Refactor to add backtracking support

This probably doesn't help w/ error messages, but it enables some cool
ideas where syntax can be reused in cases where it would otherwise be
invalid

1 files changed, 39 insertions, 0 deletions

diff --git a/JPratt/src/main/java/bjc/pratt/commands/impls/PanfixCommand.java b/JPratt/src/main/java/bjc/pratt/commands/impls/PanfixCommand.java
new file mode 100644
index 0000000..06e69c1
--- /dev/null
+++ b/JPratt/src/main/java/bjc/pratt/commands/impls/PanfixCommand.java
@@ -0,0 +1,39 @@
+package bjc.pratt.commands.impls;
+
+import bjc.data.SimpleTree;
+import bjc.data.Tree;
+import bjc.pratt.ParserContext;
+import bjc.pratt.commands.CommandResult;
+import bjc.pratt.commands.InitialCommand;
+import bjc.pratt.commands.CommandResult.Status;
+import bjc.pratt.tokens.Token;
+import bjc.utils.parserutils.ParserException;
+
+public final class PanfixCommand<K, V, C> implements InitialCommand<K, V, C> {
+	private final Token<K, V> marker;
+	private final K term;
+	private final int precedence;
+
+	public PanfixCommand(Token<K, V> marker, K term, int precedence) {
+		this.marker = marker;
+		this.term = term;
+		this.precedence = precedence;
+	}
+
+	@Override
+	public CommandResult<K, V> denote(Token<K, V> operator, ParserContext<K, V, C> ctx) throws ParserException {
+		CommandResult<K,V> resLeftSide = ctx.parse.parseExpression(precedence + 1, ctx.tokens, ctx.state, false);
+		if (resLeftSide.status != Status.SUCCESS) return resLeftSide;
+		Tree<Token<K, V>> leftSide = resLeftSide.success();
+		ctx.tokens.expect(term);
+		ctx.tokens.next();
+		
+		CommandResult<K, V> resRightSide = ctx.parse.parseExpression(precedence + 1, ctx.tokens, ctx.state, false);
+		if (resLeftSide.status != Status.SUCCESS) return resRightSide;
+		Tree<Token<K,V>> rightSide = resRightSide.success();
+		ctx.tokens.expect(term);
+		ctx.tokens.next();
+		
+		return CommandResult.success(new SimpleTree<>(marker, leftSide, rightSide));
+	}
+}
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