string parseTernary(string s) {
if (s.length() <= 1) return s;
int level = 0;
char c = s[0];
for (int i = 1; i < s.length(); i++) {
if (s[i] == '?') level++;
else if (s[i] == ':') {
if (--level == 0) return c == 'T' ? parseTernary(s.substr(2, i-2)) : parseTernary(s.substr(i+1));
}
}
return "";
}
Expression* parseTernary(TokenStream* tokens, FileContext* fileContext)
{
Expression* expression = parseInequality(tokens, fileContext);
if (tokens->safePeekValue() == "?")
{
Token questionToken = tokens->pop();
Expression* trueExpression = parseTernary(tokens, fileContext);
tokens->popExpected(":");
Expression* falseExpression = parseTernary(tokens, fileContext);
expression = new Ternary(expression, questionToken, trueExpression, falseExpression, fileContext);
}
return expression;
}
string parseTernary(string expression) {
// start coding at 10:40
int que = 0;
while (que < expression.size() && expression[que] != '?') que += 1;
if (que == expression.size()) return expression;
int col = que+1;
int qCount = 0;
while (expression[col] != ':' || qCount) {
if (expression[col] == '?') qCount += 1;
if (expression[col] == ':') qCount -= 1;
col += 1;
}
if (expression[0] == 'T') return parseTernary(expression.substr(que+1, col-que-1));
else return parseTernary(expression.substr(col+1, expression.size()-col-1));
}
// This function doesn't do anything special, but it's easier to call this instead
// of remembering that parseTernary is the outermost of the order of operations.
Expression* parseExpression(TokenStream* tokens, FileContext* fileContext)
{
return parseTernary(tokens, fileContext);
}
