1 files changed, 98 insertions, 0 deletions
diff --git a/JPratt/src/main/java/com/ashardalon/pratt/blocks/ParseBlocks.java b/JPratt/src/main/java/com/ashardalon/pratt/blocks/ParseBlocks.java
new file mode 100644
index 0000000..89989fd
--- /dev/null
+++ b/JPratt/src/main/java/com/ashardalon/pratt/blocks/ParseBlocks.java
@@ -0,0 +1,98 @@
+package com.ashardalon.pratt.blocks;
+
+import java.util.function.Predicate;
+import java.util.function.UnaryOperator;
+
+import com.ashardalon.pratt.tokens.Token;
+
+import bjc.data.Tree;
+
+/**
+ * Utility class for creating common implementations of {@link ParseBlock}
+ *
+ * @author bjculkin
+ *
+ */
+public class ParseBlocks {
+	/*
+	 * Grammar parse blocks are complex enough to not get a builder method.
+	 */
+
+	/**
+	 * Create a new repeating parse block.
+	 *
+	 * @param <K> The key type for the tokens. 
+	 * @param <V> The value type for the tokens.
+	 * @param <C> The context type for the tokens.
+	 *
+	 * @param inner
+	 *        The parse block to repeat.
+	 *
+	 * @param delim
+	 *        The token type that separates repetitions.
+	 *
+	 * @param term
+	 *        The token type that terminates repetitions.
+	 *
+	 * @param mark
+	 *        The token to use as the node in the AST.
+	 *
+	 * @param action
+	 *        The action to perform on the state after every repetition.
+	 *
+	 * @return A configured repeating parse block.
+	 */
+	public static <K, V, C> ParseBlock<K, V, C> repeating(final ParseBlock<K, V, C> inner, final K delim,
+			final K term, final Token<K, V> mark, final UnaryOperator<C> action) {
+		return new RepeatingParseBlock<>(inner, delim, term, mark, action);
+	}
+
+	/**
+	 * Create a new triggered parse block.
+	 *
+	 * @param <K> The key type for the tokens. 
+	 * @param <V> The value type for the tokens.
+	 * @param <C> The context type for the tokens.
+	 *
+	 * @param source
+	 *        The block to trigger around.
+	 *
+	 * @param onEnter
+	 *        The action to perform upon the state before entering the
+	 *        block.
+	 *
+	 * @param onExit
+	 *        The action to perform upon the state after exiting the block.
+	 *
+	 * @return A configured trigger parse block.
+	 */
+	public static <K, V, C> ParseBlock<K, V, C> trigger(final ParseBlock<K, V, C> source,
+			final UnaryOperator<C> onEnter, final UnaryOperator<C> onExit) {
+		return new TriggeredParseBlock<>(onEnter, onExit, source);
+	}
+
+	/**
+	 * Create a new simple parse block.
+	 *
+	 * @param <K> The key type for the tokens. 
+	 * @param <V> The value type for the tokens.
+	 * @param <C> The context type for the tokens.
+	 *
+	 * @param precedence
+	 *        The precedence of the expression inside the block.
+	 *
+	 * @param terminator
+	 *        The key type of the token expected after this block, or null
+	 *        if none is expected.
+	 *
+	 * @param validator
+	 *        The predicate to use to validate parsed expressions, or null
+	 *        if none is used.
+	 *
+	 * @return A configured simple parse block.
+	 */
+	public static <K, V, C> ParseBlock<K, V, C> simple(final int precedence, final K terminator,
+			final Predicate<Tree<Token<K, V>>> validator) {
+		return new SimpleParseBlock<>(precedence, validator, terminator);
+	}
+}
+\ No newline at end of file