1 files changed, 102 insertions, 0 deletions
diff --git a/base/src/main/java/bjc/utils/ioutils/blocks/MLPromptBlockReader.java b/base/src/main/java/bjc/utils/ioutils/blocks/MLPromptBlockReader.java
new file mode 100644
index 0000000..981c5aa
--- /dev/null
+++ b/base/src/main/java/bjc/utils/ioutils/blocks/MLPromptBlockReader.java
@@ -0,0 +1,102 @@
+package bjc.utils.ioutils.blocks;
+
+import java.io.*;
+import java.util.Scanner;
+
+/**
+ * A block reader that uses bash-style multi-line prompts to read blocks.
+ * 
+ * The format of the blocks returned by this is indented blocks <code> x y z a b
+ * 
+ * c -- block split here d <code>
+ * 
+ * @author bjcul
+ *
+ */
+public class MLPromptBlockReader implements BlockReader {
+	private String firstPrompt;
+	private String secondPrompt;
+
+	private Scanner input;
+	private Writer output;
+
+	private Block currBlock;
+	
+	/* Info about the current block. */
+	private int blockNo = 0;
+	private int lineNo  = 1;
+	
+	private String nextInitLine;
+	/**
+	 * Create a new multi-line prompt block reader.
+	 * 
+	 * @param firstPrompt  The initial prompt. Is treated as a format string, with
+	 *                     %1 being the block number and %2 being the line number
+	 * @param secondPrompt The secondary prompt. Is also treated as a format string
+	 *                     with %1 and %2 as firstPrompt, and %3 as the continuation line
+	 *                     number
+	 * 
+	 * @param input        The input source
+	 * @param output       The output destination
+	 */
+	public MLPromptBlockReader(String firstPrompt, String secondPrompt, Reader input, Writer output) {
+		this.firstPrompt = firstPrompt;
+		this.secondPrompt = secondPrompt;
+		this.input = new Scanner(input);
+		this.output = output;
+	}
+
+	@Override
+	public boolean hasNextBlock() {
+		return input.hasNextLine();
+	}
+
+	@Override
+	public Block getBlock() {
+		return currBlock;
+	}
+
+	@Override
+	public boolean nextBlock() {
+		StringBuilder blockContents = new StringBuilder();
+		
+		String currLn;
+		if (nextInitLine == null) {
+			try {
+				output.write(String.format(firstPrompt, blockNo, lineNo));
+			} catch (IOException ioex) {
+				throw new RuntimeException(ioex);
+			}
+			currLn = input.nextLine();
+		} else {
+			currLn = nextInitLine;
+		}
+		
+		blockContents.append(currLn);
+		
+		int startLn = lineNo;
+		int endLn = lineNo++;
+		
+		boolean inBlock = true;
+		while(input.hasNextLine() && inBlock) {
+			currLn = input.nextLine();
+			
+			int initCh = currLn.codePointAt(0);
+			inBlock = Character.isSpaceChar(initCh);
+		}
+		
+		currBlock = new Block(blockNo++, blockContents.toString(), startLn, endLn);
+		return true;
+	}
+
+	@Override
+	public int getBlockCount() {
+		return blockNo;
+	}
+
+	@Override
+	public void close() throws IOException {
+		input.close();
+	}
+
+}