private Type1Token ReadNextToken()
{
previousToken = CurrentToken;
bool skip;
do
{
skip = false;
while (bytes.MoveNext())
{
var b = bytes.CurrentByte;
var c = (char)b;
switch (c)
{
case '%':
comments.Add(ReadComment());
break;
case '(':
return(ReadString());
case ')':
throw new InvalidOperationException("Encountered an end of string ')' outside of string.");
case '[':
return(new Type1Token(c, Type1Token.TokenType.StartArray));
case ']':
return(new Type1Token(c, Type1Token.TokenType.EndArray));
case '{':
return(new Type1Token(c, Type1Token.TokenType.StartProc));
case '}':
return(new Type1Token(c, Type1Token.TokenType.EndProc));
case '/':
{
var name = ReadLiteral();
return(new Type1Token(name, Type1Token.TokenType.Literal));
}
case '<':
{
var following = bytes.Peek();
if (following == '<')
{
bytes.MoveNext();
return(new Type1Token("<<", Type1Token.TokenType.StartDict));
}
return(new Type1Token(c, Type1Token.TokenType.Name));
}
case '>':
{
var following = bytes.Peek();
if (following == '>')
{
bytes.MoveNext();
return(new Type1Token(">>", Type1Token.TokenType.EndDict));
}
return(new Type1Token(c, Type1Token.TokenType.Name));
}
default:
{
if (ReadHelper.IsWhitespace(b))
{
skip = true;
break;
}
if (b == 0)
{
skip = true;
break;
}
if (TryReadNumber(c, out var number))
{
return(number);
}
var name = ReadLiteral(c);
if (name == null)
{
throw new InvalidOperationException($"The binary portion of the type 1 font was invalid at position {bytes.CurrentOffset}.");
}
if (name.Equals(Type1Symbols.RdProcedure, StringComparison.OrdinalIgnoreCase) || name.Equals(Type1Symbols.RdProcedureAlt))
{
if (previousToken.Type == Type1Token.TokenType.Integer)
{
return(ReadCharString(previousToken.AsInt()));
}
throw new InvalidOperationException($"Expected integer token before {name} at offset {bytes.CurrentOffset}.");
}
return(new Type1Token(name, Type1Token.TokenType.Name));
}
}
}
} while (skip);
return(null);
}
public Type1Tokenizer(IInputBytes bytes)
{
this.bytes = bytes;
comments = new List <string>();
CurrentToken = ReadNextToken();
}
public Type1Token GetNext()
{
CurrentToken = ReadNextToken();
return(CurrentToken);
}
private bool TryReadNumber(char c, out Type1Token numberToken)
{
char GetNext()
{
bytes.MoveNext();
return((char)bytes.CurrentByte);
}
numberToken = null;
var currentPosition = bytes.CurrentOffset;
var sb = new StringBuilder();
StringBuilder radix = null;
var hasDigit = false;
// optional + or -
if (c == '+' || c == '-')
{
sb.Append(c);
c = GetNext();
}
// optional digits
while (char.IsDigit(c))
{
sb.Append(c);
c = GetNext();
hasDigit = true;
}
// optional .
if (c == '.')
{
sb.Append(c);
c = GetNext();
}
else if (c == '#')
{
// PostScript radix number takes the form base#number
radix = sb;
sb = new StringBuilder();
c = GetNext();
}
else if (sb.Length == 0 || !hasDigit)
{
// failure
bytes.Seek(currentPosition);
return(false);
}
else
{
// integer
bytes.Seek(bytes.CurrentOffset - 1);
numberToken = new Type1Token(sb.ToString(), Type1Token.TokenType.Integer);
return(true);
}
// required digit
if (char.IsDigit(c))
{
sb.Append(c);
c = GetNext();
}
else
{
bytes.Seek(currentPosition);
return(false);
}
// optional digits
while (char.IsDigit(c))
{
sb.Append(c);
c = GetNext();
}
// optional E
if (c == 'E')
{
sb.Append(c);
c = GetNext();
// optional minus
if (c == '-')
{
sb.Append(c);
c = GetNext();
}
// required digit
if (char.IsDigit(c))
{
sb.Append(c);
c = GetNext();
}
else
{
bytes.Seek(currentPosition);
return(false);
}
// optional digits
while (char.IsDigit(c))
{
sb.Append(c);
c = GetNext();
}
}
bytes.Seek(bytes.CurrentOffset - 1);
if (radix != null)
{
var number = Convert.ToInt32(sb.ToString(), int.Parse(radix.ToString(), CultureInfo.InvariantCulture));
numberToken = new Type1Token(number.ToString(), Type1Token.TokenType.Integer);
}
else
{
numberToken = new Type1Token(sb.ToString(), Type1Token.TokenType.Real);
}
return(true);
}
