[comment-loader-extension] Introduce comment loader extension

tweed5-serde-api/src/main/java/de/siphalor/tweed5/dataapi/api/IntuitiveVisitingTweedDataReader.java

@@ -0,0 +1,77 @@
+package de.siphalor.tweed5.dataapi.api;
+
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+public class IntuitiveVisitingTweedDataReader {
+	private final TweedDataVisitor visitor;
+
+	public void readValue(TweedDataReader reader) throws TweedDataReadException {
+		TweedDataToken token = reader.peekToken();
+		if (token.isNull()) {
+			reader.readToken();
+			visitor.visitNull();
+		} else if (token.isListStart()) {
+			readList(reader);
+		} else if (token.isMapStart()) {
+			readMap(reader);
+		} else if (token.canReadAsByte()) {
+			visitor.visitByte(reader.readToken().readAsByte());
+		} else if (token.canReadAsShort()) {
+			visitor.visitShort(reader.readToken().readAsShort());
+		} else if (token.canReadAsInt()) {
+			visitor.visitInt(reader.readToken().readAsInt());
+		} else if (token.canReadAsLong()) {
+			visitor.visitLong(reader.readToken().readAsLong());
+		} else if (token.canReadAsFloat()) {
+			visitor.visitFloat(reader.readToken().readAsFloat());
+		} else if (token.canReadAsDouble()) {
+			visitor.visitDouble(reader.readToken().readAsDouble());
+		} else if (token.canReadAsBoolean()) {
+			visitor.visitBoolean(reader.readToken().readAsBoolean());
+		} else if (token.canReadAsString()) {
+			visitor.visitString(reader.readToken().readAsString());
+		}
+	}
+
+	public void readList(TweedDataReader reader) throws TweedDataReadException {
+		TweedDataToken token = reader.readToken();
+		if (!token.isListStart()) {
+			throw TweedDataReadException.builder().message("Expected list but got " + token).build();
+		}
+
+		visitor.visitListStart();
+		while (true) {
+			token = reader.peekToken();
+			if (token.isListEnd()) {
+				visitor.visitListEnd();
+				reader.readToken();
+				break;
+			} else {
+				readValue(reader);
+			}
+		}
+	}
+
+	public void readMap(TweedDataReader reader) throws TweedDataReadException {
+		TweedDataToken token = reader.readToken();
+		if (!token.isMapStart()) {
+			throw TweedDataReadException.builder().message("Expected map but got " + token).build();
+		}
+
+		visitor.visitMapStart();
+		while (true) {
+			token = reader.peekToken();
+			if (token.isMapEnd()) {
+				reader.readToken();
+				visitor.visitMapEnd();
+				break;
+			} else if (token.isMapEntryKey()) {
+				visitor.visitMapEntryKey(reader.readToken().readAsString());
+				readValue(reader);
+			} else {
+				throw TweedDataReadException.builder().message("Expected map end or entry key but got " + token).build();
+			}
+		}
+	}
+}