Moved things around for rewrite of AST mechanisms

1 files changed, 70 insertions, 0 deletions

diff --git a/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTParser.java b/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTParser.java
new file mode 100644
index 0000000..db2ba98
--- /dev/null
+++ b/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTParser.java
@@ -0,0 +1,70 @@
+package bjc.dicelang.ast;
+
+import java.util.InputMismatchException;
+
+import bjc.dicelang.old.ast.nodes.IDiceASTNode;
+import bjc.dicelang.old.ast.nodes.LiteralDiceNode;
+import bjc.dicelang.old.ast.nodes.OperatorDiceNode;
+import bjc.dicelang.old.ast.nodes.VariableDiceNode;
+import bjc.utils.funcdata.IFunctionalList;
+import bjc.utils.parserutils.AST;
+import bjc.utils.parserutils.TreeConstructor;
+
+/**
+ * Parse a string expression into AST form. Doesn't do anything else
+ * 
+ * @author ben
+ *
+ */
+public class DiceASTParser {
+	/**
+	 * Create an AST from a list of tokens
+	 * 
+	 * @param tokens
+	 *            The list of tokens to convert
+	 * @return An AST built from the tokens
+	 */
+	public static AST<IDiceASTNode> createFromString(
+			IFunctionalList<String> tokens) {
+		AST<String> rawTokens =
+				TreeConstructor.constructTree(tokens, (token) -> {
+					return isOperatorNode(token);
+				}, (operator) -> false, null);
+		// The last argument is valid because there are no special
+		// operators yet, so it'll never get called
+
+		return rawTokens.rebuildTree(DiceASTParser::convertLeafNode,
+				DiceASTParser::convertOperatorNode);
+	}
+
+	private static boolean isOperatorNode(String token) {
+		try {
+			OperatorDiceNode.fromString(token);
+			return true;
+		} catch (@SuppressWarnings("unused") IllegalArgumentException iaex) {
+			// We don't care about details
+			return false;
+		}
+	}
+
+	private static IDiceASTNode convertLeafNode(String leafNode) {
+		if (LiteralDiceNode.isLiteral(leafNode)) {
+			return new LiteralDiceNode(leafNode);
+		}
+
+		return new VariableDiceNode(leafNode);
+	}
+
+	private static IDiceASTNode convertOperatorNode(String operatorNode) {
+		try {
+			return OperatorDiceNode.fromString(operatorNode);
+		} catch (IllegalArgumentException iaex) {
+			InputMismatchException imex = new InputMismatchException(
+					"Attempted to parse invalid operator " + operatorNode);
+
+			imex.initCause(iaex);
+
+			throw imex;
+		}
+	}
+}