public object visitTernaryExpr(Expr.TernaryExpr ternaryExpr)
{
resolve(ternaryExpr.comparisonExpression);
resolve(ternaryExpr.falseExpression);
resolve(ternaryExpr.trueExpression);
return(null);
}
public object visitTernaryExpr(Expr.TernaryExpr ternaryExpr)
{
bool comparisonExpression = (bool)evaluate(ternaryExpr.comparisonExpression);
if (comparisonExpression)
{
return(evaluate(ternaryExpr.trueExpression));
}
else
{
return(evaluate(ternaryExpr.falseExpression));
}
}
private Expr ternaryExpression()
{
Expr expr = isNull(); //Comparison expression
Expr trueExpression; //Result if comparison is true
if (match(TokenType.TERNARY_QUESTION))
{
trueExpression = isNull();
if (match(TokenType.TERNARY_COLON))
{
Expr falseExpression = isNull(); //Result if comparison is false.
Expr temp = expr;
expr = new Expr.TernaryExpr(temp, trueExpression, falseExpression);
}
}
return(expr);
}
private Expr call()
{
Expr expr = primary();
while (true)
{
if (match(TokenType.LEFT_PAREN))
{
expr = finishCall(expr);
}
else if (match(TokenType.DOT))
{
Token name = consume(TokenType.IDENTIFIER, "Expect property name after '.'.");
expr = new Expr.Get(expr, name, false);
}
else if (match(TokenType.QUESTION_DOT))
{
Token nil = new Token(TokenType.NIL, "nil", null, -1, -1);
Expr callIfNotNull = new Expr.Get(expr, consume(TokenType.IDENTIFIER, "Expect property after '?."), false);
if (match(TokenType.LEFT_PAREN))
{
callIfNotNull = finishCall(callIfNotNull);
}
expr = new Expr.TernaryExpr(
new Expr.BinaryExpr(expr, new Token(TokenType.EQUALS_EQUALS, "==", null, -1, -1), new Expr.Literal(null, nil)), // ?
new Expr.Literal(null, nil), // :
callIfNotNull); // new Expr.Get(expr, consume(TokenType.IDENTIFIER, "Expect property after '?."), false));
((Expr.TernaryExpr)expr).isNullAccessor = true;
}
else
{
break;
}
}
return(expr);
}
public string visitTernaryExpr(Expr.TernaryExpr expr)
{
return(parenthesize("?:", new Expr[] { expr.comparisonExpression, expr.trueExpression, expr.falseExpression }));
}
