// power: atom trailer* ['**' factor]
private Expression ParsePower() {
Expression ret = ParsePrimary();
ret = AddTrailers(ret);
if (MaybeEat(TokenKind.Power)) {
var start = ret.StartIndex;
ret = new BinaryExpression(PythonOperator.Power, ret, ParseFactor());
ret.SetLoc(_globalParent, start, GetEnd());
}
return ret;
}
private Expression ParseExpr(int precedence) {
Expression ret = ParseFactor();
while (true) {
Token t = PeekToken();
OperatorToken ot = t as OperatorToken;
if (ot == null) return ret;
int prec = ot.Precedence;
if (prec >= precedence) {
NextToken();
Expression right = ParseExpr(prec + 1);
var start = ret.StartIndex;
ret = new BinaryExpression(GetBinaryOperator(ot), ret, right);
ret.SetLoc(_globalParent, start, GetEnd());
} else {
return ret;
}
}
}
// power: atom trailer* ['**' factor]
private Expression ParsePower() {
Expression ret = ParsePrimary();
ret = AddTrailers(ret);
if (MaybeEat(TokenKind.Power)) {
SourceLocation start = ret.Start;
ret = new BinaryExpression(PythonOperator.Power, ret, ParseFactor());
ret.SetLoc(start, GetEnd());
}
return ret;
}
//comparison: expr (comp_op expr)*
//comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
private Expression ParseComparison() {
Expression ret = ParseExpr();
while (true) {
PythonOperator op;
switch (PeekToken().Kind) {
case TokenKind.LessThan: NextToken(); op = PythonOperator.LessThan; break;
case TokenKind.LessThanOrEqual: NextToken(); op = PythonOperator.LessThanOrEqual; break;
case TokenKind.GreaterThan: NextToken(); op = PythonOperator.GreaterThan; break;
case TokenKind.GreaterThanOrEqual: NextToken(); op = PythonOperator.GreaterThanOrEqual; break;
case TokenKind.Equals: NextToken(); op = PythonOperator.Equal; break;
case TokenKind.NotEquals: NextToken(); op = PythonOperator.NotEqual; break;
case TokenKind.LessThanGreaterThan: NextToken(); op = PythonOperator.NotEqual; break;
case TokenKind.KeywordIn: NextToken(); op = PythonOperator.In; break;
case TokenKind.KeywordNot: NextToken(); Eat(TokenKind.KeywordIn); op = PythonOperator.NotIn; break;
case TokenKind.KeywordIs:
NextToken();
if (MaybeEat(TokenKind.KeywordNot)) {
op = PythonOperator.IsNot;
} else {
op = PythonOperator.Is;
}
break;
default:
return ret;
}
Expression rhs = ParseComparison();
BinaryExpression be = new BinaryExpression(op, ret, rhs);
be.SetLoc(_globalParent, ret.StartIndex, GetEnd());
ret = be;
}
}
private Expression ParseExpr(int precedence)
{
Expression ret = ParseFactor();
while (true) {
Token t = PeekToken();
OperatorToken ot = t as OperatorToken;
if (ot == null) return ret;
int prec = ot.Operator.Precedence;
if (prec >= precedence) {
NextToken();
Expression right = ParseExpr(prec + 1);
Location start = ret.Start;
ret = new BinaryExpression((BinaryOperator)ot.Operator, ret, right);
ret.SetLoc(GetExternal(), start, GetEnd());
} else {
return ret;
}
}
}