/**
* Parse a value.
*
* @param tb Source.
* @param type The type of the array, may be any..
* @param valueList Result added here.
* @return Return true if a value has been added to the valueList and the cursor advanced or false
* and the cursor is as it was.
*/
private static boolean value(Text t, DataType type, List<Object> valueList) {
boolean result;
if (t.isEof()) {
result = false;
} else if (t.consume("null")) {
valueList.add(null);
result = true;
} else {
switch (type) {
case z:
case Z:
case f:
case F:
result = number(t, type, valueList);
break;
case text:
result = text(t, valueList);
break;
case identifier:
result = identifier(t, valueList);
break;
case path:
result = path(t, valueList);
break;
case datetime:
result = datetime(t, valueList);
break;
case date:
result = date(t, valueList);
break;
case time:
result = time(t, valueList);
break;
case bool:
result = bool(t, valueList);
break;
case cardinality:
result = cardinality(t, valueList);
break;
case any:
result = any(t, valueList);
break;
default:
throw new UnexpectedException("value: " + type);
}
}
return result;
}
/**
* Parse a string value and covert it to its proper data type.
*
* @param value
* @return The parsed value.
* @throws ParsingException Thrown if not Advisory is available and there was an error parsing.
*/
@SuppressWarnings("unchecked")
public static <T> T parseValue(String value) throws ParsingException {
final T result;
assert value != null;
/*
* todo Restructure the whole class so I've got parse and parseArray as
* static methods and the share code properly.
*/
if ("null".equals(value)) {
result = null;
} else {
final List<Object> list = new ArrayList<>();
final Text t = new Text();
t.append(value);
if (any(t, list) && t.isEof()) {
result = (T) list.get(0);
} else {
error("Count not parse value: " + value);
result = null;
}
}
return result;
}
private static boolean number(Text t, DataType requiredType, List<Object> valueList) {
// posNumber
// : cardinality
// | '0b' BinaryDigits+ [zZ]?
// | '0x' HexDigit+ [zZ]?
// | '-'? Pint? ( '.' Digit+ ) ('e' Pint) [fF]
// | '-'? Pint [zZfF]?
// ;
final boolean result;
assert !t.isEof() : "Should have been checked by caller";
if (binary(t, valueList, requiredType) || hex(t, valueList, requiredType)) {
// ?todo I could allow negatives here
// ( binary | hex | '0' )
result = true;
} else {
// ( Int DecPart | Int | DecPart ) ( 'e' Int )? [zZfF]?
final int start = t.cursor();
if ((t.consumeInt() && (decPart(t) || true) && (exponent(t) || true))
|| (t.consume('-') || true) && decPart(t) && (exponent(t) || true)) {
final String string = t.getString(start);
final Object value = deriveType(string, requiredType, t, 10);
valueList.add(value);
result = true;
} else {
result = false;
}
}
return result;
}
/**
* Given the parsing context and what numerical data type is expected convert a string to the
* correct type. Note no attempt is made to let the magnitude of the number influence our choice.
*
* @param string The string to convert to a number. E.g. "123.3e2". If it contains a '.' or an 'e'
* then the type must either be f or F.
* @param requiredType Either z, Z, f, F or any.
* @param tb The source. The cursor will be at the end of the number but any type specifier will
* not have been consumed. If there is one then we'll eat it.
* @return The derived type.
* @throws ParsingException If there is a clash of types.
*/
private static Object deriveType(String string, DataType requiredType, Text t, int radix) {
final Object result;
// Figure out the correct type...
final DataType derivedType;
if (t.isEof()) {
if (requiredType == DataType.any) {
if (string.indexOf('.') >= 0 || string.indexOf('e') >= 0) {
derivedType = DataType.f;
} else {
derivedType = DataType.z;
}
} else {
derivedType = requiredType;
}
} else {
final char c = t.peek();
if (c == 'z' || c == 'Z' || c == 'f' || c == 'F') {
t.consume(c);
derivedType = DataType.valueOf(String.valueOf(c));
if (!(requiredType == DataType.any || requiredType == derivedType)) {
throw new ParsingException("Incompatible type: " + string + c);
}
} else {
if (requiredType == DataType.any) {
if (string.indexOf('.') >= 0 || string.indexOf('e') >= 0) {
derivedType = DataType.f;
} else {
derivedType = DataType.z;
}
} else {
derivedType = requiredType;
}
}
}
switch (derivedType) {
case z:
result = new Long(Long.parseLong(string, radix));
break;
case Z:
result = new BigInteger(string, radix);
break;
case f:
result = new Double(string);
break;
case F:
result = new BigDecimal(string);
break;
// $CASES-OMITTED$
default:
throw new UnexpectedException("toType: " + derivedType);
}
return result;
}
/**
* Parse a string into a list of data values. White space is supported only in between the [square
* brackets].
*
* @param string A string representation of an Oak property array, e.g. [ true, null, false ]
* @param type The type of the array, may be 'any'.
* @return A potentially empty but not null list of values.
*/
@SuppressWarnings("unchecked")
public static <T> List<T> parseArray(String string, DataType type) {
final List<?> result;
final Text t = new Text();
t.append(string);
if (t.consume('[')
&& (result = elementList(t, type)) != null
&& (t.ws() && t.consume(']'))
&& t.isEof()) {
// OK
} else {
throw new ParsingException("Invalid array: " + string);
}
return (List<T>) result;
}
