/// <summary>
/// Parses a conditional statement.
/// </summary>
public ParseResult ParseConditional(List <Token> tokens)
{
var node = new ConditionalNode();
var scopeCheck = new ScopeCheck();
for (int i = 0; i < tokens.Count; i++)
{
var token = tokens[i];
scopeCheck.Check(token);
if (token.Equals("?", TokenTypes.Punctuator) && scopeCheck.IsInScope)
{
SkipInfo skip = SkipFromTo("?", ":", tokens, i);
var conditionNode = ParseClean(tokens.GetRange(0, i));
var successNode = ParseClean(tokens.GetRange(i + 1, skip.Delta - 1));
var failNode = ParseClean(tokens.GetRange(skip.End + 1, tokens.Count - (skip.End + 1)));
node.Condition = conditionNode ?? throw new SkryptException("Syntax error, condition statement can't be empty");
node.Pass = successNode ?? throw new SkryptException("Syntax error, consequent statement can't be empty");
node.Fail = failNode ?? throw new SkryptException("Syntax error, alternative statement can't be empty");
return(new ParseResult {
Node = node, Delta = tokens.Count
});
}
}
_engine.ThrowError("Syntax error, conditional statement incomplete", tokens[0]);
return(null);
}
// Checks whether a list of tokens is a valid conditional statement.
private bool IsConditional(List <Token> tokens)
{
var isConditional = false;
var scopeCheck = new ScopeCheck();
for (int i = 0; i < tokens.Count; i++)
{
var token = tokens[i];
scopeCheck.Check(token);
if (token.Equals("?", TokenTypes.Punctuator) && scopeCheck.IsInScope)
{
isConditional = true;
SkipInfo skip = SkipFromTo("?", ":", tokens, i);
}
}
return(isConditional);
}