private ConsCell Read()
{
if (tokens.Count == 0)
{
return(ConsCell.Nil);
}
var token = tokens.Dequeue();
if (token == "(")
{
openingParensCount++;
var car = Read();
var cdr = Read();
return(new ConsCell(car, cdr));
}
if (token == ")")
{
openingParensCount--;
return(ConsCell.Nil);
}
if (token == "'")
{
var caar = Atom.Parse("quote");
var next = Read();
var cadr = new ConsCell(next.Car, ConsCell.Nil);
var car = new ConsCell(caar, cadr);
var cdr = next.Cdr;
return(new ConsCell(car, cdr));
}
{
var car = Atom.Parse(token);
var cdr = Read();
return(new ConsCell(car, cdr));
}
}
/// <summary>
/// Initializes a new instance of the <see cref="EmptyMatcher{TValue, TResult}" /> class.
/// </summary>
/// <param name="funcIfConsCell">The function that is executed if this list is a cons cell.</param>
internal EmptyMatcher(Func <TValue, ConsList <TValue>, TResult> funcIfConsCell)
{
this.cell = null;
this.isCellPresent = default;
this.funcIfConsCell = funcIfConsCell;
}
/// <summary>
/// Initializes a new instance of the <see cref="EmptyMatcher{TValue, TResult}" /> class.
/// </summary>
/// <param name="cell">The cell to provide to the function.</param>
/// <param name="funcIfConsCell">The function that is executed if this list is a cons cell.</param>
internal EmptyMatcher(ConsCell <TValue> cell, Func <TValue, ConsList <TValue>, TResult> funcIfConsCell)
{
this.cell = cell;
this.isCellPresent = true;
this.funcIfConsCell = funcIfConsCell;
}
/// <summary>
/// Initializes a new instance of the <see cref="ConsCellMatcher{TValue, TResult}" /> class.
/// </summary>
/// <param name="funcIfEmpty">The function that is executed if this list is empty.</param>
internal ConsCellMatcher(Func <TResult> funcIfEmpty)
{
this.cell = null;
this.isCellPresent = false;
this.funcIfEmpty = funcIfEmpty;
}
/// <summary>
/// Initializes a new instance of the
/// <see cref="ConsCellMatcher{TValue, TResult}" /> class.
/// </summary>
/// <param name="cell">The cell to provide to the function.</param>
/// <param name="funcIfEmpty">The function that is executed if this list is empty.</param>
internal ConsCellMatcher(ConsCell <TValue> cell, Func <TResult> funcIfEmpty)
{
this.cell = cell;
this.isCellPresent = true;
this.funcIfEmpty = funcIfEmpty;
}