1 files changed, 114 insertions, 0 deletions
diff --git a/sources/scalac/util/PrefixMatcher.java b/sources/scalac/util/PrefixMatcher.java
new file mode 100644
index 0000000000..1b0acd8d7a
--- /dev/null
+++ b/sources/scalac/util/PrefixMatcher.java
@@ -0,0 +1,114 @@
+/*     ____ ____  ____ ____  ______                                     *\
+**    / __// __ \/ __// __ \/ ____/    SOcos COmpiles Scala             **
+**  __\_ \/ /_/ / /__/ /_/ /\_ \       (c) 2002, LAMP/EPFL              **
+** /_____/\____/\___/\____/____/                                        **
+\*                                                                      */
+
+// $Id$
+
+package scalac.util;
+
+import java.util.Map;
+import java.util.HashMap;
+import java.util.List;
+import java.util.ArrayList;
+
+public class PrefixMatcher {
+
+    public static class Entry {
+
+        private Entry prev;
+        private Entry next;
+
+        public final String key;
+        public final Object value;
+        public final String argument;
+        public final String description;
+
+        public Entry(String key, Object value, String argument,
+            String description)
+        {
+            this.key = key;
+            this.value = value;
+            this.argument = argument;
+            this.description = description;
+        }
+    }
+
+    private final Map entries;
+    private Entry first;
+    private Entry last;
+
+    public PrefixMatcher() {
+        this.entries = new HashMap();
+    }
+
+    public void insert(String key, Object value) {
+        insert(key, value, null, null);
+    }
+
+    public void insert(String key, Object value, String description) {
+        insert(key, value, null, description);
+    }
+
+    public void insert(String key, Object value, String argument,
+        String description)
+    {
+        assert key != null && !entries.containsKey(key) : key;
+        Entry entry = new Entry(key, value, argument, description);
+        if (first == null) {
+            first = last = entry;
+        } else {
+            last.next = entry;
+            entry.prev = last;
+            last = entry;
+        }
+        entries.put(key, entry);
+    }
+
+    public Entry[] lookup(String key) {
+        Object value = entries.get(key);
+        if (value != null) return new Entry[] { (Entry)value };
+        List list = new ArrayList();
+        for (Entry i = first; i != null; i = i.next) {
+            if (i.key.startsWith(key)) list.add(i);
+        }
+        return (Entry[])list.toArray(new Entry[list.size()]);
+    }
+
+    public String getErrorMessage(String key, Entry[] entries, String what) {
+        switch (entries.length) {
+        case 0:
+            return "unknown " + what + " '" + key + "'";
+        case 1:
+            return null;
+        case 2:
+            return "ambigous " + what + " '" + key + "', both '" +
+                entries[0].key + "' and '" + entries[1].key  + "' match";
+        default:
+            StringBuffer buffer = new StringBuffer();
+            buffer.append("ambigous ").append(what);
+            buffer.append(" '").append(key).append("'");
+            for (int i = 0; i < entries.length; i++) {
+                buffer.append(i < entries.length - 1 ? ", " : " and ");
+                buffer.append('\'').append(entries[i].key).append('\'');
+            }
+            buffer.append(" match");
+            return buffer.toString();
+        }
+    }
+
+    public List getHelpStrings(String separator1, String separator2) {
+        List strings = new ArrayList();
+        for (Entry entry = first; entry != null; entry = entry.next) {
+            if (entry.description != null)
+                if (entry.argument != null)
+                    strings.add(entry.key + separator1 + entry.argument +
+                        separator2 + entry.description);
+                else
+                    strings.add(entry.key + separator2 + entry.description);
+        }
+        return strings;
+    }
+
+}