/// <summary>
/// Constructs an instance of a FormatManager using the given
/// format string.
/// </summary>
/// <param name="formatString">A FORTRAN format string.</param>
public FormatManager(string formatString)
{
if (formatString == "*") {
formatString = string.Empty;
}
_formatString = formatString;
_fmtLength = _formatString.Length;
_plusRequired = FormatOptionalPlus.Default;
_groups = new Stack();
}
/// <summary>
/// Returns the next FormatRecord from the string or null if
/// there are no further records to retrieve.
/// </summary>
/// <returns>A FormatRecord, or null if we reached the end</returns>
public FormatRecord Next()
{
// Repeat the last record if we've still some
// more to go.
if (_cRepeat > 1) {
--_cRepeat;
return _lastRecord;
}
// Otherwise find the next record and return that.
StringBuilder str = new StringBuilder();
bool inQuote = false;
while (_charIndex < _fmtLength) {
char ch = NextChar();
if (ch == '"' || ch == '\'') {
inQuote = !inQuote;
++_charIndex;
} else if (inQuote) {
str.Append(ch);
++_charIndex;
} else {
if (ch == ',' || Char.IsWhiteSpace(ch)) {
++_charIndex;
continue;
}
// If we've gathered some raw string up to here
// then return that now.
if (str.Length > 0) {
_lastRecord = new FormatRecord();
_lastRecord.RawString = str.ToString();
return _lastRecord;
}
// Remember this offset for _lastFormatGroup later
int markedIndex = _charIndex-1;
// Check and validate any repeat specifier. Note that X, P and H are required to have
// a value preceding them. It's just not treated as repeat.
bool hasPrefixValue = Char.IsDigit(ch) || ch == '-' || ch == '+';
int prefixValue = ExtractNumber(1);
do {
ch = NextChar();
++_charIndex;
} while (Char.IsWhiteSpace(ch));
char formatChar = ch;
// Valid format character?
if ("IFEGLA:/()TXPSHDB".IndexOf(formatChar) < 0) {
throw new JComRuntimeException(string.Format("Unknown format specifier character '{0}'", formatChar));
}
// End record?
if (formatChar == ':') {
return null;
}
// Record separator?
if (formatChar == '/') {
_scaleFactor = 0;
_lastRecord = new FormatRecord();
_lastRecord.IsEndRecord = true;
return _lastRecord;
}
// Group start
if (formatChar == '(') {
if (prefixValue < 0) {
throw new JComRuntimeException("Repeat count cannot be less than 0");
}
FormatGroup formatGroup = new FormatGroup();
formatGroup.GroupRepeat = prefixValue;
formatGroup.GroupStartIndex = _charIndex;
_groups.Push(formatGroup);
// Also remember this format group start in the
// case of a rescan.
if (_groups.Count == 1) {
_lastFormatGroup = markedIndex;
}
continue;
}
// Group end
if (formatChar == ')') {
FormatGroup formatGroup = (FormatGroup)_groups.Pop();
if (formatGroup == null) {
throw new JComRuntimeException("Parenthesis mismatch in FORMAT statement");
}
if (--formatGroup.GroupRepeat > 0) {
_charIndex = formatGroup.GroupStartIndex;
_groups.Push(formatGroup);
}
continue;
}
// Make sure a prefix value is specified for those format characters
// that require one, and not specified for those that don't.
if (formatChar == 'X' || formatChar == 'P'|| formatChar == 'H') {
if (!hasPrefixValue) {
throw new JComRuntimeException(String.Format("'{0}' specifier requires a value", formatChar));
}
} else {
if (hasPrefixValue && "IFEDGLA".IndexOf(formatChar) < 0) {
throw new JComRuntimeException(String.Format("Repeat count not permitted with '{0}' specifier", formatChar));
}
if (prefixValue < 0) {
throw new JComRuntimeException("Repeat count cannot be less than 0");
}
_cRepeat = prefixValue;
}
// Handle cursor positioning. The following formats are recognised:
// T<n> - set the cursor position to offset <n> in the current record.
// TL<n> - move the cursor back <n> characters
// TR<n> - move the cursor forward <n> characters
if (formatChar == 'T') {
_lastRecord = new FormatRecord();
_lastRecord.FormatChar = 'T';
switch (NextChar()) {
case 'L':
++_charIndex;
_lastRecord.Relative = true;
_lastRecord.Count = -ExtractNumber(0);
return _lastRecord;
case 'R':
++_charIndex;
_lastRecord.Relative = true;
_lastRecord.Count = ExtractNumber(0);
return _lastRecord;
default:
_lastRecord.Count = ExtractNumber(0);
return _lastRecord;
}
}
// Handle forward cursor movement. This is pretty much the
// same as TR<n>.
if (formatChar == 'X') {
_lastRecord = new FormatRecord();
_lastRecord.FormatChar = 'T';
_lastRecord.Relative = true;
_lastRecord.Count = prefixValue;
_cRepeat = 1;
return _lastRecord;
}
// Handle scale factor. This influences subsequent
// formats on the same record.
if (formatChar == 'P') {
_scaleFactor = prefixValue;
_cRepeat = 1;
continue;
}
// Handle blank specifier which controls whether blank
// characters are ignored or treated as '0'.
if (formatChar == 'B') {
_blanksAsZero = NextChar() == 'Z';
++_charIndex;
continue;
}
// Handle positive sign specification.
if (formatChar == 'S') {
switch (NextChar()) {
case 'P':
++_charIndex;
_plusRequired = FormatOptionalPlus.Always;
break;
case 'S':
++_charIndex;
_plusRequired = FormatOptionalPlus.Never;
break;
default:
_plusRequired = FormatOptionalPlus.Default;
break;
}
continue;
}
// Hollerith character output
// The prefix value is the count of subsequent characters in the format
// string that are copied literally to the output.
if (formatChar == 'H') {
while (prefixValue > 0 && _charIndex < _fmtLength) {
str.Append(NextChar());
--prefixValue;
++_charIndex;
}
continue;
}
// If we get here then we're left with formatting characters that accept a
// width and precision specifier. So parse those off.
int precision = 1;
int exponentWidth = 0;
int fieldWidth = ExtractNumber(0);
if (NextChar() == '.') {
++_charIndex;
precision = ExtractNumber(0);
if ((formatChar == 'E' || formatChar == 'G') && NextChar() == 'E') {
++_charIndex;
exponentWidth = ExtractNumber(2);
}
}
// We've got a full format specifier so return
// that back to the caller.
_lastRecord = new FormatRecord();
_lastRecord.FormatChar = formatChar;
_lastRecord.FieldWidth = fieldWidth;
_lastRecord.Precision = precision;
_lastRecord.Count = _cRepeat;
_lastRecord.ExponentWidth = exponentWidth;
_lastRecord.PlusRequired = _plusRequired;
_lastRecord.ScaleFactor = _scaleFactor;
_lastRecord.BlanksAsZero = _blanksAsZero;
return _lastRecord;
}
}
if (str.Length > 0) {
_lastRecord = new FormatRecord();
_lastRecord.RawString = str.ToString();
return _lastRecord;
}
if (_groups.Count > 0) {
throw new JComRuntimeException("Unclosed format specifier group");
}
return null;
}
