Merge branch 'master' of https://github.com/bculkin2442/JPratt.git

1 files changed, 81 insertions, 0 deletions

diff --git a/JPratt/src/main/java/bjc/pratt/blocks/GrammarParseBlock.java b/JPratt/src/main/java/bjc/pratt/blocks/GrammarParseBlock.java
new file mode 100644
index 0000000..6bf5582
--- /dev/null
+++ b/JPratt/src/main/java/bjc/pratt/blocks/GrammarParseBlock.java
@@ -0,0 +1,81 @@
+package bjc.pratt.blocks;
+
+import java.util.function.Function;
+
+import bjc.pratt.ParserContext;
+import bjc.pratt.PrattParser;
+import bjc.pratt.tokens.Token;
+import bjc.pratt.tokens.TokenStream;
+import bjc.utils.data.ITree;
+import bjc.utils.funcutils.Isomorphism;
+import bjc.utils.parserutils.ParserException;
+
+/**
+ * A {@link ParseBlock} that parses an expression from a 'inner' grammar.
+ *
+ * @author bjculkin
+ *
+ * @param <K>
+ *                The key type of the outer tokens.
+ *
+ * @param <V>
+ *                The value type of the outer tokens.
+ *
+ * @param <C>
+ *                The state type of the outer parser.
+ *
+ * @param <K2>
+ *                The key type of the inner tokens.
+ *
+ * @param <V2>
+ *                The value type of the inner tokens.
+ *
+ * @param <C2>
+ *                The state type of the outer parser.
+ */
+public class GrammarParseBlock<K, V, C, K2, V2, C2> implements ParseBlock<K, V, C> {
+	private final PrattParser<K2, V2, C2> innr;
+
+	private final int	prcedence;
+	private final boolean	isStatemnt;
+
+	private final Function<TokenStream<K, V>, TokenStream<K2, V2>>		tkenTransform;
+	private final Isomorphism<C, C2>					stteTransform;
+	private final Function<ITree<Token<K2, V2>>, ITree<Token<K, V>>>	xpressionTransform;
+
+	/**
+	 * Create a new grammar parser block.
+	 *
+	 * @param inner
+	 * @param precedence
+	 * @param isStatement
+	 * @param tokenTransform
+	 * @param stateTransform
+	 * @param expressionTransform
+	 */
+	public GrammarParseBlock(final PrattParser<K2, V2, C2> inner, final int precedence, final boolean isStatement,
+			final Function<TokenStream<K, V>, TokenStream<K2, V2>> tokenTransform,
+			final Isomorphism<C, C2> stateTransform,
+			final Function<ITree<Token<K2, V2>>, ITree<Token<K, V>>> expressionTransform) {
+		innr = inner;
+		prcedence = precedence;
+		isStatemnt = isStatement;
+		tkenTransform = tokenTransform;
+		stteTransform = stateTransform;
+		xpressionTransform = expressionTransform;
+	}
+
+	@Override
+	public ITree<Token<K, V>> parse(final ParserContext<K, V, C> ctx) throws ParserException {
+		final C2 newState = stteTransform.to(ctx.state);
+
+		final TokenStream<K2, V2> newTokens = tkenTransform.apply(ctx.tokens);
+
+		final ITree<Token<K2, V2>> expression = innr.parseExpression(prcedence, newTokens, newState,
+				isStatemnt);
+
+		ctx.state = stteTransform.from(newState);
+
+		return xpressionTransform.apply(expression);
+	}
+}
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