private bool ReadStringValue(StringReader p, out ExprPiece value)
{
string s;
if (p.AnyQuoted(out s))
{
value = new LiteralConst
{
Literal = s
};
return true;
}
value = null;
return false;
}
private bool ReadSymbolValue(StringReader p, out ExprPiece value)
{
int wordRead;
if (p.ThisWord(new[] { "null", "true", "false" }, out wordRead))
switch (wordRead)
{
case 0:
value = new LiteralConst { Literal = null };
return true;
case 1:
value = new LiteralConst { Literal = true };
return true;
case 2:
value = new LiteralConst { Literal = false };
return true;
}
value = null;
return false;
}
private bool ReadFloatValue(StringReader p, out ExprPiece value)
{
var saved = p.Position;
p.Skip();
string f;
// sinal
char sig;
if (p.ThisCharNoSkip("+-", out sig))
f = sig.ToString();
else
f = "";
bool hasint = false, hasfrac = false, hasexp = false;
// int part
string intpart;
if (p.ThisSetNoSkip("0123456789", out intpart))
{
f += intpart;
hasint = true;
}
else
f += "0";
var befpt = p.Position;
// frac part
if (p.ThisCharNoSkip('.'))
{
string fracpart;
if (p.ThisSetNoSkip("0123456789", out fracpart))
{
f += "." + fracpart;
hasfrac = true;
}
if (!hasfrac)
p.Position = befpt;
}
// exp part
if (hasint || hasfrac)
{
var befexp = p.Position;
if (p.ThisCharNoSkip("eE"))
{
char expsig;
if (p.ThisCharNoSkip("+-", out expsig))
{
string exppart;
if (p.ThisSetNoSkip("0123456789", out exppart))
{
f += "e" + expsig.ToString() + exppart;
hasexp = true;
}
}
if (!hasexp)
p.Position = befexp;
}
var lit = new LiteralConst();
int ival;
if (hasfrac)
{
var comma = 1.1.ToString()[1];
f = f.Replace('.', comma);
lit.Literal = double.Parse(f);
}
else if (int.TryParse(f, out ival))
lit.Literal = ival;
else
lit.Literal = long.Parse(f);
value = lit;
return true;
}
p.Position = saved;
value = null;
return false;
}
