1 files changed, 78 insertions, 0 deletions
diff --git a/JPratt/src/main/java/bjc/pratt/blocks/ChainParseBlock.java b/JPratt/src/main/java/bjc/pratt/blocks/ChainParseBlock.java
new file mode 100644
index 0000000..5c728d9
--- /dev/null
+++ b/JPratt/src/main/java/bjc/pratt/blocks/ChainParseBlock.java
@@ -0,0 +1,78 @@
+package bjc.pratt.blocks;
+
+import java.util.Set;
+
+import bjc.pratt.ParserContext;
+import bjc.pratt.tokens.Token;
+import bjc.utils.data.ITree;
+import bjc.utils.data.Tree;
+import bjc.utils.parserutils.ParserException;
+
+/**
+ * A {@link ParseBlock} for a series of parse blocks, linked by a set of tokens.
+ * 
+ * Roughly analogous to Perl 6s list associative operators.
+ * 
+ * @author bjculkin
+ * 
+ * @param <K>
+ *                The token key type.
+ * 
+ * @param <V>
+ *                The token value type.
+ * 
+ * @param <C>
+ *                The parser state type.
+ *
+ */
+public class ChainParseBlock<K, V, C> implements ParseBlock<K, V, C> {
+	private ParseBlock<K, V, C> iner;
+
+	private Set<K> indicators;
+
+	private Token<K, V> trm;
+
+	/**
+	 * Create a new chain parser block.
+	 * 
+	 * @param inner
+	 *                The block for the chains interior.
+	 * 
+	 * @param chainIndicators
+	 *                The set of markers that indicate continuing the chain
+	 * 
+	 * @param term
+	 *                The node in the AST for the expression.
+	 */
+	public ChainParseBlock(ParseBlock<K, V, C> inner, Set<K> chainIndicators, Token<K, V> term) {
+		iner = inner;
+		indicators = chainIndicators;
+		trm = term;
+	}
+
+	@Override
+	public ITree<Token<K, V>> parse(ParserContext<K, V, C> ctx) throws ParserException {
+		ITree<Token<K, V>> expression = iner.parse(ctx);
+
+		Token<K, V> currentToken = ctx.tokens.current();
+		if (indicators.contains(currentToken.getKey())) {
+			ITree<Token<K, V>> res = new Tree<>(trm);
+			res.addChild(expression);
+
+			while (indicators.contains(currentToken.getKey())) {
+				res.addChild(new Tree<>(currentToken));
+				ctx.tokens.next();
+
+				ITree<Token<K, V>> innerExpression = iner.parse(ctx);
+				res.addChild(innerExpression);
+
+				currentToken = ctx.tokens.current();
+			}
+
+			return res;
+		}
+
+		return expression;
+	}
+
+}