// ( (ASSIGN^ logicalOrExpression)
// | (DEFAULT^ logicalOrExpression)
// | (QMARK^ expression COLON! expression)
// | (ELVIS^ expression))?;
private SpelNodeImpl eatExpression() {
SpelNodeImpl expr = eatLogicalOrExpression();
if (moreTokens()) {
Token t = peekToken();
if (t.kind == TokenKind.ASSIGN) { // a=b
if (expr == null) {
expr = new NullLiteral(toPos(t.startPos - 1, t.endPos - 1));
}
nextToken();
SpelNodeImpl assignedValue = eatLogicalOrExpression();
return new Assign(toPos(t), expr, assignedValue);
}
if (t.kind == TokenKind.ELVIS) { // a?:b (a if it isn't null, otherwise b)
if (expr == null) {
expr = new NullLiteral(toPos(t.startPos - 1, t.endPos - 2));
}
nextToken(); // elvis has left the building
SpelNodeImpl valueIfNull = eatExpression();
if (valueIfNull==null) {
valueIfNull = new NullLiteral(toPos(t.startPos + 1, t.endPos + 1));
}
return new Elvis(toPos(t), expr, valueIfNull);
}
if (t.kind == TokenKind.QMARK) { // a?b:c
if (expr == null) {
expr = new NullLiteral(toPos(t.startPos - 1, t.endPos - 1));
}
nextToken();
SpelNodeImpl ifTrueExprValue = eatExpression();
eatToken(TokenKind.COLON);
SpelNodeImpl ifFalseExprValue = eatExpression();
return new Ternary(toPos(t), expr, ifTrueExprValue, ifFalseExprValue);
}
}
return expr;
}