// function to fail if called on a package loaded from export data.
// TODO(adonovan): is this a bug or feature? Should this package
// compute accessibility in the same way?
//
// For does not return a path for predeclared names, imported package
// names, local names, and unexported package-level names (except
// types).
//
// Example: given this definition,
//
//	package p
//
//	type T interface {

	w.List = append(w.List, node)
}

// predeclared contains globally known tokens that should not be redefined.
var predeclared = map[string]bool{
	"nil":   true,
	"false": true,
	"true":  true,
}

// declared reports if the body contains a Declare with the given name.
func (w *BodyBase) declared(name string) bool {
	if predeclared[name] {
		// Treat predeclared names as having already been declared.

	// is not a valid constant type.
	//
	// Example:
	//  const c *int = 4
	InvalidConstType

	/* decls > var (+ other variable assignment codes) */

	// UntypedNilUse occurs when the predeclared (untyped) value nil is used to
	// initialize a variable declared without an explicit type.
	//
	// Example:
	//  var x = nil
	UntypedNilUse

		for i, et := range tys {
			if i > 0 {
				b.WriteByte(',')
			}
			b.WriteString(et.String())
		}
		return
	}

	if t == AnyType || t == ByteType || t == RuneType {
		// in %-T mode collapse predeclared aliases with their originals.
		switch mode {
		case fmtTypeIDName, fmtTypeID:
			t = Types[t.Kind()]
		default:
			sconv2(b, t.Sym(), 'S', mode)
			return
		}
	}
	if t == ErrorType {

		}
	}
	return n
}

// AnyValue returns a [Value] for the supplied value.
//
// If the supplied value is of type Value, it is returned
// unmodified.
//
// Given a value of one of Go's predeclared string, bool, or
// (non-complex) numeric types, AnyValue returns a Value of kind
// [KindString], [KindBool], [KindUint64], [KindInt64], or [KindFloat64].
// The width of the original numeric type is not preserved.
//

			}
			seen[name] = true
		}

		// Use the correct obj if the ident is redeclared. The
		// variable's scope starts after the declaration; so we
		// must use Scope.Lookup here and call Scope.Insert
		// (via check.declare) later.
		if alt := scope.Lookup(name); alt != nil {
			check.recordUse(ident, alt)
			// redeclared object must be a variable
			if obj, _ := alt.(*Var); obj != nil {
				lhsVars[i] = obj

			}
			seen[name] = true
		}

		// Use the correct obj if the ident is redeclared. The
		// variable's scope starts after the declaration; so we
		// must use Scope.Lookup here and call Scope.Insert
		// (via check.declare) later.
		if alt := scope.Lookup(name); alt != nil {
			check.recordUse(ident, alt)
			// redeclared object must be a variable
			if obj, _ := alt.(*Var); obj != nil {
				lhsVars[i] = obj

	// InvalidConstType occurs when the underlying type in a const declaration
	// is not a valid constant type.
	//
	// Example:
	//  const c *int = 4
	InvalidConstType

	// UntypedNilUse occurs when the predeclared (untyped) value nil is used to
	// initialize a variable declared without an explicit type.
	//
	// Example:
	//  var x = nil
	UntypedNilUse

	f32 = imag /* ERRORx `cannot use .* in assignment` */ (c128)
	f64 = imag /* ERRORx `cannot use .* in assignment` */ (c64)
	imag /* ERROR "not used" */ (c64)
	_, _ = f32, f64

	// complex type may not be predeclared
	type C64 complex64
	type C128 complex128
	var x64 C64
	var x128 C128
	f32 = imag(x64)
	f64 = imag(x128)

	var a []complex64
	_ = imag(a... /* ERROR "invalid use of ..." */ )

	switch tv.mode {
	case constant_, variable, mapindex, value, nilvalue, commaok, commaerr:
		return true
	}
	return false
}

// IsNil reports whether the corresponding expression denotes the
// predeclared value nil. Depending on context, it may have been
// given a type different from UntypedNil.
func (tv TypeAndValue) IsNil() bool {
	return tv.mode == nilvalue
}