Basic stream commands

1 files changed, 73 insertions, 0 deletions

diff --git a/dice-lang/src/bjc/dicelang/v2/StreamEngine.java b/dice-lang/src/bjc/dicelang/v2/StreamEngine.java
new file mode 100644
index 0000000..c17abe4
--- /dev/null
+++ b/dice-lang/src/bjc/dicelang/v2/StreamEngine.java
@@ -0,0 +1,73 @@
+package bjc.dicelang.v2;
+
+import bjc.utils.funcdata.FunctionalList;
+import bjc.utils.funcdata.IList;
+import bjc.utils.esodata.Tape;
+
+public class StreamEngine {
+	private DiceLangEngine eng;
+
+	private Tape<IList<String>> streams;
+	private IList<String>       currStream;
+
+	public StreamEngine(DiceLangEngine eng) {
+		streams = new Tape<>();
+
+		currStream = new FunctionalList<>();
+		streams.append(currStream);
+	}
+
+	public boolean doStreams(String[] toks, IList<String> dest) {
+		for(String tk : toks) {
+			if(tk.startsWith("{@")) {
+				if(!processCommand(tk)) return false;
+			} else {
+				currStream.add(tk);
+			}
+		}
+
+		for(String tk : currStream.toIterable()) {
+			dest.add(tk);
+		}
+
+		return true;
+	}
+
+	private boolean processCommand(String tk) {
+		switch(tk.charAt(2)) {
+			case '+':
+				streams.append(new FunctionalList<>());
+				break;
+			case '>':
+				if(!streams.right()) {
+					System.out.println("\tERROR: Attempted to switch to non-existent stream");
+					return false;
+				}
+
+				currStream = streams.item();
+				break;
+			case '<':
+				if(!streams.left()) {
+					System.out.println("\tERROR: Attempted to switch to non-existent stream");
+					return false;
+				}
+
+				currStream = streams.item();
+				break;
+			case '-':
+				if(streams.size() == 1) {
+					System.out.println("\tERROR: Cannot delete last stream");
+					return false;
+				} else {
+					streams.remove();
+					currStream = streams.item();
+				}
+				break;
+			default:
+				System.out.println("\tERROR: Unknown stream control command: " + tk);
+				return false;
+		}
+
+		return true;
+	}
+}