bool CanParse(Precedence context, int li, out Precedence prec)
{
var opTok = LT(li);
if (opTok.Type() == TokenType.Id)
{
var opTok2 = LT(li + 1);
if (opTok2.Type() == TokenType.NormalOp && opTok.EndIndex == opTok2.StartIndex)
{
prec = _prec.Find(OperatorShape.Infix, opTok2.Value);
}
else
{
// Oops, LesPrecedenceMap doesn't yet support non-single-quote ops
// (bacause it's shared with LESv2 which doesn't have them)
// TODO: improve performance by avoiding this concat
prec = _prec.Find(OperatorShape.Infix, (Symbol)("'" + opTok.Value.ToString()));
}
}
else
{
prec = _prec.Find(OperatorShape.Infix, opTok.Value);
}
bool result = context.CanParse(prec);
if (!context.CanMixWith(prec))
{
Error(li, "Operator \"{0}\" cannot be mixed with the infix operator to its left. Add parentheses to clarify the code's meaning.", LT(li).Value);
}
return(result);
}
// Checks if an operator with precedence 'prec' can appear in this context.
bool CanAppearHere(Precedence prec, out bool extraParens, bool prefix = false)
{
extraParens = false;
if (prec.CanAppearIn(_context, prefix) && (prefix || _o.MixImmiscibleOperators || prec.CanMixWith(_context)))
return true;
if (_n.IsParenthesizedExpr())
return true;
if (_o.AllowChangeParentheses || !EP.Primary.CanAppearIn(_context)) {
Trace.WriteLineIf(!_o.AllowChangeParentheses, "Forced to write node in parens");
return extraParens = true;
}
return false;
}
// Checks if an operator with precedence 'prec' can appear in this context.
bool CanAppearIn(Precedence prec, Precedence context, out bool extraParens, bool prefix = false)
{
extraParens = false;
if (prec.CanAppearIn(context, prefix) && (prefix || MixImmiscibleOperators || prec.CanMixWith(context)))
{
return(true);
}
if (_n.IsParenthesizedExpr())
{
return(true);
}
if (AllowChangeParenthesis || !EP.Primary.CanAppearIn(context))
{
Trace.WriteLineIf(!AllowChangeParenthesis, "Forced to write node in parens");
return(extraParens = true);
}
return(false);
}
