string TransitionFunction(char c)
{
string ret = STATE_INIT;
if (mode_stream)
{
AccumulateStream(c);
}
PdfStateTransition transition = FindTransition(c);
if (transition != null)
{
if (transition.back == 0)
{
Accumulate(c);
this.current_token.type = transition.state_out;
}
this.current_state = transition.state_out;
this.read_offset -= transition.back;
if (transition.acceptance)
{
if (this.current_token.lexeme == "stream")
{
mode_stream = true;
stream_token = new PdfToken();
stream_token.type = "STREAM";
}
if (this.current_token.lexeme == "endstream")
{
mode_stream = false;
this.tokens.Add(this.stream_token);
}
this.tokens.Add(this.current_token);
this.current_token = new PdfToken();
this.current_state = STATE_INIT;
}
}
return(ret);
}
void AddStateTransition(
string state_in,
string pattern,
string state_out,
bool acceptance = false,
int back = 0
)
{
PdfStateTransition transition = new PdfStateTransition()
{
state_in = state_in,
pattern = pattern,
state_out = state_out,
acceptance = acceptance,
back = back
};
this.transition_table.Add(transition);
}
PdfStateTransition FindTransition(char c)
{
PdfStateTransition ret = null;
bool found = false;
int current = 0;
while (transition_table.Count > current && !found)
{
if (transition_table[current].state_in == this.current_state)
{
if (Regex.IsMatch(c.ToString(), transition_table[current].pattern))
{
ret = transition_table[current];
found = true;
}
}
current++;
}
return(ret);
}
