public static ZilObject UNASSIGN(Context ctx, [NotNull] ZilAtom atom, [NotNull] LocalEnvironment env)
{
if (atom == null)
{
throw new ArgumentNullException(nameof(atom));
}
if (env == null)
{
throw new ArgumentNullException(nameof(env));
}
env.SetLocalVal(atom, null);
return(atom);
}
public static ZilObject VALUE(Context ctx, [NotNull] ZilAtom atom, [NotNull] LocalEnvironment env)
{
var result = env.GetLocalVal(atom) ?? ctx.GetGlobalVal(atom);
if (result == null)
{
throw new InterpreterError(
InterpreterMessages._0_Atom_1_Has_No_2_Value,
"VALUE",
atom.ToStringContext(ctx, false),
"local or global");
}
return(result);
}
/// <summary>
/// Creates a new environment, optionally inheriting bindings from a parent environment.
/// </summary>
/// <param name="ctx">The context.</param>
/// <param name="parent">The parent environment, or <see langword="null"/> to not inherit any bindings.</param>
/// <remarks>Changes made to bindings in the parent environment will be visible in the new environment,
/// unless overridden by bindings created in the new environment with <see cref="Rebind"/>.</remarks>
public LocalEnvironment([NotNull] Context ctx, [CanBeNull] LocalEnvironment parent = null)
{
this.ctx = ctx ?? throw new ArgumentNullException(nameof(ctx));
Parent = parent;
}
public static ZilResult EVAL([NotNull] Context ctx, [NotNull] ZilObject value, [NotNull] LocalEnvironment env)
{
return(value.Eval(ctx, env));
}
public static ZilObject BOUND_P([NotNull] Context ctx, [NotNull] ZilAtom atom, [NotNull] LocalEnvironment env)
{
return(env.IsLocalBound(atom) ? ctx.TRUE : ctx.FALSE);
}
public static ZilObject ASSIGNED_P([NotNull] Context ctx, [NotNull] ZilAtom atom, [NotNull] LocalEnvironment env)
{
return(env.GetLocalVal(atom) != null ? ctx.TRUE : ctx.FALSE);
}
public static ZilObject SET(Context ctx, [NotNull] ZilAtom atom, ZilObject value, [NotNull] LocalEnvironment env)
{
env.SetLocalVal(atom, value);
return(value);
}