/// <summary>
/// Creates a new parser
/// </summary>
/// <param name="tokens">The tokens</param>
/// <param name="binaryOperatorPrecedences">The binary operator precedence table</param>
public Parser(IEnumerable<Token> tokens, IDictionary<char, int> binaryOperatorPrecedences = null)
{
this.tokens = tokens;
this.currentToken = null;
if (binaryOperatorPrecedences == null)
{
this.binaryOperatorPrecedence = new Dictionary<char, int>();
}
else
{
this.binaryOperatorPrecedence = binaryOperatorPrecedences;
}
//This operators must exist
if (!this.binaryOperatorPrecedence.ContainsKey('<'))
{
this.binaryOperatorPrecedence.Add('<', 10);
}
if (!this.binaryOperatorPrecedence.ContainsKey('+'))
{
this.binaryOperatorPrecedence.Add('+', 20);
}
if (!this.binaryOperatorPrecedence.ContainsKey('-'))
{
this.binaryOperatorPrecedence.Add('-', 20);
}
if (!this.binaryOperatorPrecedence.ContainsKey('*'))
{
this.binaryOperatorPrecedence.Add('*', 40);
}
}
/// <summary>
/// Advances to the next token
/// </summary>
private void NextToken()
{
this.currentToken = this.tokens.FirstOrDefault();
this.tokens = this.tokens.Skip(1);
}
