Subversion Repositories openrisc

/* gnu/regexp/RETokenOneOf.java

   Copyright (C) 2006 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2, or (at your option)

any later version.

GNU Classpath is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

General Public License for more details.

You should have received a copy of the GNU General Public License

along with GNU Classpath; see the file COPYING.  If not, write to the

Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

02110-1301 USA.

Linking this library statically or dynamically with other modules is

making a combined work based on this library.  Thus, the terms and

conditions of the GNU General Public License cover the whole

combination.

As a special exception, the copyright holders of this library give you

permission to link this library with independent modules to produce an

executable, regardless of the license terms of these independent

modules, and to copy and distribute the resulting executable under

terms of your choice, provided that you also meet, for each linked

independent module, the terms and conditions of the license of that

module.  An independent module is a module which is not derived from

or based on this library.  If you modify this library, you may extend

this exception to your version of the library, but you are not

obligated to do so.  If you do not wish to do so, delete this

exception statement from your version. */

package gnu.java.util.regex;

import gnu.java.lang.CPStringBuilder;

import java.util.ArrayDeque;

import java.util.ArrayList;

import java.util.Deque;

import java.util.List;

final class RETokenOneOf extends REToken

{

  private final List < REToken > options;

  private boolean negative;

  // True if this RETokenOneOf is supposed to match only one character,

  // which is typically the case of a character class expression.

  private boolean matchesOneChar;

  private final List < Object > addition;

  // This ArrayList addition is used to store nested character classes.

  // For example, if the original expression is

  //    [2-7a-c[f-k][m-z]&&[^p-v][st]]

  // the basic part /2-7a-c/ is stored in the ArrayList options, and

  // the additional part /[f-k][m-z]&&[^p-v][st]/ is stored in the

  // ArrayList addition in the following order (Reverse Polish Notation):

  //           -- The matching result of the basic part is assumed here.

  //    [f-k]  -- REToken

  //    "|"    -- or

  //    [m-z]  -- REToken

  //    "|"    -- or

  //    false

  //    [^p-v] -- REToken

  //    "|"    -- or

  //    [st]   -- REToken

  //    "|"    -- or

  //    "&"    -- and

  //

  // As it is clear from the explanation above, the ArrayList addition is

  // effective only when this REToken originates from a character class

  // expression.

  // This constructor is used for convenience when we know the set beforehand,

  // e.g. \d --> new RETokenOneOf("0123456789",false, ..)

  //      \D --> new RETokenOneOf("0123456789",true, ..)

    RETokenOneOf (int subIndex, String optionsStr, boolean negative,

                  boolean insens)

  {

    super (subIndex);

    options = new ArrayList < REToken > ();

    this.negative = negative;

    for (int i = 0; i < optionsStr.length (); i++)

      options.add (new RETokenChar (subIndex, optionsStr.charAt (i), insens));

    matchesOneChar = true;

    addition = null;

  }

  RETokenOneOf (int subIndex, List < REToken > options, boolean negative)

  {

    this (subIndex, options, null, negative);

  }

  RETokenOneOf (int subIndex, List < REToken > options,

                List < Object > addition, boolean negative)

  {

    super (subIndex);

    this.options = options;

    this.addition = addition;

    this.negative = negative;

    matchesOneChar = (negative || addition != null);

  }

  int getMinimumLength ()

  {

    if (matchesOneChar)

      return 1;

    int min = Integer.MAX_VALUE;

    int x;

  for (REToken t:options)

      {

        if ((x = t.getMinimumLength ()) < min)

          min = x;

      }

    return min;

  }

  int getMaximumLength ()

  {

    if (matchesOneChar)

      return 1;

    int max = 0;

    int x;

  for (REToken t:options)

      {

        if ((x = t.getMaximumLength ()) > max)

          max = x;

      }

    return max;

  }

  boolean match (CharIndexed input, REMatch mymatch)

  {

    setHitEnd (input, mymatch);

    if (matchesOneChar)

      return matchOneChar (input, mymatch);

    else

      return matchOneRE (input, mymatch);

  }

  boolean matchOneChar (CharIndexed input, REMatch mymatch)

  {

    REMatch tryMatch;

    boolean tryOnly;

    if (addition == null)

      {

        tryMatch = mymatch;

        tryOnly = false;

      }

    else

      {

        tryMatch = (REMatch) mymatch.clone ();

        tryOnly = true;

      }

    boolean b = negative ?

      matchN (input, tryMatch, tryOnly) : matchP (input, tryMatch, tryOnly);

    if (addition == null)

      return b;

    final Deque < Boolean > stack = new ArrayDeque < Boolean > ();

    stack.push (new Boolean (b));

  for (Object obj:addition)

      {

        if (obj instanceof REToken)

          {

            b = ((REToken) obj).match (input, (REMatch) mymatch.clone ());

            stack.push (new Boolean (b));

          }

        else if (obj instanceof Boolean)

          {

            stack.push ((Boolean) obj);

          }

        else if (obj.equals ("|"))

          {

            b = stack.pop ();

            b = stack.pop () || b;

            stack.push (new Boolean (b));

          }

        else if (obj.equals ("&"))

          {

            b = stack.pop ();

            b = stack.pop () && b;

            stack.push (new Boolean (b));

          }

        else

          {

            throw new RuntimeException ("Invalid object found");

          }

      }

    if (stack.pop ())

      {

        ++mymatch.index;

        return next (input, mymatch);

      }

    return false;

  }

  private boolean matchN (CharIndexed input, REMatch mymatch, boolean tryOnly)

  {

    if (input.charAt (mymatch.index) == CharIndexed.OUT_OF_BOUNDS)

      return false;

  for (REToken tk:options)

      {

        REMatch tryMatch = (REMatch) mymatch.clone ();

        if (tk.match (input, tryMatch))

          {                     // match was successful

            return false;

          }                     // is a match

      }                         // try next option

    if (tryOnly)

      return true;

    ++mymatch.index;

    return next (input, mymatch);

  }

  private boolean matchP (CharIndexed input, REMatch mymatch, boolean tryOnly)

  {

  for (REToken tk:options)

      {

        REMatch tryMatch = (REMatch) mymatch.clone ();

        if (tk.match (input, tryMatch))

          {                     // match was successful

            if (tryOnly)

              return true;

            if (next (input, tryMatch))

              {

                mymatch.assignFrom (tryMatch);

                return true;

              }

          }

      }

    return false;

  }

  private boolean matchOneRE (CharIndexed input, REMatch mymatch)

  {

    REMatch newMatch = findMatch (input, mymatch);

    if (newMatch != null)

      {

        mymatch.assignFrom (newMatch);

        return true;

      }

    return false;

  }

  REMatch findMatch (CharIndexed input, REMatch mymatch)

  {

    if (matchesOneChar)

      return super.findMatch (input, mymatch);

    return findMatch (input, mymatch, 0);

  }

  REMatch backtrack (CharIndexed input, REMatch mymatch, Object param)

  {

    return findMatch (input, mymatch, ((Integer) param).intValue ());

  }

  private REMatch findMatch (CharIndexed input, REMatch mymatch,

                             int optionIndex)

  {

    for (int i = optionIndex; i < options.size (); i++)

      {

        REToken tk = options.get (i);

        tk = (REToken) tk.clone ();

        tk.chain (getNext ());

        REMatch tryMatch = (REMatch) mymatch.clone ();

        if (tryMatch.backtrackStack == null)

          {

            tryMatch.backtrackStack = new BacktrackStack ();

          }

        boolean stackPushed = false;

        if (i + 1 < options.size ())

          {

            tryMatch.backtrackStack.push (new BacktrackStack.

                                          Backtrack (this, input, mymatch,

                                                     i + 1));

            stackPushed = true;

          }

        if (tk.match (input, tryMatch))

          {

            return tryMatch;

          }

        if (stackPushed)

          tryMatch.backtrackStack.pop ();

      }

    return null;

  }

  boolean returnsFixedLengthMatches ()

  {

    return matchesOneChar;

  }

  int findFixedLengthMatches (CharIndexed input, REMatch mymatch, int max)

  {

    if (!matchesOneChar)

      return super.findFixedLengthMatches (input, mymatch, max);

    int numRepeats = 0;

    REMatch m = (REMatch) mymatch.clone ();

    REToken tk = (REToken) this.clone ();

    tk.chain (null);

    while (true)

      {

        if (numRepeats >= max)

          break;

        m = tk.findMatch (input, m);

        if (m == null)

          break;

        numRepeats++;

      }

    return numRepeats;

  }

  void dump (CPStringBuilder os)

  {

    os.append (negative ? "[^" : "(?:");

    for (int i = 0; i < options.size (); i++)

      {

        if (!negative && (i > 0))

          os.append ('|');

        options.get (i).dumpAll (os);

      }

    os.append (negative ? ']' : ')');

  }

}