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  1. import java.util.*;
  2. import java.util.regex.*;
  3. import java.lang.*;
  4. import java.io.*;
  5.  
  6. /* Name of the class has to be "Main" only if the class is public. */
  7. class Ideone
  8. {
  9. 	// All rules never end with WhiteSpace. This allows us to check for error easier.
  10.  
  11.     final static String Identifier = "\\p{javaJavaIdentifierStart}\\p{javaJavaIdentifierPart}*+";
  12.     // Heuristic to exclude any position where adding space would split an Identifier or a keyword apart
  13.     final static String TokenBoundary = "(?:(?<!\\p{javaJavaIdentifierPart})|(?!\\p{javaJavaIdentifierPart}))";
  14.  
  15.     // Optional whitespace
  16.     final static String WhiteSpaceOpt = "[ \\t\\f\\r\\n]*+";
  17.     // Compulsory whitespace
  18.     final static String WhiteSpaceCom = "[ \\t\\f\\r\\n]++";
  19.  
  20.     final static String MarkerAnnotation = "@" + WhiteSpaceOpt + Identifier;
  21.     // Skipped: SingleElementAnnotation, NormalAnnotation
  22.     // Can't be included due to middle recursion
  23.     final static String Annotation = MarkerAnnotation;
  24.  
  25.     final static String ClassModifier = "(?:public|protected|private|abstract|static|final|strictfp|" + Annotation + ")";
  26.     // Since the declaration
  27.     //     public@Deprecated ...
  28.     // is allowed, the space between modifiers is optional.
  29.     // Since allowing the space to be optional recognizes this invalid declaration
  30.     //     publicstatic ...
  31.     // we need to assert boundary between 2 class modifiers
  32.     final static String ClassModifiers = ClassModifier + "(?:" + WhiteSpaceOpt + TokenBoundary + ClassModifier + ")*+";
  33.  
  34.     final static String TypeVariable = Identifier;
  35.  
  36.     // Skipped: ArrayType, ClassOrInterfaceType
  37.     // Can't be included, since the grammar is context-free, and this is where middle recursion occurs
  38.     final static String ReferenceType = TypeVariable;
  39.     final static String WildcardBounds = "(?:extends|super)" + WhiteSpaceCom + ReferenceType;
  40.     final static String Wildcard = "[?]" + WhiteSpaceOpt + "(?:" + WildcardBounds + ")?+";
  41.     final static String TypeArgument = "(?:" + ReferenceType + "|" + Wildcard + ")";
  42.     final static String TypeArgumentList = TypeArgument + "(?:" + WhiteSpaceOpt + "," + WhiteSpaceOpt + TypeArgument + ")*+";
  43.     final static String TypeArguments = "<" + WhiteSpaceOpt + TypeArgumentList + WhiteSpaceOpt + ">";
  44.  
  45.     final static String TypeName = Identifier + "(?:" + WhiteSpaceOpt + "[.]" + WhiteSpaceOpt + Identifier + ")*+";
  46.     // Expanded definition of ClassOrInterfaceType = ClassType = InterfaceType
  47.     //     ClassOrInterfaceType -> TypeName  TypeArguments<opt>
  48.     //     ClassOrInterfaceType -> ClassOrInterfaceType . Identifier TypeArguments<opt>
  49.     final static String ClassType = TypeName + "(?:" + WhiteSpaceOpt + TypeArguments + ")?+" + 
  50.         "(?:" + WhiteSpaceOpt + "[.]" + WhiteSpaceOpt + Identifier + "(?:" + WhiteSpaceOpt + TypeArguments + ")?+" + ")*+";
  51.     // Definition of ClassType and InterfaceType are identical
  52.     final static String InterfaceType = ClassType;
  53.     final static String ClassOrInterfaceType = ClassType;
  54.  
  55.     final static String TypeBound = "extends" + WhiteSpaceCom + "(?:" + ClassOrInterfaceType + "|" + TypeVariable + ")";
  56.     final static String TypeParameter = TypeVariable + "(?:" + WhiteSpaceCom + TypeBound + ")?+";
  57.     final static String TypeParameterList = TypeParameter + "(?:" + WhiteSpaceOpt + "," + WhiteSpaceOpt + TypeParameter + ")*+";
  58.     final static String TypeParameters = "<" + WhiteSpaceOpt + TypeParameterList + WhiteSpaceOpt + ">";
  59.  
  60.     final static String Super = "extends" + WhiteSpaceCom + ClassType;
  61.  
  62.     final static String InterfaceTypeList = InterfaceType + "(?:" + WhiteSpaceOpt  + "," + WhiteSpaceOpt + InterfaceType + ")*+";
  63.     final static String Interfaces = "implements" + WhiteSpaceCom + InterfaceTypeList;
  64.  
  65.     final static String NormalClassDeclaration =
  66.         // Annotation in its fullest form can end in ), so WhiteSpaceOpt is used here for pedantic
  67.         // It can be changed to WhiteSpaceCom to save the TokenBoundary check, since current definition always end with Identifier character
  68.         "(?:" + "(" + ClassModifiers + ")" + WhiteSpaceOpt + ")?+" +
  69.         TokenBoundary + "class" + WhiteSpaceCom +
  70.         // WhiteSpaceOpt is used here, since TypeParameters starts with < and no whitespace is needed to delimit
  71.         "(" + Identifier + ")" + WhiteSpaceOpt + 
  72.         "(?:" + "(" + TypeParameters + ")" + WhiteSpaceOpt + ")?+" +
  73.         // As the result, we need to check for boundary before "extends" and "implements"
  74.         TokenBoundary + "(?:" + "(" + Super + ")"+ WhiteSpaceOpt + ")?+" +
  75.         TokenBoundary + "(?:" + "(" + Interfaces + WhiteSpaceOpt + ")" + ")?+[{]";
  76.         // ClassBody is skipped, and only opening bracket { is matched
  77.  
  78.     final static String InterfaceModifier = "(?:public|protected|private|abstract|static|strictfp|" + Annotation + ")";
  79.     // Same as ClassModifiers, except that "final" is no longer a valid modifier
  80.     final static String InterfaceModifiers = InterfaceModifier + "(?:" + WhiteSpaceOpt + TokenBoundary + InterfaceModifier + ")*+";
  81.  
  82.     final static String ExtendsInterfaces = "extends" + WhiteSpaceCom + InterfaceTypeList;
  83.  
  84.     final static String NormalInterfaceDeclaration = 
  85.         "(?:" + "(" + InterfaceModifiers + ")" + WhiteSpaceOpt + ")?+" +
  86.         TokenBoundary + "interface" + WhiteSpaceCom +
  87.         // WhiteSpaceOpt is used here, since TypeParameters starts with < and no whitespace is needed to delimit
  88.         "(" + Identifier + ")" + WhiteSpaceOpt + 
  89.         "(?:" + "(" + TypeParameters + ")" + WhiteSpaceOpt + ")?+" +
  90.         // As the result, we need to check for boundary before "extends" here
  91.         TokenBoundary + "(?:" + "(" + ExtendsInterfaces + ")" + WhiteSpaceOpt + ")?+[{]";
  92.  
  93.  
  94. 	public static void main (String[] args) throws java.lang.Exception
  95. 	{
  96. 		String sources[] = {
  97. 			"class SetupMouseListener extends MouseAdapter {}",
  98. 			"abstract class X<B extends Integer,D extends java.io.InputStream,R extends Comparator<?super D>>extends java.util.ArrayList<Integer>implements java.util.Queue<Integer>,Serializable{}"
  99. 			};
  100.  
  101. 		Pattern re = Pattern.compile(NormalClassDeclaration);
  102.  
  103. 		Matcher m;
  104.  
  105. 		for (String source: sources) {
  106. 			m = re.matcher(source);
  107.  
  108. 			if (m.find()) {
  109. 				for (int i = 1; i <= m.groupCount(); i++) {
  110. 					System.out.println(m.group(i));
  111. 				}
  112. 			}
  113. 		}
  114. 	}
  115. }
Success #stdin #stdout 0.09s 380480KB
comments (?)
stdin 
Standard input is empty
stdout 
null
SetupMouseListener
null
extends MouseAdapter
null
abstract
X
<B extends Integer,D extends java.io.InputStream,R extends Comparator<?super D>>
extends java.util.ArrayList<Integer>
implements java.util.Queue<Integer>,Serializable
https://ideone.com/jzdZUF
language:
Java (HotSpot 12)
created:
9 years ago
visibility:
public

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