Package jflex.core

Class RegExp

  • Direct Known Subclasses:
    RegExp1, RegExp2

    public class RegExp
    extends java.lang.Object
    Stores a regular expression of rules section in a JFlex-specification.

    This base class has no content other than its type.

    Version:
    JFlex 1.8.2
    • Field Summary

      Fields 
      Modifier and Type Field Description
      (package private) int type
      The type of the regular expression.
    • Constructor Summary

      Constructors 
      Constructor Description
      RegExp​(int type)
      Create a new regular expression of the specified type.
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      static RegExp anyChar()
      Returns a regexp that matches any character: [^]
      static RegExp1 checkPrimClass​(RegExp r)
      Confirms that the parameter is a RegExp1 of type sym.PRIMCLASS.
      boolean isCharClass()
      Find out if this regexp is a char class or equivalent to one.
      void makeCCLs​(CharClasses c, boolean caseless)
      Make character class partitions based on the classes mentioned in this regexp.
      RegExp normalise​(Macros m)
      Normalise the regular expression to eliminate macro use (expand them), and compound character class expression (compute their content).
      static IntCharSet performClassOp​(int op, IntCharSet l, IntCharSet r, RegExp ctxt)
      Performs the given set operation on the two IntCharSet parameters.
      java.lang.String print​(java.lang.String tab)
      Returns a String-representation of this regular expression with the specified indentation.
      RegExp resolveTilde()
      Recursively convert tilde (upto) expressions into negation and star.
      RegExp rev()
      Creates a new regexp that matches the reverse text of this one.
      (package private) static java.lang.String revString​(java.lang.String s)
      Reverses a string.
      int size​(Macros macros)
      The approximate number of NFA states this expression will need (only works correctly after macro expansion and without negation)
      java.lang.String toString()  
      java.lang.String typeName()
      String representation of the type of this regular expression.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Field Detail

      • type

        int type
        The type of the regular expression. This field will be filled with values from class sym.java (generated by cup)
    • Constructor Detail

      • RegExp

        public RegExp​(int type)
        Create a new regular expression of the specified type.
        Parameters:
        type - a value from the cup generated class sym.
    • Method Detail

      • print

        public java.lang.String print​(java.lang.String tab)
        Returns a String-representation of this regular expression with the specified indentation.
        Parameters:
        tab - a String that should contain only space characters and that is inserted in front of standard String-representation pf this object.
        Returns:
        a String object.
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
      • typeName

        public java.lang.String typeName()
        String representation of the type of this regular expression.
      • isCharClass

        public boolean isCharClass()
        Find out if this regexp is a char class or equivalent to one.
        Returns:
        true if the regexp is equivalent to a char class.
      • size

        public int size​(Macros macros)
        The approximate number of NFA states this expression will need (only works correctly after macro expansion and without negation)
        Parameters:
        macros - macro table for expansion
        Returns:
        a int.
      • revString

        static java.lang.String revString​(java.lang.String s)
        Reverses a string.
      • resolveTilde

        public final RegExp resolveTilde()
        Recursively convert tilde (upto) expressions into negation and star.
        Returns:
        new RegExp equivalent to the current one, but without upto expressions.
      • anyChar

        public static RegExp anyChar()
        Returns a regexp that matches any character: [^]
        Returns:
        the regexp for [^]
      • checkPrimClass

        public static RegExp1 checkPrimClass​(RegExp r)
        Confirms that the parameter is a RegExp1 of type sym.PRIMCLASS.
        Parameters:
        r - the RegExp to check
        Returns:
        r cast to RegExp1
        Throws:
        CharClassException - if r is not a RegExp1 or of type sym.PRIMCLASS.
      • performClassOp

        public static IntCharSet performClassOp​(int op,
                                                IntCharSet l,
                                                IntCharSet r,
                                                RegExp ctxt)
        Performs the given set operation on the two IntCharSet parameters.
        Parameters:
        op - the operation to perform (as @{link sym} constant)
        l - the left operator of the expression
        r - the right operator of the expression
        ctxt - the regular expression containing the provided operator
        Returns:
        a new IntCharSet
        Throws:
        RegExpException - for ctxt if the operator is not supported
      • normalise

        public final RegExp normalise​(Macros m)
        Normalise the regular expression to eliminate macro use (expand them), and compound character class expression (compute their content).
        Returns:
        a regexp that contains only IntCharSet char classes and no sym.MACROUSE.
      • makeCCLs

        public final void makeCCLs​(CharClasses c,
                                   boolean caseless)
        Make character class partitions based on the classes mentioned in this regexp.

        Assumption: regexp is normalised.

      • rev

        public final RegExp rev()
        Creates a new regexp that matches the reverse text of this one.
        Returns:
        the reverse regexp