private Parsen MaybeBinary(Parsen left, int myPrec)
{
var tok = _input.Peek( );
if (IsOp(null))
{
var hisPrec = PRECENDENCE[(string)tok["value"]];
if (hisPrec > myPrec)
{
_input.Next( );
return MaybeBinary(
new Parsen( )
{
{ "type", (string)tok["value"] == "=" || (string)tok["value"] == "->" ? "assign" : "binary"},
{ "oper", (string)tok["value"]},
{ "left", left },
{ "right", MaybeBinary(ParseAtom( ), hisPrec) } }, myPrec
);
}
}
return left;
}
private Parsen ParseIf( )
{
SkipKw("if");
var cond = ParseExpr( );
if (!IsPunc('{'))
throw new Exception( );
var then = ParseExpr( );
var ret = new Parsen( )
{
{ "type", "if" },
{ "cond", cond },
{ "then", then }
};
if (IsKw("else"))
{
_input.Next( );
ret["else"] = ParseExpr( );
}
return ret;
}