private static void HandleAlternative(StringBuilder codeStringBuilder, Rule rule, Alternative alt, List<string> vars, List<string> items)
{
// TODO: to solve the infinite recursion problem i am seeing i need to come up with
// TODO: a general version of the code seen in GrammarParser:Metas() or GrammarParser:Rules()
// TODO: and also determine when to apply that form vs. the form i already have.
// detect a right recursive alternative
if (alt.Items[alt.Items.Count - 1] == rule.Name)
{
HandleRightRecursiveAlternative(codeStringBuilder, rule, alt, items, vars);
}
else
{
HandleStandardAlternative(codeStringBuilder, rule, alt, items, vars);
}
}
private static void HandleRightRecursiveAlternative(StringBuilder codeStringBuilder, Rule rule, Alternative alt, List<string> items, List<string> vars)
{
System.Console.WriteLine("Right recursive rule alternative detected.");
string _var = CreateVar(codeStringBuilder, alt.Items[0], items, vars);
codeStringBuilder.Append("if(");
codeStringBuilder.Append($"{_var} != null");
codeStringBuilder.AppendLine(") {");
// further condition matching here
foreach (string _item in alt.Items.GetRange(1, alt.Items.Count - 1))
{
if (_item != alt.Items[alt.Items.Count - 1])
{
CreateVar(codeStringBuilder, _item, items, vars);
}
else
{
codeStringBuilder.AppendLine($"List<Object> _{_item} = new List<Object>();");
codeStringBuilder.AppendLine($"_{_item}.Add({_var});");
codeStringBuilder.AppendLine($"List<Object> _new{_item} = (List<Object>)Memoize({_item});");
codeStringBuilder.Append($"if(_new{_item} != null");
codeStringBuilder.AppendLine(") {");
codeStringBuilder.AppendLine($"_{_item}.AddRange(_new{_item});");
codeStringBuilder.AppendLine($"Console.WriteLine(\"Recognized [ {rule.Name} ]\");");
codeStringBuilder.AppendLine("return true;");
codeStringBuilder.AppendLine("}");
}
AddComment(codeStringBuilder, $"return _{_item}");
}
codeStringBuilder.AppendLine("}");
}
private static void HandleStandardAlternative(StringBuilder codeStringBuilder, Rule rule, Alternative alt, List<string> items, List<string> vars)
{
foreach (string _item in alt.Items)
{
CreateVar(codeStringBuilder, _item, items, vars);
}
codeStringBuilder.Append("if(");
foreach (string var in items)
{
if (var != items[items.Count - 1])
{
codeStringBuilder.Append($"{var} != null && ");
}
else
{
codeStringBuilder.Append($"{var} != null");
}
}
codeStringBuilder.AppendLine(") {");
codeStringBuilder.AppendLine($"Console.WriteLine(\"Recognized [ {rule.Name} ]\");");
/*
TODO: write node returning code here
*/
codeStringBuilder.AppendLine("return true;");
codeStringBuilder.AppendLine("}");
}
