Merge branch 'master' of https://github.com/bculkin2442/bjc-utils2

1 files changed, 41 insertions, 0 deletions

diff --git a/base/src/main/java/bjc/utils/patterns/SimplePatternMatcher.java b/base/src/main/java/bjc/utils/patterns/SimplePatternMatcher.java
new file mode 100644
index 0000000..fea947a
--- /dev/null
+++ b/base/src/main/java/bjc/utils/patterns/SimplePatternMatcher.java
@@ -0,0 +1,41 @@
+package bjc.utils.patterns;
+
+import bjc.data.*;
+
+/**
+ * Implements pattern-matching (of a sort) against a collection of patterns.
+ * 
+ * @author Ben Culkin
+ * 
+ * @param <ReturnType> The type returned by the pattern.
+ */
+public class SimplePatternMatcher<ReturnType, InputType>
+	implements PatternMatcher<ReturnType, InputType> {
+	private final ComplexPattern<ReturnType, Object, InputType>[] patterns;
+	
+	/**
+	 * Create a new pattern matcher.
+	 * 
+	 * @param patterns The set of patterns to match against.
+	 */
+	@SuppressWarnings("unchecked")
+	@SafeVarargs
+	public SimplePatternMatcher(ComplexPattern<ReturnType, ?, InputType>...patterns) {
+		// Note: this may seem a somewhat questionable cast, but because we never
+		// actually do anything with the value who has a type matching the second
+		// parameter, this should be safe
+		this.patterns = (ComplexPattern<ReturnType, Object, InputType>[]) patterns;
+	}
+
+	@Override
+	public ReturnType matchFor(InputType input) throws NonExhaustiveMatch {
+		for (ComplexPattern<ReturnType, Object, InputType> pattern : patterns) {
+			Pair<Boolean, Object> matches = pattern.matches(input);
+			if (matches.getLeft()) {
+				pattern.apply(input, matches.getRight());
+			}
+		}
+		
+		throw new NonExhaustiveMatch("Non-exhaustive match against " + input);
+	}
+}