/// <summary>
/// Parses S-Expressions and builds an internal representation.
/// Named after the 'analyze procedure from SICP #4.1.7.
/// </summary>
/// <param name="sExpr"></param>
/// <returns></returns>
public static Expression Analyze(SExpression sExpression)
{
// Dispatch on S-Expression's type
if (sExpression is SAtom atom)
{
if (NumberExpression.IsInstance(atom))
{
return(NumberExpression.Analyze(atom));
}
else if (StringExpression.IsInstance(atom))
{
return(StringExpression.Analyze(atom));
}
else if (BooleanExpression.IsInstance(atom))
{
return(BooleanExpression.Analyze(atom));
}
else
{
return(Variable.Analyze(atom));
}
}
else
{
var list = (SList)sExpression;
if (list.Count == 0)
{
throw new BadSyntaxException("procedure application", "Empty application", list.Text);
}
string head = list[0].Text;
if (SpecialForm.Table.ContainsKey(head))
{
// $list is a special form
Func <SList, SpecialForm> spFormAnalyzer = SpecialForm.Table[head];
return(spFormAnalyzer(list));
}
else
{
// $list is a procedure application
return(Application.Analyze(list));
}
}
}