IEnumerable<ProductionModel> Repetition(EbnfFactorRepetition repetition, ProductionModel currentProduction)
{
var name = repetition.ToString();
var nonTerminal = new NonTerminal(name);
var repetitionProduction = new ProductionModel(nonTerminal);
currentProduction.AddWithAnd(new NonTerminalModel(nonTerminal));
var expression = repetition.Expression;
foreach (var production in Expression(expression, repetitionProduction))
yield return production;
repetitionProduction.AddWithAnd(new NonTerminalModel(nonTerminal));
repetitionProduction.Lambda();
yield return repetitionProduction;
}
IEnumerable<ProductionModel> Expression(EbnfExpression expression, ProductionModel currentProduction)
{
foreach (var production in Term(expression.Term, currentProduction))
yield return production;
if (expression.NodeType != EbnfNodeType.EbnfExpressionAlteration)
yield break;
var expressionAlteration = expression as EbnfExpressionAlteration;
currentProduction.Lambda();
foreach (var production in Expression(expressionAlteration.Expression, currentProduction))
yield return production;
}
IEnumerable<ProductionModel> Optional(EbnfFactorOptional optional, ProductionModel currentProduction)
{
var name = optional.ToString();
var nonTerminal = new NonTerminal(name);
var optionalProduction = new ProductionModel(nonTerminal);
currentProduction.AddWithAnd(new NonTerminalModel(nonTerminal));
var expression = optional.Expression;
foreach (var production in Expression(expression, optionalProduction))
yield return production;
optionalProduction.Lambda();
yield return optionalProduction;
}