private IEnumerable <ProductionModel> Expression(IEbnfExpression expression, ProductionModel currentProduction)
{
foreach (var production in Term(expression.Term, currentProduction))
{
yield return(production);
}
if (expression is EbnfExpressionAlteration expressionAlteration)
{
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);
}
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);
}
}
