckingNativeMethod("replaceAll") {
                private final TypeCheckingArgumentsDefinition ARGUMENTS = TypeCheckingArgumentsDefinition
                    .builder()
                    .receiverMustMimic(runtime.text)
                    .withRequiredPositional("pattern")
                    .withRequiredPositional("replacement")
                    .getArguments();


                @Override
                public TypeCheckingArgumentsDefinition getArguments() {
                    return ARGUMENTS;
                }


                @Override
                public Object activate(IokeObject self, Object on, List<Object> args, Map<String, Object> keywords, IokeObject context, IokeObject message) throws ControlFlow {
                    getArguments().getEvaluatedArguments(context, message, on, args, new HashMap<String, Object>());
                    String initial = Text.getText(on);
                    String repl = Text.getText(args.get(1));


                    Object arg = args.get(0);


                    Pattern pat = null;
                    if(IokeObject.data(arg) instanceof Regexp) {
                        pat = Regexp.getRegexp(arg);
                    } else {
                        String around = Text.getText(arg);
                        pat = new Pattern(Pattern.quote(around));
                    }


                    Replacer r = pat.replacer(repl);
                    String result = r.replace(initial);


                    return context.runtime.newText(result);
                }
            }));

public abstract class AbstractBench {
    protected void bench(String _reg, String _str, int warmup, int times) throws Exception {
        String reg = _reg;
        char[] str = _str.toCharArray();


        Pattern p = new Pattern(reg);


        System.err.println("::: /" + _reg + "/ =~ \"" + _str + "\", " + warmup + " * " + times + " times");


        for(int j=0;j<warmup;j++) {
            long before = System.currentTimeMillis();
            for(int i = 0; i < times; i++) {
                p.matcher(str,0,str.length).find();
            }
            long time = System.currentTimeMillis() - before;
            System.err.println(":  " + time + "ms");
        }
    }


    protected void benchBestOf(String _reg, String _str, int warmup, int times) throws Exception {
        String reg = _reg;
        char[] str = _str.toCharArray();


        Pattern p = new Pattern(reg);


        System.err.println("::: /" + _reg + "/ =~ \"" + _str + "\", " + warmup + " * " + times + " times");


        long best = Long.MAX_VALUE;


        for(int j=0;j<warmup;j++) {
            long before = System.currentTimeMillis();
            for(int i = 0; i < times; i++) {
                p.matcher(str,0,str.length).find();
            }
            long time = System.currentTimeMillis() - before;
            if(time < best) {
                best = time;
            }

Examples of org.jregex.Pattern

Related Classes of org.jregex.Pattern