1 files changed, 242 insertions, 0 deletions
diff --git a/src/main/java/bjc/dicelang/scl/StreamEngine.java b/src/main/java/bjc/dicelang/scl/StreamEngine.java
new file mode 100644
index 0000000..59c2121
--- /dev/null
+++ b/src/main/java/bjc/dicelang/scl/StreamEngine.java
@@ -0,0 +1,242 @@
+package bjc.dicelang.scl;
+
+import bjc.utils.esodata.SingleTape;
+import bjc.utils.esodata.Tape;
+import bjc.utils.esodata.TapeLibrary;
+import bjc.utils.funcdata.FunctionalList;
+import bjc.utils.funcdata.FunctionalMap;
+import bjc.utils.funcdata.IList;
+import bjc.utils.funcdata.IMap;
+import bjc.utils.funcutils.ListUtils;
+
+import java.util.Arrays;
+import java.util.function.Predicate;
+
+import static bjc.dicelang.scl.Errors.ErrorKey.*;
+
+/**
+ * Implements multiple interleaved parse streams, as well as a command language
+ * for the streams.
+ *
+ * The idea for the interleaved streams came from the language Oozylbub &amp;
+ * Murphy, but the command language was my own idea.
+ *
+ * @author Ben Culkin
+ */
+public class StreamEngine {
+	/**
+	 * Whether or not we're doing debugging.
+	 */
+	public final boolean debug = true;
+
+	/* Our streams. */
+	Tape<IList<String>> streams;
+	IList<String> currStream;
+
+	/* Saved streams */
+	TapeLibrary<IList<String>> savedStreams;
+
+	/* Handler for SCL programs */
+	private final StreamControlEngine scleng;
+
+	private static IMap<Character, Predicate<StreamEngine>> commands;
+
+	static {
+		commands = new FunctionalMap<>();
+
+		commands.put('+', (eng) -> {
+			eng.newStream();
+			return true;
+		});
+
+		commands.put('>', (eng) -> eng.rightStream());
+		commands.put('<', (eng) -> eng.leftStream());
+		commands.put('-', (eng) -> eng.deleteStream());
+		commands.put('M', (eng) -> eng.mergeStream());
+		commands.put('L', (eng) -> {
+			String[] arr = eng.currStream.toArray(new String[0]);
+
+			boolean succ = eng.scleng.runProgram(arr);
+
+			return succ;
+		});
+	}
+
+	/**
+	 * Create a new stream engine.
+	 *
+	 */
+	public StreamEngine() {
+		savedStreams = new TapeLibrary<>();
+		scleng = new StreamControlEngine(this);
+	}
+
+	/* Do pre-run (re)initialization. */
+	private void init() {
+		/* Reinitialize our list of streams. */
+		streams = new SingleTape<>();
+
+		/* Create an initial stream. */
+		currStream = new FunctionalList<>();
+		streams.insertBefore(currStream);
+	}
+
+	/**
+	 * Process a possibly interleaved set of streams.
+	 *
+	 * @param toks
+	 *        The raw token to read streams from.
+	 *
+	 * @param dest
+	 *        The list to write the final stream to.
+	 *
+	 * @return Whether or not the streams were successfully processed.
+	 */
+	public boolean doStreams(final String[] toks, final IList<String> dest) {
+		return doStreams(Arrays.asList(toks), dest);
+	}
+
+	/**
+	 * Process a possibly interleaved set of streams.
+	 *
+	 * @param toks
+	 *        The raw token to read streams from.
+	 *
+	 * @param dest
+	 *        The list to write the final stream to.
+	 *
+	 * @return Whether or not the streams were successfully processed.
+	 */
+	public boolean doStreams(final Iterable<String> toks, final IList<String> dest) {
+		/* Initialize per-run state. */
+		init();
+
+		/* Are we currently quoting things? */
+		boolean quoteMode = false;
+
+		/* Process each token. */
+		for(final String tk : toks) {
+			/* Process stream commands. */
+			if(tk.startsWith("{@S") && !quoteMode) {
+				if(tk.equals("{@SQ}")) {
+					/* Start quoting. */
+					quoteMode = true;
+				} else if(!processCommand(tk)) {
+					return false;
+				}
+			} else {
+				if(tk.equals("{@SU}")) {
+					/* Stop quoting. */
+					quoteMode = false;
+				} else if(tk.startsWith("\\") && tk.endsWith("{@SU}")) {
+					/* Unquote quoted end. */
+					currStream.add(tk.substring(1));
+				} else {
+					currStream.add(tk);
+				}
+			}
+		}
+
+		for(final String tk : currStream) {
+			/* Collect tokens from the current stream. */
+			dest.add(tk);
+		}
+
+		return true;
+	}
+
+	/** Create a new stream. */
+	public void newStream() {
+		streams.insertAfter(new FunctionalList<>());
+	}
+
+	/**
+	 * Move to a stream to the right.
+	 *
+	 * @return Whether or not the move was successful.
+	 */
+	public boolean rightStream() {
+		if(!streams.right()) {
+			Errors.inst.printError(EK_STRM_NONEX);
+			return false;
+		}
+
+		currStream = streams.item();
+		return true;
+	}
+
+	/**
+	 * Move to a stream to the left.
+	 *
+	 * @return Whether or not the move was successful.
+	 */
+	public boolean leftStream() {
+		if(!streams.left()) {
+			Errors.inst.printError(EK_STRM_NONEX);
+			return false;
+		}
+
+		currStream = streams.item();
+		return true;
+	}
+
+	/**
+	 * Delete the current stream.
+	 *
+	 * @return Whether or not the delete succeeded.
+	 */
+	public boolean deleteStream() {
+		if(streams.size() == 1) {
+			Errors.inst.printError(EK_STRM_LAST);
+			return false;
+		}
+
+		streams.remove();
+		currStream = streams.item();
+
+		return true;
+	}
+
+	/**
+	 * Merge the current stream into the previous stream.
+	 *
+	 * @return Whether or not the merge succeded.
+	 */
+	public boolean mergeStream() {
+		if(streams.size() == 1) {
+			Errors.inst.printError(EK_STRM_LAST);
+			return false;
+		}
+
+		final IList<String> stringLit = streams.remove();
+		currStream = streams.item();
+		currStream.add(ListUtils.collapseTokens(stringLit, " "));
+
+		return true;
+	}
+
+	private boolean processCommand(final String tk) {
+		char[] comms = null;
+
+		if(tk.length() > 5) {
+			/* Pull off {@S and closing } */
+			comms = tk.substring(3, tk.length() - 1).toCharArray();
+		} else {
+			/* Its a single char. command. */
+			comms = new char[1];
+			comms[0] = tk.charAt(3);
+		}
+
+		/* Process each command. */
+		for(final char comm : comms) {
+			boolean succ = commands.getOrDefault(comm, (eng) -> {
+				Errors.inst.printError(EK_STRM_INVCOM, tk);
+				return false;
+			}).test(this);
+
+			if(!succ) return false;
+		}
+
+		return true;
+	}
+}
+\ No newline at end of file