Groovy source code from blog post "A very simple data file metaformat" at http://octodecillion.com/blog/very-simple-data-file-format/

Vsdf.groovy

package com.octodecillion.inix

import java.util.regex.Pattern
import groovy.transform.TypeChecked
import java.util.regex.Matcher

/**
 * 
 * 
 * @author Josef Betancourt
 *
 */
class Inix {
	String iniFilePath
	Reader reader
	int lineNum
	int sectionNum
	Event data

	def state = State.INIT

	/**
	 * Value object for parsed sections.
	 *  
	 */
	class Event {
		EventType event
		String subsection
		String id
		String text 
		int lineNum
		int sectionNum
		String sectionString
		
		String toString() {
			return "id=[$id],subsection=[$subsection]"
			
		};
	}

	Event getEvent(){
		return data
	}

	/**
	 * Pull event style processing.
	 * 
	 * @return event structure
	 */
	EventType next(){
		String line = reader.readLine()
		lineNum++

		if(line == null){
			return EventType.END
		}

		if( isBlank(line)){
			skipLines(reader)
		}

		if(line == null){
			return EventType.END
		}
		
		String type =''
		String subsection = ''
		String id = ''
		data = new Event()
		EventType eventType
		
		line = line.trim()

		if(isComment(line)){
			data.text = line
			data.event = EventType.COMMENT
			data.lineNum = lineNum
			eventType = EventType.COMMENT
		}

		if(isSection(line)){ // section?
			eventType = EventType.SECTION
			data.sectionString = line
			sectionNum++
			processSection(line, sectionNum, data)
		} // end if section head

		return eventType
	}

	/**
	 * Get metadata and content of section.
	 * 
	 * @param line
	 * @return
	 */
	def processSection(String line, int sectionNum, Event data){
		data.event = EventType.SECTION
		data.sectionNum = sectionNum

		Matcher m = (line =~ /^\[>(.*)\]/)
		String mString = m[0][1]
		def current = mString.trim()
		if(!current){
			def msg = "section $sectionNum is blank"
			throw new IllegalArgumentException(msg)
		}

		def parts = (current =~ /^(.*)\/(.*)$/)
		if(!parts){
			data.id = current
		}else{
			long size = ((String[])parts[0]).length
			data.id = size > 1  ? parts[0][1] : ''
			data.subsection = size > 2 ? parts[0][2] : ''
		}

		String readData = readSectionData()
		data.text = readData
	}

	/**
	 * Get data in section.
	 * 
	 * @return  data as string
	 */
	String readSectionData(){
		StringBuilder buffer = new StringBuilder(8*1024)

		while(true){
			String line = reader.readLine()
			lineNum++

			if(line == null){
				break
			}
			
			line = line.trim()

			if(isEnd(line)){ 
				break			
			}else if(isSection(line)){
				throw new IllegalArgumentException("Unterminated section")
			}else{
				buffer.append(line + LINESEP)
			}
		}

		return buffer.toString()
	}
	
	def skipLines(reader){
		while(true){
			line = reader.readLine()
			lineNum++
			if(line  || line == null){
				break
			}
		}
	}
	
	def isSection(line){
		return line =~ /^\[>.*\]/
	}

	def isEnd(line){
		return line =~ /^\[<.*\]/ || line =~ /^\[>.*\]/		
	}
	def isBlank(s) {
		return (s == null ? false : (s.trim().length() ==0 ? true : false))		
	}
	
	def isComment(line) {		
		return line =~ /^\s*[#;]/		
	}
	
	private static final String BLANK = ""
	static final String LINESEP = System.getProperty("line.separator")

	enum State {
		INIT, ACCEPT, SHIFT, END
	}

	public enum EventType {
		COMMENT, SECTION, END
	}

} // end of class Inix