/* * KeywordMap.java - Fast keyword->id map * Copyright (C) 1998, 1999 Slava Pestov * Copyright (C) 1999 Mike Dillon * * You may use and modify this package for any purpose. Redistribution is * permitted, in both source and binary form, provided that this notice * remains intact in all source distributions of this package. */ package processing.app.syntax; import javax.swing.text.Segment; /** * A KeywordMap is similar to a hashtable in that it maps keys * to values. However, the `keys' are Swing segments. This allows lookups of * text substrings without the overhead of creating a new string object. *

* This class is used by CTokenMarker to map keywords to ids. * * @author Slava Pestov, Mike Dillon * @version $Id: KeywordMap.java,v 1.1 2005/04/09 02:30:37 benfry Exp $ */ public class KeywordMap { /** * Creates a new KeywordMap. * @param ignoreCase True if keys are case insensitive */ public KeywordMap(boolean ignoreCase) { this(ignoreCase, 52); this.ignoreCase = ignoreCase; } /** * Creates a new KeywordMap. * @param ignoreCase True if the keys are case insensitive * @param mapLength The number of `buckets' to create. * A value of 52 will give good performance for most maps. */ public KeywordMap(boolean ignoreCase, int mapLength) { this.mapLength = mapLength; this.ignoreCase = ignoreCase; map = new Keyword[mapLength]; } /** * Looks up a key. * @param text The text segment * @param offset The offset of the substring within the text segment * @param length The length of the substring */ public byte lookup(Segment text, int offset, int length) { if(length == 0) return Token.NULL; Keyword k = map[getSegmentMapKey(text, offset, length)]; while(k != null) { if(length != k.keyword.length) { k = k.next; continue; } if(SyntaxUtilities.regionMatches(ignoreCase,text,offset, k.keyword)) return k.id; k = k.next; } return Token.NULL; } /** * Adds a key-value mapping. * @param keyword The key * @Param id The value */ public void add(String keyword, byte id) { int key = getStringMapKey(keyword); map[key] = new Keyword(keyword.toCharArray(),id,map[key]); } /** * Returns true if the keyword map is set to be case insensitive, * false otherwise. */ public boolean getIgnoreCase() { return ignoreCase; } /** * Sets if the keyword map should be case insensitive. * @param ignoreCase True if the keyword map should be case * insensitive, false otherwise */ public void setIgnoreCase(boolean ignoreCase) { this.ignoreCase = ignoreCase; } // protected members protected int mapLength; protected int getStringMapKey(String s) { return (Character.toUpperCase(s.charAt(0)) + Character.toUpperCase(s.charAt(s.length()-1))) % mapLength; } protected int getSegmentMapKey(Segment s, int off, int len) { return (Character.toUpperCase(s.array[off]) + Character.toUpperCase(s.array[off + len - 1])) % mapLength; } // private members class Keyword { public Keyword(char[] keyword, byte id, Keyword next) { this.keyword = keyword; this.id = id; this.next = next; } public char[] keyword; public byte id; public Keyword next; } private Keyword[] map; private boolean ignoreCase; }