protected override EvalResult EvalImpl(ScmEnvironment env)
{
ScmExpression result = null;
foreach (var scmExpression in _exprs)
{
result = scmExpression.Eval(env).Value;
}
return(result.ToResult());
}
private bool True(ScmExpression exp)
{
var selfExp = exp as SelfEvaluatingExpression;
return(selfExp != null && selfExp.Value is bool && (bool)selfExp.Value);
}
private void DefineVariable(string var, ScmExpression val, ScmEnvironment env)
{
env.Dict[var] = val;
}
public IfExpression(ScmExpression predicate, ScmExpression then, ScmExpression @else)
{
_else = @else;
_then = then;
_predicate = predicate;
}
public ApplicationExpression(ScmExpression @operator, ScmExpression[] arguments)
{
Operator = @operator;
Arguments = arguments;
}
private void SetVariable(object variable, ScmExpression eval, ScmEnvironment env)
{
}
public AssignmentExpression(object variable, ScmExpression value)
{
_variable = variable;
_value = value;
}
public LambdaExpression(ScmExpression body, string[] parameters, ScmEnvironment env) : base(null)
{
_env = env;
_body = body;
_parameters = parameters;
}