--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/goodjava/json/JsonParser.java	Tue Sep 17 01:35:01 2019 -0400
@@ -0,0 +1,216 @@
+package goodjava.json;
+
+import java.util.List;
+import java.util.ArrayList;
+import java.util.Map;
+import java.util.LinkedHashMap;
+import java.util.Collections;
+import goodjava.parser.Parser;
+import goodjava.parser.ParseException;
+
+
+public final class JsonParser {
+
+	public static Object parse(String text) throws ParseException {
+		return new JsonParser(text).parse();
+	}
+
+	private final Parser parser;
+
+	private JsonParser(String text) {
+		this.parser = new Parser(text);
+	}
+
+	private ParseException exception(String msg) {
+		return new ParseException(parser,msg);
+	}
+
+	private Object parse() throws ParseException {
+		spaces();
+		Object value = value();
+		spaces();
+		if( !parser.endOfInput() )
+			throw exception("unexpected text");
+		return value;
+	}
+
+	private Object value() throws ParseException {
+		if( parser.match("null") )
+			return null;
+		if( parser.match("true") )
+			return Boolean.TRUE;
+		if( parser.match("false") )
+			return Boolean.FALSE;
+		String s = string();
+		if( s != null )
+			return s;
+		Number n = number();
+		if( n != null )
+			return n;
+		List a = array();
+		if( a != null )
+			return a;
+		Map o = object();
+		if( o != null )
+			return o;
+		throw exception("invalid value");
+	}
+
+	private String string() throws ParseException {
+		parser.begin();
+		if( !parser.match('"') )
+			return parser.failure(null);
+		StringBuilder sb = new StringBuilder();
+		while( parser.anyChar() ) {
+			char c = parser.lastChar();
+			switch(c) {
+			case '"':
+				return parser.success(sb.toString());
+			case '\\':
+				if( parser.anyChar() ) {
+					c = parser.lastChar();
+					switch(c) {
+					case '"':
+					case '\'':  // not in spec
+					case '\\':
+					case '/':
+						sb.append(c);
+						continue;
+					case 'b':
+						sb.append('\b');
+						continue;
+					case 'f':
+						sb.append('\f');
+						continue;
+					case 'n':
+						sb.append('\n');
+						continue;
+					case 'r':
+						sb.append('\r');
+						continue;
+					case 't':
+						sb.append('\t');
+						continue;
+					case 'u':
+						int n = 0;
+						for( int i=0; i<4; i++ ) {
+							int d;
+							if( parser.inCharRange('0','9') ) {
+								d = parser.lastChar() - '0';
+							} else if( parser.inCharRange('a','f') ) {
+								d = parser.lastChar() - 'a' + 10;
+							} else if( parser.inCharRange('A','F') ) {
+								d = parser.lastChar() - 'A' + 10;
+							} else {
+								throw exception("invalid hex digit");
+							}
+							n = 16*n + d;
+						}
+						sb.append((char)n);
+						continue;
+					}
+				}
+				throw exception("invalid escape char");
+			default:
+				sb.append(c);
+			}
+		}
+		parser.failure();
+		throw exception("unclosed string");
+	}
+
+	private Number number() {
+		int start = parser.begin();
+		boolean isFloat = false;
+		parser.match('-');
+		if( !parser.match('0') ) {
+			if( !parser.inCharRange('1','9') )
+				return parser.failure(null);
+			while( parser.inCharRange('0','9') );
+		}
+		if( parser.match('.') ) {
+			if( !parser.inCharRange('0','9') )
+				return parser.failure(null);
+			while( parser.inCharRange('0','9') );
+			isFloat = true;
+		}
+		if( parser.anyOf("eE") ) {
+			parser.anyOf("+-");
+			if( !parser.inCharRange('0','9') )
+				return parser.failure(null);
+			while( parser.inCharRange('0','9') );
+			isFloat = true;
+		}
+		String s = parser.textFrom(start);
+		Number n;
+		if(isFloat)
+			n = Double.valueOf(s);
+		else
+			n = Long.valueOf(s);
+		return parser.success(n);
+	}
+
+	private List array() throws ParseException {
+		parser.begin();
+		if( !parser.match('[') )
+			return parser.failure(null);
+		spaces();
+		if( parser.match(']') )
+			return parser.success(Collections.emptyList());
+		List list = new ArrayList();
+		list.add( value() );
+		spaces();
+		while( parser.match(',') ) {
+			spaces();
+			list.add( value() );
+			spaces();
+		}
+		if( parser.match(']') )
+			return parser.success(list);
+		if( parser.endOfInput() ) {
+			parser.failure();
+			throw exception("unclosed array");
+		}
+		throw exception("unexpected text in array");
+	}
+
+	private Map object() throws ParseException {
+		parser.begin();
+		if( !parser.match('{') )
+			return parser.failure(null);
+		spaces();
+		if( parser.match('}') )
+			return parser.success(Collections.emptyMap());
+		Map map = new LinkedHashMap();
+		addEntry(map);
+		while( parser.match(',') ) {
+			spaces();
+			addEntry(map);
+		}
+		if( parser.match('}') )
+			return parser.success(map);
+		if( parser.endOfInput() ) {
+			parser.failure();
+			throw exception("unclosed object");
+		}
+		throw exception("unexpected text in object");
+	}
+
+	private void addEntry(Map map) throws ParseException {
+		String key = string();
+		if( key==null )
+			throw exception("invalid object key");
+		spaces();
+		if( !parser.match(':') )
+			throw exception("':' expected");
+		spaces();
+		Object value = value();
+		spaces();
+		map.put(key,value);
+	}
+
+	private void spaces() {
+		while( parser.anyOf(" \t\r\n") );
+	}
+
+}