/*
* Below are the functions used to generate AST nodes.
* They can throw ParserException to indicate of an error.
* They can return null to indicate that lexeme did not match.
* Otherwise they return an AST node.
* They consume Lexemes.
*
* The function names reflect the ones used in the grammar.
*/
ASTNode NUM()
{
var lexeme = Consume(TokenType.NUMBER);
var node = new NumberNode(lexeme.token);
node.lexeme = lexeme;
return(node);
}
public NumberValue VisitNumberNode(NumberNode node, Context context)
{
return new NumberValue() { Value = (int)node.NumberToken.Value };
}