public bool Matches(Token t)
{
if (matchedTokenType != null)
return t.Type == matchedTokenType;
else
return t.Lexeme == matchedString;
}
// or from a nonterminal and a token, in which case we need to check
// all the terminals for the given nonterminal and see if one matches the token
public ISymbol[] Get(Nonterminal var, Token token)
{
Dictionary<Terminal, ISymbol[]> tableRow = table[var];
foreach (Terminal term in tableRow.Keys)
if (term.Matches(token))
return tableRow[term];
return null;
}
public ReadStmt(string identifier, Token token)
: base(token)
{
this.identifier = identifier;
}
public PrintStmt(Expression expr, Token token)
: base(token)
{
this.expr = expr;
}
public ForStmt(string identifier, Expression startVal, Expression endVal, IEnumerable<Statement> block, Token token)
: base(token)
{
this.identifier = identifier;
this.startVal = startVal;
this.endVal = endVal;
this.block = block;
}
public LexicalError(Token t)
: base(t)
{
}
public RuntimeError(Token t, string description)
: base(t)
{
this.description = description;
}
// recall the last valid token
private Token TakeToken()
{
Token t = lastToken;
lastToken = null;
row = endRow;
col = endCol;
startRow = endRow;
startCol = endCol;
return t;
}
public ValueExpr(Value value, Token token)
: base(token)
{
this.value = value;
}
public UnaryOp(char op, Expression expr, Token token)
: base(token)
{
this.op = op; this.expr = expr;
}
public IdentifierExpr(string identifier, Token token)
: base(token)
{
this.identifier = identifier;
}
// Every expression contains token to identify location in code
Expression(Token token)
{
this.token = token;
}
public BinaryOp(Expression lhs, char op, Expression rhs, Token token)
: base(token)
{
this.op = op;
this.lhs = lhs;
this.rhs = rhs;
}
public SyntaxError(Token t)
: base(t)
{
}
// resets the automaton to its initial state
public void Reset()
{
row = 0;
col = 0;
endRow = 0;
endCol = 0;
startRow = 0;
startCol = 0;
tokenBuffer = new Queue<Token>();
lastToken = null;
position = start;
}
// remember the last valid token
private void StoreToken(TokenType type)
{
lastToken = type.CreateToken(charBuffer, startRow, startCol);
endRow = row;
endCol = col;
}
public AssignStmt(string identifier, Expression expr, Token token)
: base(token)
{
this.identifier = identifier;
this.expr = expr;
}
// Every statement contains token to identify location in code
Statement(Token token)
{
this.token = token;
}
public DeclarationStmt(string identifier, ValueType type, Token token, Expression initialValue)
: this(identifier, type, token)
{
this.initialValue = initialValue;
}
// just checks if a token should be yielded by the generator
private bool IsRelevant(Token t, bool EOFisRelevant)
{
return (t.Type.TokenPriority != TokenType.Priority.Whitespace && (t.Type != TokenType.EOF || EOFisRelevant));
}
public DeclarationStmt(string identifier, ValueType type, Token token)
: base(token)
{
this.identifier = identifier;
this.type = type;
}
public SemanticError(Token t, string description)
: base(t)
{
this.description = description;
}
protected Error(Token t)
{
this.t = t;
}