Reimplement AbbrevMap, and implement Multimap

This reimplements the old AbbrevMap structure as AbbrevMap2, and created
a new Multimap structure as a apart of it.

Multimap is exactly what it sounds like; a map that allows multiple
values for a given key. The only real thing that is different about it,
is that if you add a key-value pair multiple times, you'll have to
remove it multiple times.

1 files changed, 93 insertions, 0 deletions

diff --git a/src/main/java/bjc/esodata/AbbrevMap2.java b/src/main/java/bjc/esodata/AbbrevMap2.java
new file mode 100644
index 0000000..f79a2d2
--- /dev/null
+++ b/src/main/java/bjc/esodata/AbbrevMap2.java
@@ -0,0 +1,93 @@
+package bjc.esodata;
+
+import java.util.*;
+
+/**
+ * A revised version of {@link AbbrevMap}
+ *
+ * @author Ben Culkin
+ */
+public class AbbrevMap2 {
+	// Stores a mapping from strings, to strings that they could be abbreviations for
+	private Multimap<String, String> backing;
+
+	/**
+	 * Create a new abbreviation map.
+	 */
+	public AbbrevMap2() {
+		backing = new Multimap<>();
+	}
+
+	/**
+	 * Add words to the map.
+	 *
+	 * @param words
+	 * 	The words to add to the map.
+	 */
+	public void add(String... words) {
+		for (String word : words) {
+			for (String substr : genAbbrevs(word)) {
+				backing.add(substr, word);
+			}
+		}
+	}
+
+	// Generate all of the strings a given word could be abbreviated as
+	private List<String> genAbbrevs(String word) {
+		List<String> retList = new ArrayList<>();
+
+		int len = word.length();
+
+		for (int i = 1; i <= len; i++) {
+			String substr = word.substring(0, i);
+
+			retList.add(substr);
+		}
+
+		return retList;
+	}
+
+	/**
+	 * Remove words from the map.
+	 *
+	 * @param words
+	 * 	The words to remove from the map.
+	 */
+	public void removeWords(String... words) {
+		for (String word : words) {
+			for (String substr : genAbbrevs(word)) {
+				backing.remove(substr, word);
+			}
+		}
+	}
+
+	/**
+	 * Get all of the strings that a string could be an abbreviation for.
+	 *
+	 * @param word
+	 * 	The word to attempt to deabbreviate.
+	 *
+	 * @return All of the possible deabbreviations for that word.
+	 */
+	public Set<String> deabbrevAll(String word) {
+		return backing.get(word);
+	}
+
+	/**
+	 * Get the unambiguous thing the string is an abbreviation for.
+	 *
+	 * @param word
+	 * 	The word to attempt to deabbreviate.
+	 *
+	 * @return The unambiguous deabbreviation of the string, or null if there isn't one.
+	 */
+	public String deabbrev(String word) {
+		Set<String> st = backing.get(word);
+
+		if (st.size() == 1) {
+			return st.iterator().next();
+		} else {
+			return null;
+		}
+	}
+}