public static Template Parse()
{
StackElement st = new StackElement();
st.state = 0;
stack.Push(st);
char lookahead;
int intVal;
invokeLexer(out lookahead, out intVal);
while (stack.Peek().state != 1 || lookahead != '$')
{
processOneStep(lookahead, intVal);
invokeLexer(out lookahead, out intVal);
}
Template ret = stack.Peek().tempVal;
stack.Peek().tempVal = null;
return(ret);
}
public static void processOneStep(char lookahead, int intVal)
{
Debug.Assert(stack.Count() > 0);
StackElement topElement = stack.Peek();
Dictionary<char, int> tableRow;
if(shift.TryGetValue(topElement.state, out tableRow))
{
int tableValue;
if(tableRow.TryGetValue(lookahead, out tableValue))
{
if(lookahead == 'i')
{
StackElement st = new StackElement(intVal);
st.state = tableValue;
stack.Push(st);
// remove the integer at the beginning of the string str
Debug.Assert(str.ElementAt(0) <= '9' && str.ElementAt(0) >= '0');
int pos = str.IndexOfAny("();,".ToCharArray(), 0);
if (pos > -1)
{
str = str.Substring(pos);
}
else
{
str = str.Substring(str.Length);
}
}
else
{
StackElement st = new StackElement(lookahead);
st.state = tableValue;
stack.Push(st);
str = str.Substring(1);
}
return;
}
// else case
Console.WriteLine("Error encountered while parsing the template!");
Console.WriteLine("Shift rule not defined for lookahead char {0} in state {1}", lookahead, topElement.state);
Debug.Assert(false);
}
// reduce operation
if (reduce.TryGetValue(topElement.state, out tableRow))
{
int tableValue;
if (tableRow.TryGetValue(lookahead, out tableValue))
{
switch (tableValue)
{
// which reduce rule do we have to apply?
case 1:
{
StackElement rightBracket = stack.Pop();
Debug.Assert(rightBracket.t == StackElementType.charType);
Debug.Assert(rightBracket.charVal == ')');
StackElement template = stack.Pop();
Debug.Assert(template.t == StackElementType.templateType);
StackElement leftBracket = stack.Pop();
Debug.Assert(leftBracket.t == StackElementType.charType);
Debug.Assert(leftBracket.charVal == '(');
int newState = goto_actions[stack.Peek().state]['t'];
StackElement st = new StackElement(template.tempVal);
st.state = newState;
template.tempVal = null;
stack.Push(st);
break;
}
case 2:
{
StackElement rightTemp = stack.Pop();
Debug.Assert(rightTemp.t == StackElementType.templateType);
StackElement semi_colon = stack.Pop();
Debug.Assert(semi_colon.t == StackElementType.charType);
Debug.Assert(semi_colon.charVal == ';');
StackElement leftTemp = stack.Pop();
Debug.Assert(leftTemp.t == StackElementType.templateType);
StackElement st = new StackElement(new Template(TemplateOperator.DisjunctionOp, leftTemp.tempVal, rightTemp.tempVal));
int newState = goto_actions[stack.Peek().state]['t'];
st.state = newState;
leftTemp.tempVal = null;
rightTemp.tempVal = null;
stack.Push(st);
break;
}
case 3:
{
StackElement rightTemp = stack.Pop();
Debug.Assert(rightTemp.t == StackElementType.templateType);
StackElement comma = stack.Pop();
Debug.Assert(comma.t == StackElementType.charType);
Debug.Assert(comma.charVal == ',');
StackElement leftTemp = stack.Pop();
Debug.Assert(leftTemp.t == StackElementType.templateType);
StackElement st = new StackElement(new Template(TemplateOperator.ConjunctionOp, leftTemp.tempVal, rightTemp.tempVal));
int newState = goto_actions[stack.Peek().state]['t'];
st.state = newState;
leftTemp.tempVal = null;
rightTemp.tempVal = null;
stack.Push(st);
break;
}
case 4:
{
StackElement intElement = stack.Pop();
Debug.Assert(intElement.t == StackElementType.intType);
int newstate = goto_actions[stack.Peek().state]['t'];
StackElement st = new StackElement(new Template(intElement.intVal));
st.state = newstate;
stack.Push(st);
break;
}
default:
Console.WriteLine("Error encountered while parsing the template!");
Console.WriteLine("Unknown reduction rule sought.");
Debug.Assert(false);
break;
}
return;
}
else
{
Console.WriteLine("Error encountered while parsing the template!");
Console.WriteLine("reduce rule not defined for lookahead char {0} in state {1}", lookahead, topElement.state);
Debug.Assert(false);
}
}
else
{
Console.WriteLine("Error encountered while parsing template!");
Console.WriteLine("No entry in ParserTable corresponding to the current state {0} on top of the stack.", topElement.state);
Debug.Assert(false);
}
return;
}
public static void processOneStep(char lookahead, int intVal)
{
Debug.Assert(stack.Count() > 0);
StackElement topElement = stack.Peek();
Dictionary <char, int> tableRow;
if (shift.TryGetValue(topElement.state, out tableRow))
{
int tableValue;
if (tableRow.TryGetValue(lookahead, out tableValue))
{
if (lookahead == 'i')
{
StackElement st = new StackElement(intVal);
st.state = tableValue;
stack.Push(st);
// remove the integer at the beginning of the string str
Debug.Assert(str.ElementAt(0) <= '9' && str.ElementAt(0) >= '0');
int pos = str.IndexOfAny("();,".ToCharArray(), 0);
if (pos > -1)
{
str = str.Substring(pos);
}
else
{
str = str.Substring(str.Length);
}
}
else
{
StackElement st = new StackElement(lookahead);
st.state = tableValue;
stack.Push(st);
str = str.Substring(1);
}
return;
}
// else case
Console.WriteLine("Error encountered while parsing the template!");
Console.WriteLine("Shift rule not defined for lookahead char {0} in state {1}", lookahead, topElement.state);
Debug.Assert(false);
}
// reduce operation
if (reduce.TryGetValue(topElement.state, out tableRow))
{
int tableValue;
if (tableRow.TryGetValue(lookahead, out tableValue))
{
switch (tableValue)
{
// which reduce rule do we have to apply?
case 1:
{
StackElement rightBracket = stack.Pop();
Debug.Assert(rightBracket.t == StackElementType.charType);
Debug.Assert(rightBracket.charVal == ')');
StackElement template = stack.Pop();
Debug.Assert(template.t == StackElementType.templateType);
StackElement leftBracket = stack.Pop();
Debug.Assert(leftBracket.t == StackElementType.charType);
Debug.Assert(leftBracket.charVal == '(');
int newState = goto_actions[stack.Peek().state]['t'];
StackElement st = new StackElement(template.tempVal);
st.state = newState;
template.tempVal = null;
stack.Push(st);
break;
}
case 2:
{
StackElement rightTemp = stack.Pop();
Debug.Assert(rightTemp.t == StackElementType.templateType);
StackElement semi_colon = stack.Pop();
Debug.Assert(semi_colon.t == StackElementType.charType);
Debug.Assert(semi_colon.charVal == ';');
StackElement leftTemp = stack.Pop();
Debug.Assert(leftTemp.t == StackElementType.templateType);
StackElement st = new StackElement(new Template(TemplateOperator.DisjunctionOp, leftTemp.tempVal, rightTemp.tempVal));
int newState = goto_actions[stack.Peek().state]['t'];
st.state = newState;
leftTemp.tempVal = null;
rightTemp.tempVal = null;
stack.Push(st);
break;
}
case 3:
{
StackElement rightTemp = stack.Pop();
Debug.Assert(rightTemp.t == StackElementType.templateType);
StackElement comma = stack.Pop();
Debug.Assert(comma.t == StackElementType.charType);
Debug.Assert(comma.charVal == ',');
StackElement leftTemp = stack.Pop();
Debug.Assert(leftTemp.t == StackElementType.templateType);
StackElement st = new StackElement(new Template(TemplateOperator.ConjunctionOp, leftTemp.tempVal, rightTemp.tempVal));
int newState = goto_actions[stack.Peek().state]['t'];
st.state = newState;
leftTemp.tempVal = null;
rightTemp.tempVal = null;
stack.Push(st);
break;
}
case 4:
{
StackElement intElement = stack.Pop();
Debug.Assert(intElement.t == StackElementType.intType);
int newstate = goto_actions[stack.Peek().state]['t'];
StackElement st = new StackElement(new Template(intElement.intVal));
st.state = newstate;
stack.Push(st);
break;
}
default:
Console.WriteLine("Error encountered while parsing the template!");
Console.WriteLine("Unknown reduction rule sought.");
Debug.Assert(false);
break;
}
return;
}
else
{
Console.WriteLine("Error encountered while parsing the template!");
Console.WriteLine("reduce rule not defined for lookahead char {0} in state {1}", lookahead, topElement.state);
Debug.Assert(false);
}
}
else
{
Console.WriteLine("Error encountered while parsing template!");
Console.WriteLine("No entry in ParserTable corresponding to the current state {0} on top of the stack.", topElement.state);
Debug.Assert(false);
}
return;
}
public static Template Parse()
{
StackElement st = new StackElement();
st.state = 0;
stack.Push(st);
char lookahead;
int intVal;
invokeLexer(out lookahead, out intVal);
while(stack.Peek().state != 1 || lookahead != '$')
{
processOneStep(lookahead, intVal);
invokeLexer(out lookahead, out intVal);
}
Template ret = stack.Peek().tempVal;
stack.Peek().tempVal = null;
return ret;
}
