/**
* Creates a DecimalValue from a given string.
*
* The decimal notation for the value is based on ISO 31-0, with some modifications:
* - the decimal separator is '.' (period). Comma is not used anywhere.
* - leading and trailing as well as any internal whitespace is ignored
* - the following characters are ignored: comma (","), apostrophe ("'").
* - scientific (exponential) notation is supported using the pattern /e[-+]\d+/
* - the number may start (or end) with a decimal point.
* - leading zeroes are stripped, except directly before the decimal point
* - trailing zeroes are stripped, except directly after the decimal point
* - zero is always positive.
*
* @see StringValueParser::stringParse
*
* @since 0.1
*
* @param string $value
*
* @return DecimalValue
* @throws ParseException
*/
protected function stringParse($value)
{
$rawValue = $value;
$value = $this->unlocalizer->unlocalizeNumber($value);
//handle scientific notation
list($value, $exponent) = $this->splitDecimalExponent($value);
$value = $this->normalizeDecimal($value);
if ($value === '') {
throw new ParseException('Decimal value must not be empty', $rawValue, self::FORMAT_NAME);
}
try {
$decimal = new DecimalValue($value);
$decimal = $this->applyDecimalExponent($decimal, $exponent);
return $decimal;
} catch (IllegalValueException $ex) {
throw new ParseException($ex->getMessage(), $rawValue, self::FORMAT_NAME);
}
}
/**
* Splits a quantity string into its syntactic parts.
*
* @see newQuantityFromParts
*
* @param string $value
*
* @throws InvalidArgumentException If $value is not a string
* @throws ParseException If $value does not match the expected pattern
* @return array list( $amount, $exactness, $margin, $unit ).
* Parts not present in $value will be null
*/
private function splitQuantityString($value)
{
if (!is_string($value)) {
throw new InvalidArgumentException('$value must be a string');
}
//TODO: allow explicitly specifying the number of significant figures
//TODO: allow explicitly specifying the uncertainty interval
$numberPattern = $this->unlocalizer->getNumberRegex('@');
$unitPattern = $this->unlocalizer->getUnitRegex('@');
$pattern = '@^' . '\\s*(' . $numberPattern . ')' . '\\s*(?:' . '([~!])' . '|(?:\\+/?-|±)\\s*(' . $numberPattern . ')' . '|' . ')' . '\\s*(' . $unitPattern . ')?' . '\\s*$@u';
if (!preg_match($pattern, $value, $groups)) {
throw new ParseException('Malformed quantity', $value, self::FORMAT_NAME);
}
// Remove $0.
array_shift($groups);
array_walk($groups, function (&$element) {
if ($element === '') {
$element = null;
}
});
return array_pad($groups, 4, null);
}
/**
* Splits a quantity string into its syntactic parts.
*
* @see newQuantityFromParts
*
* @param string $value
*
* @throws InvalidArgumentException If $value is not a string
* @throws ParseException If $value does not match the expected pattern
* @return array list( $amount, $exactness, $margin, $unit ).
* Parts not present in $value will be null
*/
private function splitQuantityString($value)
{
if (!is_string($value)) {
throw new InvalidArgumentException('$value must be a string');
}
//TODO: allow explicitly specifying the number of significant figures
//TODO: allow explicitly specifying the uncertainty interval
$numberPattern = $this->unlocalizer->getNumberRegex('@');
$unitPattern = $this->unlocalizer->getUnitRegex('@');
$pattern = '@^' . '\\s*(' . $numberPattern . ')' . '\\s*(?:' . '([~!])' . '|(?:\\+/?-|±)\\s*(' . $numberPattern . ')' . '|' . ')' . '\\s*(' . $unitPattern . ')?' . '\\s*$@u';
if (!preg_match($pattern, $value, $groups)) {
throw new ParseException('Malformed quantity', $value, self::FORMAT_NAME);
}
for ($i = 1; $i <= 4; $i++) {
if (!isset($groups[$i])) {
$groups[$i] = null;
} elseif ($groups[$i] === '') {
$groups[$i] = null;
}
}
array_shift($groups);
// remove $groups[0]
return $groups;
}
