public static Program Parse(string script)
{
var instructions = new Dictionary <string, Instruction>();
var tokens = new TokenQueue(Tokenizer.Tokenize(script));
var token = tokens.GetNext();
while (!token.IsEndOfScript())
{
var instruction = ToInstruction(token, tokens);
token = tokens.GetNext();
var wireName = string.Empty;
while (!token.IsEndOfLine())
{
switch (token.TokenType)
{
case TokenType.Assign:
instruction = AssignInstruction(tokens, instruction);
wireName = tokens.GetCurrent().Value;
break;
case TokenType.And:
instruction = AndInstruction(tokens, instruction);
break;
case TokenType.Or:
instruction = OrInstruction(tokens, instruction);
break;
case TokenType.Not:
instruction = NotInstruction(tokens);
break;
case TokenType.LShift:
instruction = LShiftInstruction(tokens, instruction);
break;
case TokenType.RShift:
instruction = RShiftInstruction(tokens, instruction);
break;
}
token = tokens.GetNext();
}
instructions.Add(wireName, instruction);
token = tokens.GetNext();
}
return(new Program(instructions));
}
private static Instruction ToInstruction(Token token, TokenQueue tokens)
{
Func <Instruction> func = token.TokenType switch
{
TokenType.Number => () => new NumberInstruction(ushort.Parse(token.Value)),
TokenType.WireName => () => new GetWireInstruction(token.Value),
TokenType.Not => () =>
{
var rightToken = tokens.GetNext();
return(new NotInstruction(new GetWireInstruction(rightToken.Value)));
},
_ => () => new NullInstruction()
};
return(func());
}
}
private static Instruction AssignInstruction(TokenQueue tokens, Instruction instruction)
{
var rightToken = tokens.GetNext();
return(new AssignInstruction(instruction, new GetWireInstruction(rightToken.Value)));
}
private static Instruction AndInstruction(TokenQueue tokens, Instruction instruction)
{
var rightToken = tokens.GetNext();
return(new AndInstruction(instruction, ToInstruction(rightToken, tokens)));
}
private static Instruction NotInstruction(TokenQueue tokens)
{
var rightToken = tokens.GetNext();
return(new NotInstruction(ToInstruction(rightToken, tokens)));
}
private static Instruction LShiftInstruction(TokenQueue tokens, Instruction instruction)
{
var rightToken = tokens.GetNext();
return(new LeftShiftInstruction(instruction, ToInstruction(rightToken, tokens)));;
}