public SScope SpawnScopeWith(String[] names, SObject[] values)
{
//(names.Length >= values.Length).OrThrows("Too many arguments.");
SScope scope = new SScope(this);
for (Int32 i = 0; i < values.Length; i++)
{
scope.variableTable.Add(names[i], values[i]);
}
return(scope);
}
public SObject Find(String name)
{
SScope current = this;
while (current != null)
{
if (current.variableTable.ContainsKey(name))
{
return(current.variableTable[name]);
}
current = current.Parent;
}
throw new Exception(name + " is not defined.");
}
public SObject Evaluate(SScope scope)
{
if (this.Children.Count == 0)
{
Int64 number;
if (Int64.TryParse(this.Value, out number))
{
return(number);
}
}
else
{
SExpression first = this.Children[0];
if (SScope.BuiltinFunctions.ContainsKey(first.Value))
{
var arguments = this.Children.Skip(1).ToArray();
return(SScope.BuiltinFunctions[first.Value](arguments, scope));
}
}
throw new Exception("THIS IS JUST TEMPORARY!");
}
public static void KeepInterpretingInConsole(this SScope scope, Func <String, SScope, SObject> evaluate)
{
while (true)
{
try
{
Console.ForegroundColor = ConsoleColor.Gray;
Console.Write(">> ");
String code;
if (!String.IsNullOrWhiteSpace(code = Console.ReadLine()))
{
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine(">> " + evaluate(code, scope));
}
}
catch (Exception ex)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine(">> " + ex.Message);
}
}
}
static void Main(string[] cmdArgs)
{
Console.WriteLine("解释器：");
//Output(Input());
SScope sScope = new SScope(parent: null)
.BuildIn("+", (args, scope) =>
{
var numbers = args.Select(obj => obj.Evaluate(scope)).Cast <SNumber>();
return(numbers.Sum(n => n));
})
.BuildIn("-", (args, scope) =>
{
var numbers = args.Select(obj => obj.Evaluate(scope)).Cast <SNumber>().ToArray();
Int64 firstValue = numbers[0];
if (numbers.Length == 1)
{
return(-firstValue);
}
return(firstValue - numbers.Skip(1).Sum(s => s));
});
KeepInterpretingInConsole(sScope, (code, scope) => ParseAsIScheme(code).Evaluate(scope));
}
public SFunction(SExpression sExpression, String[] parameters, SScope scope)
{
this.Body = sExpression;
this.Parameters = parameters;
this.Scope = scope;
}
public static IEnumerable <SObject> Evaluate(this IEnumerable <SExpression> expressions, SScope scope)
{
return(expressions.Select(exp => exp.Evaluate(scope)));
}
public static IEnumerable <T> Evaluate <T>(this IEnumerable <SExpression> expressions, SScope scope)
where T : SObject
{
return(expressions.Evaluate(scope).Cast <T>());
}
public SScope(SScope parent)
{
this.Parent = parent;
this.variableTable = new Dictionary <string, SObject>();
}